Thermo Scientific ESCALAB 250 User manual

Monochromated X-Ray
Source with XR5
Electron Gun
Document Number HA600054
Issue 5 (02/07)
Monochromated X-Ray Source with XR5 Electron Gun
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1 Contents
1 Contents ......................................................................................................2
1.1 Figures .......................................................................................................... 3
1.2 Tables ........................................................................................................... 3
2 Introduction .................................................................................................4
2.1 What You Should Have Already Read .......................................................... 4
2.2 Getting Help .................................................................................................. 4
2.3 Health and Safety.......................................................................................... 5
2.3.1 Safety Warnings: ESSENTIAL READING........................................................ 5
2.3.2 Safety Interlocks............................................................................................... 5
3 Description ..................................................................................................8
3.1 Introduction ................................................................................................... 8
3.2 XR5 Electrostatic Electron Gun..................................................................... 9
3.2.1 Cathode............................................................................................................ 9
3.2.2 Anode............................................................................................................... 9
3.3 Water Cooling Circuit .................................................................................. 10
3.4 Monochromator Crystal Assembly .............................................................. 10
3.5 Moving the XR5 Anode ............................................................................... 12
3.6 Monochromator Fine Tuning ....................................................................... 12
3.6.1 Alignment of the Analysis Centre and Microscope Cross Hairs..................... 12
3.7 T352/NT Computer-Controlled Power Supply ............................................. 14
4 Monochromator Operation ......................................................................15
4.1 Avantage Data System Monochromator Controls ....................................... 15
4.1.1 Errors and Warnings ...................................................................................... 16
4.2 Different XR5 Operating Modes .................................................................. 16
4.3 Switching on the Re-circulated Water ......................................................... 17
4.4 Observing the Monochromator Spot ........................................................... 17
4.5 Limits of Operation...................................................................................... 18
5 Maintenance ..............................................................................................19
5.1 Degassing - after a System Vent and Bake ................................................ 19
5.2 Re-alignment after a Bake .......................................................................... 19
5.3 Anode Maintenance .................................................................................... 21
5.4 Replacing Anodes ....................................................................................... 22
5.5 Replacing Filaments/Cathodes ................................................................... 23
5.6 Anode Cap Cleaning ................................................................................... 27
5.7 Ceramic Replacement................................................................................. 27
5.8 Crystal Maintenance ................................................................................... 27
5.9 Fault Finding ............................................................................................... 28
5.10 Fuses Information – for Service Engineers ................................................. 29
6 Index...........................................................................................................30

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1.1 Figures
Figure 2-1: X-ray Sofware Interlocks...................................................................................................... 6
Figure 2-2: Rear View of the T352/NT Showing the Interlock LEDs ...................................................... 6
Figure 3-1: The Monochromator Assembly ............................................................................................ 8
Figure 3-2: Major Features of the XR5 Electron Gun............................................................................. 9
Figure 3.3: The Monochromator Crystal Manipulator........................................................................... 10
Figure 3-4: A Schematic of Bragg X-Ray Diffraction ............................................................................ 11
Figure 3.5: Leg Angle Adjustment ........................................................................................................ 11
Figure 3-6: Adjustment of the Crystal Manipulators ............................................................................. 13
Figure 4-1: Avantage Properties Book ................................................................................................. 15
Figure 4-2: Control Properties Book..................................................................................................... 15
Figure 4-3: Water flow fail light within the Trips.................................................................................... 16
Figure 4-4: Observing the Monochromator Spot Size on a Phosphor Sample .................................... 17
Figure 4-5: Anode Operation Limits for the XR5 Mono. X-ray Source ................................................. 18
Figure 5-1: Crystal Manipulator Viewed from Behind the System........................................................ 20
Figure 5-2: Location of the Anode Shift Drive ...................................................................................... 21
Figure 5-3: XR5 Anode Assembly ........................................................................................................ 22
Figure 5-4: XR5 Anode Orientation ...................................................................................................... 23
Figure 5-5: XR5 Lens and Emitter Assemblies .................................................................................... 24
Figure 5-6: XR5 Emitter Flange Assembly ........................................................................................... 24
Figure 5-7: XR5 Emitter Cup Assembly................................................................................................ 25
Figure 5-8: XR5 Lens Assembly........................................................................................................... 26
1.2 Tables
Table 1: T352 Instrument Interlocks....................................................................................................... 7
Table 2: Specification Outputs for the Monochromator Gun ................................................................ 14
Table 3: Typical Example Set of User Modes ......................................................................................16
Table 4: Fault Finding........................................................................................................................... 29
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2 Introduction
This document covers the overview and basic maintenance of the Monochromated X-
ray Source with an XR5 Small Spot Electron Gun, as would be required by an average
user. Detailed operation of the Sources using the Avantage Software is covered by
using the online manual loaded with the software datasystem. It does not include detail
on the initial installation and setting up of the electron gun or crystals nor any
troubleshooting or maintenance which would require the user to directly access high
voltage. It includes procedures for replacement of certain consumable items such as
anodes and filaments which require the system to be vented and subsequently baked.
2.1 What You Should Have Already Read
New operators should ensure they read and understand the following before using this
document:
xHealth, Safety and Standards Compliance (HA000005) - Which ensures
you fully understand safe working practices when using the ESCALAB 250.
xSystem Overview (HA600050) - Which is designed to introduce new
operators to the ESCALAB 250 system and discusses major components
and design features.
xCommon Operator Procedures (HA600051) - Which explains standard
operator procedures such as loading and positioning samples, vacuum
pressure monitoring and use of the zoom microscope.
xSample Preparation (HA600053) - Which discusses the very important
subject of sample preparation, storage and handling.
2.2 Getting Help
Ensure to clearly state on all e-mails for support are marked either for “Service and
Maintenance”, “Software Support “ or “Applications”
Thermo Fisher Scientific
Birches Industrial Estate
Imberhorne Lane
East Grinstead
West Sussex
RH19 1UB
Phone: [phone]
Fax: [phone]
Email: [email protected]
WWW: http://www.thermofisher.com
Thermo Fisher Scientific reserves the right to alter the specification of its products from
time to time without notice. Although every effort is made to ensure the accuracy of the
information contained within this document it is not warranted or represented by
Thermo Fisher Scientific to be a complete and up-to-date description.

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2.3 Health and Safety
All users should ensure that they read and understand the health and safety document
called “ HA000005 - Health, Safety and Standards Compliance” before carrying out
any operational or engineering work on the ESCALAB 250 system or any of its
associated options.
2.3.1 Safety Warnings: ESSENTIAL READING
The Model T352/NT Power Supply used to control the X-Ray sources produce
LETHAL VOLTAGE OUTPUTS of up to 20kV at 1kW.
The power supply is fitted with an earth-terminal on the rear panel. This EARTH
TERMINAL MUST be connected to the SYSTEM GROUND by the main EARTH
BRAID (supplied as part of the main cable assembly).
The XR5 Mono-X-Ray gun has an M8 tapped bolt hole on the side of the source flange
marked by the safety-earth symbol, for attaching a separate second earth-braid.
It is recommended that this earth braid should also be securely attached to the system
ground and to the XR5 gun source flange before connecting power to the power
supply. This ensures a high conductivity earth return from the gun to ground.
All cables MUST be fully inter-connected before operation.
2.3.2 Safety Interlocks
The system incorporates multiple safety interlocks to prevent personnel becoming
exposed to the Lethal Outputs.
Other interlocks protect the system from loss of vacuum and cooling water.
On no account should any of these interlocks be overridden.
The interlocks are displayed in the software within the “Trips/Interlocks” display as in
GREEN (OK) or RED (FAIL) for the state of the interlocks. Typical “Trips/Interlocks”
displays are shown in Figure 2-1. Occasionally ‘pop up’ warning messages will
appear. After taking note of the message select the OK button. Go into the details
window and look at the Trips / Interlocks, you will see a red FAIL in the appropriate
window. You will need to take the appropriate action to resolve the problem before
setting the Reset button.
In addition the X-Ray On LED on the T153 control panel will NOT be illuminated.
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XR3/XR4/XR5
Interlocks
Figure 2-1: X-ray Sofware Interlocks
A series of LED’s on the rear panel of the T352 Power Supply indicates the safety
interlocks are in place, and indicator illuminated in Red indicates a fault and the unit
will not operate. The cable assembly incorporates integral safety interlocks between
the X-ray source and the power supply.
The supply requires five interlock loops to be closed before the high voltage outputs
can be switched on. The state of the interlocks is reported to the software. To clear an
interlock the physical fault must first be rectified (for example a safety cover must be
fitted properly) and then reset by software before the high voltage outputs can be
switched on. The interlocks require a voltage free closing contact to operate. Shorting
interlocks to earth will not operate them.
INTERLOCK REFERENCES
1 – Twin Anode Cover
2 – Mono Cover
3 – Vacuum Interlock
4 – Water Flow
5 – Cables
Figure 2-2: Rear View of the T352/NT Showing the Interlock LEDs

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Interlock
Name
Interlocked
Tripped By
Inhibit
s
Status Displayed to Operator
TWIN cover XR3/XR4 Twin X-
Ray source
protective cover
being removed.
Power to
source.
Interlock display in software will display FAIL in
RED
In addition light “1” LED on the rear of the power
supply will illuminate RED.
MONO cover XR5 Mono Covers
Source Protective
cover being
removed.
Power to
source.
Interlock display in software will display FAIL in
RED
In addition light “2” LED on the rear of the power
supply will illuminate RED.
VACUUM Main chamber (ion
gauge) pressure
above
1x10-6 mbar
Power to
source.
Interlock display in software will display FAIL in
RED
In addition light “3” LED on the rear of the power
supply will illuminate RED.
Relay A on Ion Gauge Controller (IGC) LCD
display:
LED On = Enabled
LED Off = Tripped
WATER flow Water flow through
the X-Ray source
(XR4 or MXR1)
drops below 2.8
l/min
Power to
source.
Interlock display in software will display FAIL in
RED
In addition light “4” LED on the rear of the power
supply will illuminate RED.
CABLES Cables removed
from rear of
T352/NT power
supply
Power to
source.
Interlock display in software will display FAIL in
RED
In addition light “5” LED on the rear of the power
supply will illuminate RED.
Table 1: T352 Instrument Interlocks
There are additional safety features built into the T352/NT power supply that will inhibit
power to the X-ray source but will display as a “pop-up” box by the Avantage software,
they include:-
xTemperature in T352 Power Supply rises to unacceptable levels.
xCurrent drawn from T352 Power Supply HV greater than 60 mA.
xDrain from HV through X-ray water lines greater than 20 mA.
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3 Description
3.1 Introduction
The Monochromated X-Ray Source produces X-Rays which have well defined energy
resolution and are micro-focussed onto the sample to give a spatially defined area of
analysis. To achieve this several distinct components are employed. Firstly there is an
electron gun, the XR5, designed to provide a high power source of focused electrons
at energies of up to 15kV. These electrons impact on the anode, in this case an
aluminium coated version, to produce X-Rays at an energy of around 1486.6eV.
The X-Rays are then diffracted by a pair of quartz crystals which are arranged such
that the angle between the crystal lattice and the X-Rays is the appropriate Bragg
angle. The diffracted X-Rays are thus monochromated to give a pure Al KDbeam (of
much lower energy spread). The crystals are also shaped and positioned so that the
diffracted X-Rays are focussed into a well defined spot on the sample surface at the
analysis position.
The XR5 electron gun and anode voltage are controlled by a single power supply, the
T352/NT. This supply has no manual user interfaces, being controlled entirely from the
Avantage Datasystem.
The ESCALAB 250 monochromator system consists of 5 major components:
xXR5 Electrostatic Electron Gun
xMonochromator Water System
xT352/NT Digital X-ray Supply
xMonochromator Crystal Assembly
xData System Monochromator Control Software.
Figure 3-1: The Monochromator Assembly

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3.2 XR5 Electrostatic Electron Gun
The XR5 gun assembly forms the source of the monochromatic X-ray beam optics
used for the production of Al KDX-rays in the monochromator system. It consists of an
electron-bombardment-heated emitter (cathode), a control electrode, an electrostatic
lens and a water cooled aluminium anode as shown schematically in Figure 3-2. The
XR5 operates over a power range of <10 W to 200 W corresponding to an electron
spot size on the anode in the range of <100 Pm to 1 mm.
The XR5 consists of a tantalum emitter button, (the cathode), a pinch-off "Wehnelt"
electrode, an Einzel lens and an aluminium anode.
The beam spot-size on the anode is determined by the Focus lens setting, the beam
energy, (i.e. the HT voltage), the cathode bias and, under low-energy/high-current
conditions, by the beam current.
The heat deposited onto the anode is dissipated by water-cooling which is floating at
HT potential. (This results in a leakage current from the HT power supply unit to
ground.)
Figure 3-2: Major Features of the XR5 Electron Gun
3.2.1 Cathode
The cathode emission current is determined by the "Bombard" power, the Cathode
Bias voltage (which biases the cathode positive from ground), and the HT voltage
which biases the anode and the 2 outer segments of the Einzel lens. The cathode can
be driven in temperature-limited or space-charge-limited mode, depending on the
chosen operating parameters values. The cathode is heated by energetic electron
bombardment from the filament.
3.2.2 Anode
The anode is actually an aluminium thin-film deposited on a copper base. Since the
coating will degrade over time the anode consists of a 25mm strip which can be
manually traversed through the electron beam by a mechanical transfer mechanism to
expose a fresh surface when necessary. The maximum beam-spot-diameter used in
practise is less than 1mm, so that typically more than 20 fresh sites are available, and
so down-time for anode exchange is minimised.
The beam spot size on the anode is determined by the focus lens setting, the beam
energy and, under low energy/high current conditions, the beam current.
The heat generated in the anode is removed by water-cooling which is floating at HT
potential. This results in a small leakage current from the HT supply through the water
lines to ground.
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3.3 Water Cooling Circuit
The ESCALAB 250 water system provides cooling for the XR5 Monochromator source
and XR4 Twin Anode option (if fitted).
The cooling circuit uses mains water or a re-circulator as its input and then increases
the flow through the X-Ray source by use of a booster pump. The control of the booster
pump, and of the solenoid valves which switch the water flow between the twin anode (if
fitted) and mono source is by the datasystem via the T352/NT power supply.
Both the twin anode and mono anode are floating at high voltage and have water
flowing through them. There is thus electrical current flowing through the water pipes
to ground, termed the "drain", which is loading the power supply, with a maximum
value of 20mA allowed. It is important to keep the conductance of the water as low as
possible. The conductance should be less than 0.01 Siemens/metre.
The anodes used in the XR5 Monochromator source and XR4 Twin Anode option both
consist of a thin layer of aluminium (or magnesium) coated onto a water-cooled copper
wall. It is essential that an adequate turbulent flow of water is present for both of these
sources.
The total flow rate is monitored; if this rate falls below a set level an interlock is tripped.
This factory set trip-level prevents any damage to the X-ray sources due to water flow
problems, provided that the guns are operated within recommended limits. The input
flow is filtered and the flows are selected by solenoid valves according to the gun
selection and operating mode as set by the Avantage data system.
3.4 Monochromator Crystal Assembly
Al KDX-Rays from the anode are diffracted by the twin crystals onto the sample. The
shape of the quartz crystals is such that the small area of X-Ray generation on the
anode is focussed onto the sample. The Bragg diffraction from the crystal lattice
provides the energy filtereing of the final X-Ray beam.
The crystals can be individually manipulated in the dispersive and non-dispersive
directions as well as in height, via the set of 6 manipulators on the back of the
manipulator assembly. These adjustments are made from the outside of the vacuum
system while the monochromator is running. In addition, the position of the e-gun and
anode can be moved, effectively changing the Bragg Angle. All of these adjustments
are made at the time of installation and do not need to be routinely changed by the
operator. The only exceptions to this are slight movements of the mono spot position
using the dispersive and non-dispersive adjusters after a bakeout.
Changing the height of one of the crystals will alter the energy of the crystal’s X-Ray
beam. At installation the heights of crystals are matched so that the energy of the X-
Rays produced by each crystal is the same. If the height adjustment of a crystal is
changed it will cause a mismatch in the energies of the two X-Ray spots generated by
the crystals causing a loss in spectral and spatial resolution.
Figure 3.3: The Monochromator Crystal Manipulator

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To focus the X-rays from the source to a spot on the sample, the two quartz crystals
must be formed to the correct geometry. This not only provides point to point focusing
by mirror reflection but also maintains a constant angle of diffraction at the surface,
which corresponds to the Bragg angle.
Figure 3-4: A Schematic of Bragg X-Ray Diffraction
The Bragg angle is critical to the monochromator performance and is related to the
crystal lattice spacing and the wavelength of incident X-rays. Only X-rays of a certain
wavelength incident to the crystal lattice structure at a specific angle will be reflected to
the correct point; this angle is the Bragg angle.
The ESCALAB 250 uses an apertured toroidal geometry on a 500 mm Rowland Circle
to give the highest possible energy resolution. Each crystal substrate is machined to
the exact form required and a thin single-crystal quartz wafer is then bonded to its
surface.
This crystal assembly is then mounted in a precision mechanism as shown in Figure
3.3. This assembly allows the orientation of the crystal to be set precisely, using two
sets of three external micrometers without venting the system.
The lower leg assembly provides an additional adjustment. This adjustment enables
the “Bragg” angle between the anode and both crystals to be optimised; it is frequently
referred to as the 'Leg Angle' as shown in Figure 3.5.
Figure 3.5: Leg Angle Adjustment
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3.5 Moving the XR5 Anode
If degradation of the aluminium anode does occur a new area of anode can be
selected by moving the anode with the linear transfer drive mechanism until a
satisfactory signal level is restored. The XR5 monochromator has been specifically
designed so that the anode can be safely moved while the monochromator source is
running.
The performance of the anode is most effectively checked by measuring the sensitivity
for the Ag3d5/2 XPS line on a sputter-cleaned standard silver sample in standard
analyser modes. However when adjusting the anode position observation of either the
spot on a phosphor sample or any high level XPS signal should suffice as a monitor.
The linear motion drive moves the anode by 0.8 mm per turn. The range of motion and
the useful anode length are both 25 mm. A fraction of a turn (for example a half turn)
will usually be enough to expose a new aluminium film area.
3.6 Monochromator Fine Tuning
Complete alignment and set up of standard operating conditions will generally be
carried out by Thermo Fisher Scientific service engineers and most operators will not
need to be concerned with any significant monochromator alignment. However
monochromator fine-tuning is a procedure that both engineers and operators need to
be familiar with.
In order to maintain optimum performance of the ESCALAB 250 the instrument
operator should check that the anode surface is in good condition on a daily basis, and
renew this surface as described in the previous section. The operator should also
regularly check (a minimum of once a week) that the analysis position (as defined by
the microscope cross hairs and/or XP imaging) coincides with the true position of the
X-ray beam on the sample.
For these simple alignment checks it is essential to have a phosphor sample (such as
Thermo Scientific Part No. SK1066-004) mounted on a sample holder, together with a
piece of silver, or silver on silicon, and a TEM grid sample mounted over a hole. It is
usually convenient to leave such a sample set-up mounted permanently on a sample
block, and to leave it in the bottom of the FEAL when not required so that it remains
free from contamination.
3.6.1 Alignment of the Analysis Centre and Microscope Cross Hairs
Minor misalignments (<200 Pm) of the microscope cross hairs and monochromator
can develop over time. These can quickly be corrected without significantly affecting
the instrument performance.
Before making any adjustments to the monochromator ensure that the monochromator
has had sufficient time to ‘warm up’, typically at least one hour. Frequently apparent
minor misalignments of the monochromator spots are due to insufficient time being
allowed for the gun to stabilise at the operating conditions.
1. Place a standard phosphor sample and a standard silver-on-silicon sample
side by side on a sample holder. For convenience fit spacers under the thinner
sample to make the sample heights equal. Ensure that the silver sample has a
good earth contact.
2. Introduce these samples to the system.
3. Move the phosphor sample to the analysis position and check that the
phosphor surface is in sharp focus on the microscope display monitor.
4. Start the mono source and set up a visible beam with the smallest spot size.

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5. Note the position of the beam spot relative to the cross hairs centre.
6. If the spots are less than 1 mm from the cross hairs centre the spot can
probably be re-centred without causing a significant change in the detection
sensitivity.
7. Record a spectrum from any convenient sample (e.g. a silver standard) before
making any changes and then use the two lateral shift micrometers on the
crystal manipulator as shown in to adjust the beam position to the cross hairs
centre. Do not adjust the height or leg angle of the crystal manipulator. Re-
record the spectrum as before and if the count rate has not fallen by more than
5% there is no need to realign further. If the spot is more than 1 mm from the
centre or if this procedure needs to be repeated on more than three occasions,
then a more complete realignment should be performed. Only if a major service
or repair has been undertaken should a more extensive re-alignment be
necessary.
Figure 3-6: Adjustment of the Crystal Manipulators
Lateral Shift
Micrometers
Lateral Shift
Micrometers
Height Change =
Diagonal Movement of
Spot (NOT Wanted!)
Dispersive Change =
Vertical Movement of Spot
(Along HPT X-axis)
Non-Dispersive Change =
Horizontal Movement of Spot
(On the HPT Y-axis)
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3.7 T352/NT Computer-Controlled Power Supply
The power supply is a multiple output unit generating all the voltages needed to
operate both the Twin Anode and Monochromator guns. It also controls the cooling
water pumping for both guns.
The specification of the outputs for the monochromator gun are shown below in an
abbreviated form.
Output Maximum Operating Ratings
Main HT 15kV/60mA (Normal operating)
or 20kV/20mA (Source conditioning)
Monochromator Filament 2.5A
Bombard 3000V
Cathode 1200V
Focus 3500V
Table 2: Specification Outputs for the Monochromator Gun
Control is entirely from the computer, no manual controls are fitted except for the rear
panel mains power switch.
The supply requires five interlock loops: Vacuum; Water-flow; Twin anode cover; Mono
cover; Mono source cable-guard, to be closed before the high voltage outputs can be
switched on. The state of the interlocks is reported to the software. To clear an
interlock the physical fault must first be rectified (e.g. replace a safety cover) and then
reset by software before the high voltage outputs can be switched on. The interlocks
require a voltage free closing contact to operate. Shorting interlocks to earth will not
operate them.
Communication between the control computer and the power supply is via an optical
modem and a fibre optic serial line from an RS232 port (generally COM1). The mains
power to the T352/NT is NOT vacuum-interlocked (although the outputs are) so that
the communications circuitry is always powered even when T352/NT output trips
occur. The output circuitry is protected by the separate vacuum interlock.
The T352/NT outputs will trip if any interlock fails or if certain levels are exceeded. The
most relevant of these are the Leakage Current and the HT Current. The leakage
current is due to the conductivity of the anodes cooling water and the HT current is the
total current comprising leakage current + electron-beam current. Trips will occur if the
leakage current exceeds 20mA, (so water purity must be maintained periodically if the
drain current becomes too high), or if the HT current exceeds 60mA.
The state of all outputs, interlocks, trips and the values of achieved voltages and
currents are displayed by the control software.
There are no user serviceable parts in the T352/NT power supply. Contact your local
agent for service.

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4 Monochromator Operation
The ESCALAB 250 small spot monochromator is entirely computer controlled. Once
the monochromator has been degassed all the operator has to do is select the pre-set
monochromator conditions required and the Avantage data system does the rest.
This document covers basic operation of the monochromator, i.e. turning it on and off
and selecting pre-set conditions. For full details on the Monochromator operation refer
to the Avantage on-line manual.
4.1 Avantage Data System Monochromator Controls
The 'X-Ray Control' is addressed by inserting a “Source Object” in the “Experiment
Tree” , shown selected in Figure 4-1 may also be assessed from “Instruments” tab
but normal operation is through inserting an experiment object.
Figure 4-1: Avantage Properties Book
Selection of the Monochromator source “Mono X-ray Gun” opens the “Control
Properties Book” which provides a menu of stored operating conditions for the Mono
Source. A “Details” button opens a window displaying all the control parameters.
The Control Properties Book permits the user to select preset operating conditions
where most of the operating conditions have already been determined and the
operator has only a few basic decisions to make before starting the source.
Gun control is via a simple Control tab (X-Ray mode), an example of which is shown
in Figure 4-2
Figure 4-2: Control Properties Book
Clicking on the Spot/Power drop down list presents the user with a number of
predefined power and spot size settings. Once an appropriate Beam Size has been
chosen the Apply button should then be selected.
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4.1.1 Errors and Warnings
As the monochromator is ramping up to the desired operating point the data system
will check for any problems and report these as a warning window.
If an Error does occur, the data system will display a warning dialogue and instruct the
operator in what to do next.
Occasionally ‘pop up’ warning messages will appear. After taking note of the message
select the OK button. Go into the “Details” window and look at the Trips / Interlocks,
you will see a red Fail in the appropriate window. You will need to take the appropriate
action to resolve the problem before setting the Reset button (see Figure 4-3).
Figure 4-3: Water flow fail light within the Trips
4.2 Different XR5 Operating Modes
There are in total up to 20 pre-set operating modes. 11 of these have been assigned
to different stages of degas and are therefore not used during normal operating
conditions. These are discussed further in the maintenance section of this manual. A
typical set of user modes follows, although individual cases may be tailored to
individual systems or customers requirements
Standby -500Pm [10kV 60W]
Default -120Pm [15kV 22W]
Default -150Pm [15kV 30W]
Default -200Pm [15kV 45W]
Default -250Pm [15kV 55W]
Default -320Pm [15kV 75W]
Default -400Pm [15kV 100W]
Default -500Pm [15kV 150W]
Default -650Pm [15kV 200W]
DEGAS_1-Keep_P_below_1e-7mb (10 min)
DEGAS_2-Keep_P_below_1e-7mb (10 min)
DEGAS_3-Keep_P_below_1e-7mb (20 min)
DEGAS_4-Keep_P_below_1e-7mb (1hr)
DEGAS_5-Keep_P_below_1e-7mb (10 min)
DEGAS_6-Keep_P_below_1e-7mb (20 min)
DEGAS_7-Keep_P_below_1e-7mb (1hr)
DEGAS_8-Keep_P_below_1e-7mb (10hr)
DEGAS_9-Keep_P_below_1e-7mb (1hr)
DEGAS_10-Keep_P_below_1e-7mb (1hr)
DEGAS_Large_spot [10kV 100W]
Table 3: Typical Example Set of User Modes

Monochromated X-Ray Source with XR5 Electron Gun
Issue 5 Monochromator and XR5 (HA600054)
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Each of the lens modes gives in its title three pieces of information.
(i) The size of the final X-Ray spot in Pm. This is defined the 20% to 80%
points of the spot when moved over a "knife-edge".
(ii) The beam energy, in kVolts.
(iii) The power in Watts of the electron source on the anode.
The first operation mode in the list is entitled "Standby" and is a relatively low power
X-Ray beam into a 500Pm spot. This is designed to be used for setting up
experiments between acquisitions or during transfer of samples. The low power
density on the anode results in minimal "wear and tear" of the source.
When running the source the operation mode selected will depend upon the type of
experiment. The higher power modes give more signal but cover a larger area. The
lower power modes give less signal but can be used for source defined selected
area XPS.
It should be noted that there is a “warm up time” associated with the XR5 gun.
During this time the monochromated spot will appear to move on the sample surface
as the gun reaches a steady state condition. It is recommended that the gun is left in
the standby condition for 15-30 minutes before acquisition or alignment so that a
stead state is obtained.
4.3 Switching on the Re-circulated Water
The first task to carry out is to switch on the re-circulated water supply. Power for this
may be supplied from the system or from a separate mains circuit in the laboratory. If
this is not switched on then when an attempt is made to switch on the monochromator
the booster pump will run dry, be much louder than normal and possibly be damaged.
The monochromator gun will not turn on as the water flow interlock will have failed.
4.4 Observing the Monochromator Spot
For fine-tuning of the monochromator alignment or simple checking that the
monochromator is working properly it is often very useful to observe the
monochromator spot.
This is most easily achieved with a standard phosphor sample as demonstrated in
Figure 4-4.
Figure 4-4: Observing the Monochromator Spot Size on a Phosphor Sample
Monochromated X-Ray Source with XR5 Electron Gun
Monochromator and XR5 (HA600054) Issue 5
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4.5 Limits of Operation
The anode has set limits at which it can operate, exceeding these limits can damage
the anode and shorten its life time. These limits are shown in Figure 4-5. It is very
possible to cause some damage to the source, particularly to filaments and anode-
coatings if the figures are exceeded so expert knowledge is required to avoid these
conditions. Although the settings can be freely accessed from the XR5 user window it
is not recommended that the user should alter any value within this window, except
under instruction from a Thermo Fisher Scientific engineer. Hard copies of the values
set up for each mode will be made at the time of installation.
All the preset monochromated X-ray spot conditions all lie within the safe operation
conditions.
Figure 4-5: Anode Operation Limits for the XR5 Mono. X-ray Source

Monochromated X-Ray Source with XR5 Electron Gun
Issue 5 Monochromator and XR5 (HA600054)
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5 Maintenance
This section includes various maintenance tasks ranging in complexity from simple
tasks such as degassing the source after a bake to tasks requiring more attention such
as replacing consumable parts. Before undertaking any task read fully the instructions
and ensure any replacement items and necessary tools are at hand. If any doubt
remains as to how to complete the task it is better not to attempt it but to seek advice.
5.1 Degassing - after a System Vent and Bake
After the system has been vented and baked it is important to run up the gun slowly to
ensure that any adsorbed gas is liberated and pumped away without any
contamination of the source or risk of high voltage breakdown. To assist in this task a
set of 10 degas levels have been created. The user should select the first degas level,
switch on the gun and monitor the main chamber pressure. The degas levels can then
be stepped through one by one but at all times the main chamber pressure should
remain below 1x10-7mBar. If the pressure rises to this value then the gun should be
switched back to the previous level.
The full degas and conditioning procedure for the complete system, including the
monochromator, is detailed in the document “HA600052 – Baking and Degassing”.
5.2 Re-alignment after a Bake
After the system is baked it may be found that the spatial alignment of the mono spots
have moved very slightly from their original position. This may be too small to notice
but a check on their position can be simply made using either of the following methods.
Basic Method:
1. Ensure the CCD viewing camera is aligned with the analyser analysis position,
which can be done by using the flood gun imaging.
2. Put a phosphor sample into the system and adjust its height so that the surface
is in focus on the CCD camera monitor.
3. Switch on the mono and observe the two spots on the monitor which may be
completely superimposed upon one other (adjustment of the sample height will
confirm this, as the spots will diverge and converge as the sample is raised and
lowered).
4. Position each spot by moving the dispersive and non-dispersive adjusters on the
crystal manipulator, do NOT adjust the heights of the crystal as this will change
the energy of the X-Ray spot from each crystal, to coincide with the cross-hairs
on the viewing camera. These adjusters are very sensitive so only small
adjustments should be made. Never adjust the manipulator without viewing the
spot movement as once the spot moves off the phosphor it can be difficult to
relocate. The dispersive adjuster moves the spots from front to back of the
system and the non-dispersive adjuster from side to side.
5. The mono spots are now aligned.
Monochromated X-Ray Source with XR5 Electron Gun
Monochromator and XR5 (HA600054) Issue 5
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Figure 5-1: Crystal Manipulator Viewed from Behind the System
More Accurate Method: (Experienced users of imaging ESCALAB’S)
1. Ensure the CCD viewing camera is aligned with the analyser analysis position
and that the focus heights are coincident, which can be done by using the flood
gun imaging.
2. Using a homogeneous flat sample such as silver, at the correct height according
to the CCD camera, run XPS imaging in continuous, monitoring a strong peak
such as Ag3d5/2with a field of view of 1mm (or the largest available).
3. Switch on the mono and open the acceptance aperture from the normal position
of 2 to around 4 or 5. This will allow the spots to be seen in real time. Each spot
will have the appearance of a swarm of bees.
4. Position each spot by moving the dispersive and non-dispersive adjusters on the
crystal manipulator, to coincide with the centre of the frame-store monitor.
These adjusters are very sensitive so only small adjustments should be made.
Never adjust the manipulator without viewing the spot movement as once the
spot moves off the phosphor it can be difficult to relocate. The dispersive
adjuster moves the spots from front to back of the system and the non-
dispersive adjuster from side to side.
5. Change the imaging field of view to 120Pm and repeat 4 above for greater
accuracy.
6. The mono spots are now aligned.
Non-Dispersive Change =
Horizontal Movement of Spot
(On the HPT Y-axis)
Height Change =
Diagonal Movement of
Spot (NOT Wanted!)
Dispersive Charge =
Vertical Movement of Spot
(Along HPT X-axis

Monochromated X-Ray Source with XR5 Electron Gun
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5.3 Anode Maintenance
The anode has an active length of 25mm, but the electron gun spot on the anode is of
the order of 1mm in diameter or less. Over a time, the period of which depends upon
the power density impinging upon the anode, the X-Ray signal obtained will decrease
in amplitude due to degradation of the coating. When the signal has dropped to
unacceptable levels the anode can be moved to a fresh area by turning the knurled
knob on the “Z” drive on which the anode is mounted. This is best achieved by
monitoring the signal using the ratemeter so the improvement can be ascertained in
combination with viewing the spots on a suitable phosphor sample. In general a
movement of 1mm or less should be sufficient, which corresponds to a little less than
one turn of the drive. This will give a total of 25 fresh areas on the anode.
Figure 5-2: Location of the Anode Shift Drive
Follow the procedure below to replace the monochromator anode surface:
1. Set up the ESCALAB 250 system so that you can observe the intensity of the
monochromator source, either by observing the spot on a phosphor sample or
an XPS signal, such as Ag3d5/2 from a standard silver sample.
2. Locate the anode linear motion drive with reference to Figure 5-2.
3. Rotate the linear motion drive to move the anode by less than 1 turn (< 0.8
mm) in either direction, or until the signal level or spot brightness are restored
to their normal level and further movement has no effect.
4. If observing the spot on a phosphor, burn marks will be visible as dark patches.
Move the anode until these are not visible in the beam spot diameter that is
required. It is wise to start at one end of a new anode and then to
systematically move the anode in the same direction to obtain each fresh
surface. In this way it is possible to judge what fraction of the anode has been
used at any time and to plan to replace the anode as part of a routine
maintenance schedule.
Monochromated X-Ray Source with XR5 Electron Gun
Monochromator and XR5 (HA600054) Issue 5
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5.4 Replacing Anodes
In general, the anode will need replacing only when all the aluminium coating has been
degraded sufficiently to attenuate the X-Ray flux below acceptable levels along its
entire length.
If the anode condition requires its replacement, the vacuum system will have to be fully
shut down and vented to dry nitrogen.
Figure 5-3: XR5 Anode Assembly
Refer to Figure 5-3: XR5 Anode Assembly.
1. Unplug the cables from the XR5.
2. Expose the anode terminations by withdrawing the anode safety shield. This is
identical to the shield covering the Twin Anode gun, and requires the loosening
of the M4 x 8 cap head clamp screws and then a twist to disengage from the
locking pins mounted in the side of the 70mm flange of the anode assembly.
3. The PTFE tube covering the external end of the anode can now be unscrewed
from its mating PTFE collar. This exposes the end of the anode with the HT
connector and 2 cooling pipes attached.
4. Unplug the HT connector
5. Unplug the 2 cooling line connectors from the anode cap. This may require the
use of a tool such as a flat blade screwdriver to lever the connectors away from
the anode cap. There will be a slight spillage of cooling water at this stage. Bear
in mind that the anode will also contain a few cc of water when removed - watch
out for your clothes!
6. Loosen the locking screw from the end ferrule of the cooling/HT steel conduit
and withdraw the conduit from the anode-shield-support assembly.
7. Unscrew the 4-off M4 x 12 cap head screws from the steel collar retainer for the
PTFE collar. Remove these items and the PTFE tube from the anode assembly.
8. Retract the Linear Motion Drive fully.
9. Remove the 6-off M4 x 12 cap head screws from the FC19 mini-flange of the
anode.
10. Carefully withdraw the anode from the gun assembly. It should withdraw
smoothly. If any resistance is felt inspect the end of the copper tube after
withdrawal for signs of gouging. If gouging is apparent the anode-locating-cap
will need its bore to be cleaned.
11. If the anode was extracted smoothly with no signs of gouging a new anode can
be fitted, with a new FC19 copper gasket. This should fit smoothly into place
without need of force.
12. When fitting the anode note the orientation of the anode-flat relative to the gun
axis - reference the Figure 5-4 showing XR5 Anode Orientation.

Monochromated X-Ray Source with XR5 Electron Gun
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This is the active anode surface and must face towards the gun cathode.
The anode mini-flange is marked with an "A" adjacent to the bolt hole in line with
this flat.
Make sure that the "A" is facing towards the gun source.
x
x
Figure 5-4: XR5 Anode Orientation
13. Replace all the removed items in reverse order to the removal sequence.
14. Place the PTFE HT shield tube over the anode and loosely refit the PTFE collar
and retaining flange before fitting the cooling/HT conduit
15. Make sure the cooling pipe connectors are driven fully on to the anode-cap-
pipes.
16. Clamp the retaining collar and screw on the PTFE HT shield.
17. Refit the HT protection cover, remembering to twist home and tighten the clamp
screws. This operates a microswitch which is part of the safety interlocks for the
X-Ray power supply.
18. Pump down and bake the system before use.
5.5 Replacing Filaments/Cathodes
The emitter should normally give long lifetime, well in excess of 1000 hours, provided
that it is operated in good vacuum conditions and within the recommended
voltage/power limits.
If the emitter condition requires its replacement, the vacuum system will have to be
fully shut down and vented to dry nitrogen.
As a further precaution disconnect the mains supply from the T352/NT X-Ray power
supply.
Refer to the Figure 5-5: XR5 Lens and Emitter Assemblies.
1. Remove the M8 x 16 hex head bolt clamping the XR5 earth strap.
2. Unplug the leads from the XR5.
3. Do not unbolt the 70mm/FC38 11-pin feedthrough flange. This is unnecessary
except when replacing the feedthrough.
4. Remove all the M8 x 35 hex head bolts except for 3 at well-spaced positions to
retain the main 114mm/FC64 flange.
5. Unscrew the last 3 bolts in sequence 1-turn at a time. This is to symmetrically
release the loading from the spring-loaded emitter cup.
6. After about 3mm retraction the spring-loading is released and the flange can be
fully removed.
Stand the flange on a clean work surface with the emitter facing up.
Monochromated X-Ray Source with XR5 Electron Gun
Monochromator and XR5 (HA600054) Issue 5
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Figure 5-5: XR5 Lens and Emitter Assemblies
Refer to Figure 5-6: XR5 Emitter Flange Assembly.
7. Note the electrical connections: 1 Focus; 2 filament; 1 cathode; 1 double pin
interlock and 1 ground.
8. Note the pre-set height of the emitter cup assembly from the vacuum flange
surface.
9. Loosen the 3 spring loaded screws in sequence, a few turns at a time, until fully
removed.
10. Using tweezers, disconnect the (2) filament and (1) cathode lead from the pin
base.
11. Place the emitter cup assembly on the work surface with the leads facing up.
Figure 5-6: XR5 Emitter Flange Assembly

Monochromated X-Ray Source with XR5 Electron Gun
Issue 5 Monochromator and XR5 (HA600054)
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Refer to Figure 5-7: XR5 Emitter Cup Assembly.
Use kit number PRT0001/UG, which comprises of :
1 off Filament/Cathode Assembly.
1 off Spacer
3 off Clamps - (not required on this assembly)
3 off Special Screws - (not required on this assembly)
1 off Retaining Star Washer
12. Using a jewellers small screwdriver or similar tool, carefully free the tangs of the
star-washer, in circumferential sequence, from the retaining lip inside the emitter
cup. The washer can be reused, if the tangs are straightened out first, but a new
washer is supplied with the emitter components.
13. Lift out the filament/cathode ceramic-button assembly.
14. Discard any shim-ring(s) fitted between the cathode-button and the emitter cup.
15. Carefully fit the Filament/Cathode Assembly with the shim supplied in the kit into
the emitter cup, making sure that the cathode connection-peg is placed
diametrically opposite (away from) the large slot in the emitter-cup-flange.
16. Gently press the star-washer into place, making sure that all of the tangs are
trapped beneath the retaining lip of the cup.
17. Make sure that the cathode peg and mating slot in the filament-button, and the
mating slot in the star washer, are orientated symmetrically with respect to each
other, to maximise break-down gaps between cathode and filament and both to
ground.
18. Refit the cup assembly to the main flange, and before setting the cup-to-flange
height, connect the filament and cathode leads to the pin-base. Check that all
sockets are fully mated to the pin-base and on the correct pins.
19. Screw in the spring-loaded screws until the correct height is set.
20. Ensure the Focus spring-connection is located on its retaining ceramic "top-hat".
21. Refit the flange assembly to the gun body initially with 3 or 4 bolts tightened
gradually in sequence until metal-to-metal contact is made between flanges.
Use a new FC64 copper gasket and make sure that the flange is offered to the
gun in the correct orientation. The main flange is labelled "TOP" on its
circumference adjacent to the focus connection. This should be in the top
vertical position when refitted to the gun on the system.
22. Check the pin base for filament and interlock continuity and all other pins for
electrical isolation.
23. Fully tighten the flange with all bolts fitted.
24. Pump down and bake the system before use.
Figure 5-7: XR5 Emitter Cup Assembly
Discard Shims and
replace with Shim
supplied with kit
Centralise
Filament/Cathode Assembly
button slot with slot in Star
Washer
View of Star Washer
and Filament
Cathode Button
Individual Filament and Cathode
Assemblies replaced with a single
Filament/Cathode Assembly
Star Washer
Monochromated X-Ray Source with XR5 Electron Gun
Monochromator and XR5 (HA600054) Issue 5
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The LENS assembly will need to be removed to cure either:
1. Anode scouring
2. Excessive HT "ticks" and breakdown
Item 1. can be achieved without special jigs, whereas item 2 requires expertise and
special jigs: see Ceramics Replacement
Refer to Figure 5-5: XR5 Lens and Emitter Assemblies.
First follow the instructions for Anode Replacement since the Lens assembly cannot
be removed until the anode is removed. Any attempt to remove the lens assembly first
will cause damage!
Secondly, follow the initial steps for removal of the Emitter assembly, to expose the
lens assembly.









Figure 5-8: XR5 Lens Assembly
Refer to Figure 5-8: XR5 Lens Assembly.
Figure 5-8: XR5 Lens AssemblyThe lens assembly is fitted into the main vacuum
housing of the XR5, through the 114mm/FC70 source mounting flange.
To assist in handling the lens assembly (weight ~1 Kg), 3-off M4 screws can be fitted
in the 3 tapped holes in the lens-support flange. Do not attempt to screw these in fully
until the clamping screws have been loosened (next step).
1. Unscrew the 6-off M2 x 8 cheese-head screws that clamp the lens assembly
into the vacuum housing.
2. Carefully withdraw the lens assembly.
Do not attempt to loosen any other screws before reading the section "Ceramics
Replacement".

Monochromated X-Ray Source with XR5 Electron Gun
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5.6 Anode Cap Cleaning
This is required if the anode shows signs of binding during use of the linear motion
drive.
Refer to Figure 5-4 and Figure 5-8.
1. The lens assembly must be removed from the vacuum housing (follow Lens
Removal procedure)
2. Inspect the anode-location bore-hole for any debris adhering to the bore walls.
The bore is coated with a solid lubricant. If this has been abraded the anode cap
should be exchanged for a reconditioned one.
3. Unscrew the 2-off M3 x 25 and 1-off M3 x 12 cap head screws and withdraw the
anode-cap.
4. Fit the replacement and refit the clamp screws. The orientation of the anode-cap
will have to be checked by refitting the lens assembly in the vacuum housing
and inserting the anode without bolting the anode vacuum flange. The anode
flange should be naturally aligned with its mating flange. If any force is needed
to achieve this alignment, note the direction of displacement, remove the lens
assembly, score the anode-cap and its mounting-base to identify its initial
orientation and then loosen the 3-off M3 screws to allow a suitable rotational
adjustment. Repeat this alignment test procedure until satisfactory alignment is
attained.
5. Refit the gun components in reverse order to the removal procedures.
6. Pump down and bake the system before use.
5.7 Ceramic Replacement
Replacement or cleaning of ceramics is required if HT ticks become a problem. Since
this job requires total disassembly of the gun, and re-assembly requires the use of
special alignment jigs, it is recommended that this be done by qualified service
engineers.
5.8 Crystal Maintenance
The crystals should require no maintenance by the customer.
Monochromated X-Ray Source with XR5 Electron Gun
Monochromator and XR5 (HA600054) Issue 5
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5.9 Fault Finding
Symptom General
Cause
Specific
Cause
How to Rectify How to Fix
Mains / re-
circulated water
supply switched off.
Booster pump will make
excessive noise. Check
supply.
Look for warning messages on
datasystem.
Switch on
supply.
Insufficient water
flow.
Warning
message on
datasystem.
Water flow not
sufficient to satisfy
flow requirement
Check inlet and outlet flow.
Look for warning messages on
datasystem.
Set pressure
flow
requirements as
specified in the
site preparation
guide.
Twin anode cover
not in place.
Check cover in position. Re-position
Mono anode cover
not in place.
Check cover in position. Re-position
Cover on anode
not in place,
tripping interlock.
Warning
message on
datasystem.
Mono anode lemo
connector not
connected
Check it is connected. Re-connect
The gun will
not start when
an attempt is
made to
switch on from
datasystem.
Cable not in
place, tripping
interlock.
Warning
message on
datasystem.
XR5 connector not
in place
Check connector in place. Re-connect
The gun trips out at 15KV.
Warning message on data system
relating to water impedance.
Water electrical
impedance too low.
Run at a 10KV mode and
observe the readback of the
leakage value in "Expert
Mode". The current should be
less than 20mA to avoid a trip,
so should be less than 12mA
at 10KV.
Replace
recirculator
water. Change
water supply.
Has not been
switched on.
Check on datasystem Switch onMono gun not
switched on
A HT tick has
corrupted the
power supply
settings.
Readback settings can be
seen in "Expert Mode", this
should follow the set values.
Stop and restart
mono gun.
A problem relating
to the analyser /
detection rather
than the mono gun.
Various Check for signal using another
source.
Fix as required.
Height of sample is
wrong.
Check height of sample on
CCD camera image.
Adjust height
Complete
loss of XPS
signal
Mono spots and
analysis position
not coincident.
Crystal
manipulators have
been moved.
Check that the position of the
mono spots coincident with the
CCD image using a phosphor
sample.
Adjust to obtain
coincident
position.

Monochromated X-Ray Source with XR5 Electron Gun
Issue 5 Monochromator and XR5 (HA600054)
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Symptom General
Cause
Specific
Cause
How to Rectify How to Fix
Height of sample is
slightly wrong
Check height of sample on
CCD camera image
Adjust heightMono spots or a
single spot not
completely
coincident. Crystal
manipulators have
been moved.
Check that the position of the
mono spots coincident with the
CCD image using a phosphor
sample.
Adjust to obtain
coincident
position.
Mono gun not
running at specified
settings.
A HT tick has
corrupted the
power supply
settings.
Readback settings can be
seen in "Expert Mode", this
should follow the set values.
Stop and restart
mono gun.
One mono spot(s)
blocked.
Twin anode not
retracted blocking
one spot.
Observe position of twin
anode.
Retract.
Partial loss
of XPS
signal
Anode coating degraded Move the anode on its z-drive
while running the ratemeter or
observing the spot on a
phosphor sample, look for
more signal or a brighter spot.
Leave at new
position.
Warning
messages
indicating a
gun fault
appear on
the data
system
Readback from
power supply to
datasystem
indicates a fault.
Can be caused by
a high voltage tick.
Check to see if it is was just a HT tick by clearing
the message and checking the gun still runs
correctly.
Loss of
control of
the gun from
the
datasystem.
Gun still
running
An HT tick has effected communication. Reboot the
datasystem. Try
the gun control
again.
Table 4: Fault Finding
5.10 Fuses Information – for Service Engineers
Within the digital X-ray PSU, T352/NT, there is an 800mA(T) fuse on the mains input.
Monochromated X-Ray Source with XR5 Electron Gun
Monochromator and XR5 (HA600054) Issue 5
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6 Index
A
Alignment of the Analysis Centre and Microscope
Cross Hairs .........................................................12
Anode ...................................................................9
Anode Cap Cleaning...........................................27
Anode Maintenance............................................21
Avantage Data System Monochromator Controls
............................................................................15
C
Cathode ................................................................9
Ceramic Replacement ........................................27
Contents ...............................................................2
Crystal Maintenance ...........................................27
D
Degassing - after a System Vent and Bake ........19
Description............................................................8
Different XR5 Operating Modes..........................16
E
Errors and Warnings...........................................16
F
Fault Finding.......................................................28
Figures..................................................................3
Fuses Information – for Service Engineers.........29
G
Getting Help..........................................................4
H
Health and Safety .................................................5
I
Index...................................................................30
Introduction ...................................................... 4, 8
L
Limits of Operation............................................. 18
M
Maintenance ...................................................... 19
Monochromator Crystal Assembly ..................... 10
Monochromator Fine Tuning .............................. 12
Monochromator Operation ................................. 15
Moving the XR5 Anode ...................................... 11
O
Observing the Monochromator Spot .................. 17
R
Re-alignment after a Bake ................................. 19
Replacing Anodes.............................................. 22
Replacing Filaments/Cathodes .......................... 23
S
Safety Interlocks .................................................. 5
Safety Warnings: ESSENTIAL READING............ 5
Switching on the Re-circulated Water ................ 17
T
T352/NT Computer-Controlled Power Supply.... 14
Tables .................................................................. 3
W
Water Cooling Circuit ......................................... 10
What You Should Have Already Read ................. 4
X
XR5 Electrostatic Electron Gun............................ 9