Surface Concept DLD6060-8S User manual

Delayline Detector
DLD6060-8S
(Release 1.10)
Manual

2Delayline Detector DLD6060-8S Manual | Surface Concept GmbH
Surface Concept GmbH
Am Sägewerk 23a
55124 Mainz
Germany
phone: [phone]
fax: [phone]
email: [e-mail]
web: www.surface-concept.de
All rights reserved. No part of this manual may
be reproduced without the prior permission
of Surface Concept GmbH.
Manual for the Delayline Detector
DLD6060-8S
Release 1.10
Manual Version 2.2
Printed on 2019-08-16

3
Delayline Detector DLD6060-8S Manual
Delayline Detector DLD6060-8S Manual | Surface Concept GmbH
1 Table of Contents
1 Table of Contents ...............................................................................................................................................3
2 Introduction......................................................................................................................................................... 6
2.1 General Information................................................................................................................................... 6
2.2 Safety Instructions ......................................................................................................................................6
2.3 General Overview of the System...........................................................................................................7
3 Installation............................................................................................................................................................8
3.1 Initial Inspection..........................................................................................................................................8
3.2 Installation..................................................................................................................................................... 8
3.2.1 Mounting the Delayline Detector............................................................................................. 8
3.2.2 Detector Orientation.................................................................................................................. 10
3.2.3 Cabling and High Voltage......................................................................................................... 10
3.2.4 Recommended System Requirements ................................................................................ 13
4 Operation of the DLD.....................................................................................................................................14
4.1 Getting Started .........................................................................................................................................14
4.1.1 “Start Up“ Procedure....................................................................................................................14
4.1.2 Dark Count Rate Measurement...............................................................................................16
4.1.3 Standard DLD Measurement....................................................................................................16
4.2 Standard Operation Procedure...........................................................................................................17
4.3 Bake Out Procedure.................................................................................................................................18
5 DLD - Principle of Operation........................................................................................................................19
5.1 Basics of Delayline Detection...............................................................................................................19
5.2 Basic Operational Modes of the Delayline Detector ...................................................................20
5.2.1 2D(x, y) Area Detection...............................................................................................................20
5.2.2 3D(x, y, t) Time Resolved Imaging...........................................................................................20
5.2.3 Specialities of the 8S Detector Anode ..................................................................................20
5.3 Data Acquisition .......................................................................................................................................21
5.4 Working with the DLD - Important Details .....................................................................................21
5.5 MCP Outgassing during Operation ...................................................................................................23

4Delayline Detector DLD6060-8S Manual | Surface Concept GmbH
6 Delayline Detector Layout............................................................................................................................24
6.1 Delayline Detector - Vacuum Wiring .................................................................................................24
6.2 Delayline Detector - Connection Ports.............................................................................................25
7 Pulse Processing Electronics........................................................................................................................27
7.1 Pulse Processing Electronics ACU 5.16.1..........................................................................................27
7.1.1 Positions of the Discriminator Threshold Regulators ......................................................28
8 Microchannel Plate .........................................................................................................................................29
8.1 Specications.............................................................................................................................................29
8.2 Storage.........................................................................................................................................................29
8.3 Handling......................................................................................................................................................29
8.4 Operation....................................................................................................................................................30
8.5 MCP Lifetime and Operation Voltage ...............................................................................................30
8.6 MCP Degase Procedure..........................................................................................................................33
8.7 Replacement..............................................................................................................................................33
9 Troubleshooting................................................................................................................................................34
10 Technical Data..................................................................................................................................................35
11 List of Figure.....................................................................................................................................................36

5
Delayline Detector DLD6060-8S Manual
Delayline Detector DLD6060-8S Manual | Surface Concept GmbH

6Delayline Detector DLD6060-8S Manual | Surface Concept GmbH
2 Introduction
2.1 General Information
This manual is intended to assist users in the installation, operation and maintenance of Release 1.10 of
the Delayline Detector DLD6060-8S as part of the PHOIBOS Hemispherical Analyzer Series. It is divided into
11 chapters. The chapter “Introduction” contains a brief description of the DLD. The chapter “Installation”
refers to installation and cabling. Further chapters explain the theory of the DLD, the technical details of
the detector readout package and the operation of the DLD.
2.2 Safety Instructions
Please read this manual carefully before performing any electrical or electronic
operations. Please also consult the “SURFACE CONCEPT Safety Instructions” and the
manual of the PHOIBOS Hemispherical Analyzer Series respectively, before using this
device. Strictly follow the safety rules given within each of the manuals.
The following symbols appear throughout the manual:
Note
The “note symbol” marks text passages, which contain important information/ hints
about the operation of the detector. Follow these information to ensure a proper
functioning of the detector.
The “caution symbol” marks warnings, which are given to prevent an accidentally
damaging of the detector or the readout system. Do NOT ignore these warnings and
follow them strictly. Otherwise no guarantee is given for arose damages.

7
Delayline Detector DLD6060-8S Manual
Delayline Detector DLD6060-8S Manual | Surface Concept GmbH
2.3 General Overview of the System
The Surface Concept Delayline Detectors are particularly developed for the needs of 1D(x), 2D(x,t), 2D(x,y)
or 3D(x,y,t) area and time detection of electrons, ions, x-ray and UV-light.
The layout of the DLD6060-8S detector has been specially designed for the detection of multi hit events
with the PHOIBOS 150/225 Analyzer. For the PHOIBOS Analyzer Series, the standard Channeltron Detector,
the CCD Imaging Detector, and the Delayline Detector can be used without any physical modication to
the analyzer (“plug and play”).
The DLD6060-8S consists of a chevron microchannel plate stack and dierent layers of segmented meander
structured delaylines. The image is sampled by the DLD readout electronics. The 3D (x, y, t) detection bases
on the measurement of time dierences and time sums of signals, with a high temporal resolution in one
device. The count rate can reach several MHz in the commonly used 4-fold coincidence measurement.
Typical applications for a Delayline Detector are for example: Fermi surface mapping, band mapping,
photoelectron diraction measurements, and similar angular dispersion experiments as well as XPS, UPS,
ESCA and AES and time resolved stroboscopic experiments.

8Delayline Detector DLD6060-8S Manual | Surface Concept GmbH
3 Installation
3.1 Initial Inspection
3.2 Installation
3.2.1 Mounting the Delayline Detector
Visual inspection of the system is required to ensure that no damage has occurred during shipping.
Should there be any signs of damage, please contact your provider immediately. Please check the delivery
according to the packing list (see Table 1) for completeness.
• Delayline Detector Unit (delivered in a vacuum container)
• Pulse Processing Unit ACU
• 4 x DLD Readout Cable (HDMI)
• CD with Documentation and Software
Table 1: Packing list for the DLD6060-8S Detector.
Note
The vacuum container of the Delayline Detector must be stored for later use. Replacement
will be done by shipping the detector/MCPs within this container. It can also be used to
store the detector when not installed in a vacuum chamber.
The detector is transported under vacuum. Proceed as follows, to install it into your vacuum chamber:
• Vent the transport container carefully with N2.
• Release the M8 screws of the vacuum container and pull out the detector carefully.
• Before installing the detector to your chamber, check the front side of the MCP stack for particles.
The microchannel plates in front of the detector should be protected from exposure
to particle contamination. Particles that stick to the plate can be removed by using a
single-hair brush carefully and/or with dry nitrogen. Reading the instructions “micro-
channel plates” in Chapter 8 is strongly recommended.

9
Delayline Detector DLD6060-8S Manual
Delayline Detector DLD6060-8S Manual | Surface Concept GmbH
• In most cases the detector head is stabilized again vibrations by a PTFE inlet within the transport
container to protect the detector head during transportation. In some cases the detector head might
still be stabilized by three transportation locks in the lower aluminum ring.
Remove the three M3 screws transportation locks (where applicable) before mounting
the Delayline Detector (see Figure 1). Otherwise the analyzer can be seriously damaged.
Figure 1: Removal of the transportation locks.
• When looking into the opened detector ange of the spectrometer from the bottom side, you can
locate the “alignment hole” for the detector. Align the pin in the cover of the Delayline Detector with
the corresponding hole in the ground plate (see Figure 2).
• Be sure that the detector is nearly parallel to the ground plate and push the detector carefully into its
seat.
• While pressing the detector into its seat, make sure that the distance between the two anges is approx.
4 mm before you feel that the springs are being compressed.
• Hold the detector in its position and tighten the anges with the M8 screws together.
Figure 2: Orientation pin in DLD cover (for illustration only) and corresponding hole in the ground plate of a PHOIBOS Analyzer.

10 Delayline Detector DLD6060-8S Manual | Surface Concept GmbH
• Install the detector into your vacuum chamber.
• Keep the vacuum container in case that the detector must be sent back for repair. It can also be used to
store the detector when not installed in a vacuum chamber.
Note
• The red dot in Figure 3 marks the 0/0 positions of the two DLD images (0° and 45° system). The 0/0
position of the 0° corresponds to the upper left corner of the image in the software.
Figure 3: 0/0 position of the DLD image (red dot) for the a) 0° system and b) 45° system.
The detector should be kept under vacuum all the time.
3.2.2 Detector Orientation
3.2.3 Cabling and High Voltage
• The general connection scheme of the Delayline Detector including its readout package is shown in
Figure 4.
Image 0/0 position
Orientation pin in DLD cover
a)
Image 0/0 position
Orientation pin in DLD cover
b)

11
Delayline Detector DLD6060-8S Manual
Delayline Detector DLD6060-8S Manual | Surface Concept GmbH
a)
b)
Figure 4: Connection scheme of a) the Delayline Detector to the PHOIBOS Analyzer and the SPECS Power Supply, b) the
DLD6060-8S and its readout package.

12 Delayline Detector DLD6060-8S Manual | Surface Concept GmbH
• The pulse processing unit ACU can be connected directly to the DLD 16-fold SMB feedthrough. The
metal pin gives the orientation. Fix the ACU with the two clips on the housing to the fastening bolds
on the feedthrough.
Hold the ACU straight and plug it very carefully.
The middle pins of the SMB connectors in the 16-fold SMB feedthrough can be damaged
when holding the ACU not straight while plugging.
• Use the DLD readout cables to connect the “Lines Out” sockets on the front of the ACU with the “TDC
Input” sockets at the rear panel of the TDC (see the TDC manual for specic connection scheme of the
TDC).
• The DLD6060-8S carries 3 SHV feedthroughs directly on the CF160 base ange. The three voltages are
named “CH-B”, “CH-HV” and “U_DLD”. The naming can be found directly engraved on the base ange.
“CH-B”is the contact to the front side of the MCP stack, while “CH-HV” is connected to the back side of
the MCP stack and “U_DLD” is connected to the detector anode.
Be sure that all voltages are settled to zero before connecting the high voltage cables to
the detector, otherwise serious damage to the detector can occur due to high voltage
sparks.
• Connect the output of your high voltage power supply to the“CH-B”, “CH-HV”and “U_DLD” connection
of the detector.
• Further information about detector operation voltages can be found in Chapter 4.
• Install the hardware drivers and the GUI – DLD software. See the GUI – DLD Software Installation manual
for further details.
• Connect the power cable to the main connector of the TDC and use the USB cable to connect the TDC
to the PC. Do not use PC front panel USB connectors; they are often restricted in performance.
• To perform time measurements with respect to an external clock, provide start pulses to the start
input of the TDC. Use the corresponding BNC socket of the TDC (see the TDC manual for the specic
connection scheme of the TDC).
Note
HV power supplies always produce some noise level on the HV lines. An increased
noise level can lead to a signicant loss of spatial and time resolution. In such a case an
appropriate noise lter between the HV power supply and the DLD HV connectors is
highly recommended. HV power supplies as part of the DLD delivery have been explicitly
tested for the DLD operation.

13
Delayline Detector DLD6060-8S Manual
Delayline Detector DLD6060-8S Manual | Surface Concept GmbH
All operation functions for data readout of the detector package are encapsulated in a dynamic linked
library (either“delayline_gpx3.dll”or scTDC1.dll). Data processing and presentation on the PC is realized by
an end-user software (e.g. GUI). See the corresponding software manual for detailed information on the
software package and the DLL interface.
The delivery package of the Delayline Detector includes a CD-ROM with hardware drivers and the GUI
software. Insert the CD into your disk drive and install the software package as described in the DLD - GUI
Software Installation Manual.
Read-out of the Delayline Detector is done via the USB port of the TDC (Time-to-Digital Converter). The
specic PC system requirements can be found in the corresponding TDC manual.
3.2.4 Recommended System Requirements

14 Delayline Detector DLD6060-8S Manual | Surface Concept GmbH
4 Operation of the DLD
Mistakes, which lead to complete wrong measurement results, can happen very easily
while taking the Delayline Detector to operation. Therefore it is strongly advised to read
the following sections completely before taking the detector to operation and to strictly
follow all given advices within it.
All operation voltages for the detector are given within the detectors specication sheet.
Due to gain degradation it will become necessary to increase the operation voltage from
time to time. Please refer to Chapter 8.5 for detailed information.
4.1 Getting Started
Note
4.1.1 “Start Up“ Procedure
Follow this procedure when taken the detector to operation the rst time and after every venting.
• Finish the complete cabling as described in Chapter 3.
• Turn on the TDC.
• Start your end-user software (e.g. GUI software) and within this software the rate meter, if available. For
details see your end-user software manual.
• Be sure, that the vacuum pressure at the detector is remarkably below 1E-6mbar, otherwise the
microchannel plates might be damaged by a local discharging (in general: the lower the pressure, the
longer the lifetime of the MCPs).
• Turn o all sources for electrons, ions, light or X-rays that might hit the detector.
Ion gauges and ion pump are both sources for electrons and ions. Ion pumps can also
be a source for X-rays. They can produce so many particles/ X-rays that the detector is in
a complete overload, even when they are not facing the detector directly. This will wear
out the MCPs very fast. Turn o ion pumps and ion gauges before turning on the high
voltage of the detector.
• Turn on the high voltage carefully.The voltage increase should not exceed 400V per minute. A schematic
sketch on how to ramp the voltages during the “Start-Up” procedure is given in Figure 5. The starting
operation voltage is specied in the specication sheet of the detector.
• Watch the vacuum pressure while increasing the high voltage; turn the voltages back, if an unusual
increase is observed in the pressure (indicator for high voltage sparking).

15
Delayline Detector DLD6060-8S Manual
Delayline Detector DLD6060-8S Manual | Surface Concept GmbH
High voltage sparks may seriously damage the detector anode/ meander or the MCPs.
Observe the chamber pressure carefully every time the high voltage is turned on. Switch
o the high voltage immediately in case of a temporary pressure rise by an order of
magnitude or more. This indicates high voltage sparking.
Wait some time (up to 5 min.). Start the“Start-Up”procedure again with an increased ramp
time. Turn o the high voltage completely, stop the procedure and call your provider for
further assistance, if is it not possible to reach the operation voltage without sparking.
Figure 5: Schematic sketch on voltage ramping during“Start-Up”procedure. See the SPECS Analyzer manual for ramping of the Herzog Potential.
Note
The detector starting operation voltage for “CH-HV” is given in the specication sheet.
The voltage for “U_DLD” is xed to “CH-HV” + 400V, when using the Surface Concept
HV Power Supply. It cannot be changed by the user and is therefore always increasing/
decreasing together with the voltage for“CH-HV”. This might not be the case for dierent
used HV supplies.
The voltage for “CH-HV” is always given in reference to the MCP front voltage “CH-B
(which corresponds to the external reference voltage of the Surface Concept HV Power
Supply). Depending on the detector setup the voltage dierence between “U_DLD” and
“CH-HV” can be dierent than 400V.

16 Delayline Detector DLD6060-8S Manual | Surface Concept GmbH
4.1.2 Dark Count Rate Measurement
• Check the detector output by means of your end-user software (e.g. GUI software) after ramping to the
operation voltage (the use of the rate meter where available is recommended).
• The dark count rate without any source should be as given in the specication sheet.
• Accumulate the dark counts for several minutes. The DLD image should appear homogeneous and
sharply bounded (see Figure 6 for an example).
Figure 6: Example for DLD image of accumulated dark counts.
4.1.3 Standard DLD Measurement
Note
• After nishing the dark count rate measurement with a satisfying result, you may now start carefully
with an electron or light source observing the detector output.
Example: The bias voltage U_Bias should always be set to 0V. Therefore the “CH-B” voltage is only dened
by the Herzog Potential, which must be ramped rst (see SPECS Analyzer manual for details). The “CH-HV”
voltage is given in respect to the“CH-B”voltage. A ramp time of about 5min. should be used to change the
“CH-HV” voltage from 0V to a target voltage of exemplary +1800V. The“U_DLD” voltage is given in respect
to the“CH-HV” voltage and should be changed after the “CH-HV” voltage has been set.
The analogue readout electronics has been adjusted to optimized detector voltages.
The starting operation voltages are given in the specication sheet of the detector.
Please note that one cannot compensate a voltage lower than the specied operation
voltages by increasing the intensity to the detector. This will only lead to complete false
measurement results.
It is highly recommended to keep the U_Bias at 0V. Contact your provider before changing
the bias voltage.
Keep in mind the description about the important operation details in Chapter 5.

17
Delayline Detector DLD6060-8S Manual
Delayline Detector DLD6060-8S Manual | Surface Concept GmbH
Follow this procedure for all later operation starts, when the detector has already been operated in
vacuum and has not been vented in between.
• Finish the complete cabling as described in Chapter 3.
• Turn on the TDC.
• Start your end-user software (e.g. GUI software) and within this software the rate meter (if available).
For details see your end-user software manual.
• Be sure, that the vacuum pressure at the detector is remarkably below 1E-6mbar, otherwise the
microchannel plates might be damaged by a local discharging (in general: the lower the pressure, the
longer the lifetime of the MCPs).
• Turn o all sources for electrons, ions, light or X-rays that might hit the detector.
• Turn up the high voltage carefully and stepwise within 2 - 3minutes to the operation voltage. The
starting operation voltage is specied in the specication sheet of the detector.
• Watch the vacuum pressure while increasing the high voltage; turn the voltages back, if an unusual
increase is observed in the pressure (indicator for high voltage sparking).
4.2 Standard Operation Procedure
Note
• Now you may start carefully with an electron source observing the detector output.
Turn o the high voltage, close the software and turn o the TDC before performing any
changes of the cabling.
High voltage sparks may seriously damage the detector anode/ meander or the MCPs.
Observe the chamber pressure carefully every time the high voltage is turned on. Switch
o the high voltage immediately in case of a temporary pressure rise by an order of
magnitude or more. This indicates high voltage sparking.
Wait some time (up to 5 min.). Start the procedure again with an increased ramp time.
Turn o the high voltage completely, stop the procedure and call your provider for
further assistance, if is it not possible to reach the operation voltage without sparking.
Keep in mind the description about the important operation details in Chapter 5.
Turn o the high voltage, close the software and turn o the TDC before performing any
changes of the cabling.

18 Delayline Detector DLD6060-8S Manual | Surface Concept GmbH
4.3 Bake Out Procedure
Note
It is strongly advised to read the following sections completely before baking out the
detector and to strictly follow all given advices within it.
Please also read the bake out instructions in the main manual of the PHOIBOS Analyzer
before proceeding.
The maximum allowed temperature for the detector is 150°C. Do not exceed this
temperature.
After a bake out, the detector needs at least one day to cool down. If channel plates are
operated at higher temperatures (> 70°C) they can suer damage. Such channel plates
will lose gain and exhibit a markedly higher detector plateau.
Even if the detector housing feels just warm, any internal parts seated on insulators (e.g.
the detector anode) may still be too hot for safe operation. It is imperative that all users
be informed of this issue and take the necessary precaution to ensure proper device
operation.
• The detector electronics (ACU) must be removed before any bake out.
• Windows and feedthroughs should be wrapped with aluminum foil, to protect them from rapid
temperature changes.
• The use of heating tapes and jackets is not recommended, due to danger of local overheating.
• Do not remove the blankets until the entire system has thoroughly cooled o.
• Do not operate the detector before the temperature has returned to ambient conditions.

19
Delayline Detector DLD6060-8S Manual
Delayline Detector DLD6060-8S Manual | Surface Concept GmbH
5 DLD - Principle of Operation
5.1 Basics of Delayline Detection
The Delayline Detector (DLD) consists of a microchannel plate stack (required to amplify incoming
electrons) and the detector anode. The DLD anode (for 4 quadrant DLDs: each single quadrant) consists
basically of two meander structured delaylines; one rotated by 90° with respect to the other and both
isolated from each other. The electron cloud from the MCP stack output is drawn to the detector anode
by a positive potential dierence between anode and back side of MCP stack, where it induces electrical
pulses into the delayline by capacitive coupling. The pulses are traveling to the both ends of the meander
within a time determined by the hitting position.
Each hit position is encoded by a fast data acquisition unit, which also may detect the hit time referenced
to an external clock in repetitive (stroboscopic) experiments.
Delayline Detectors are single counting devices; therefore the complete device works linearly even
at extremely low numbers of incoming electrons. The maximum count rate in the 4-fold coincidence
measurement is up to a few million counts per second. The exact value depends on the individual DLD
layout (e.g. the size of the active area) and is given within the specication sheet of the DLD.
Figure 7: Schematic drawing of the basic assembly of a Delayline Detector.

20 Delayline Detector DLD6060-8S Manual | Surface Concept GmbH
5.2 Basic Operational Modes of the Delayline Detector
5.2.1 2D(x, y) Area Detection
The arrival times of pulses per event at the 4 ends of the DLD meander/ quadrant are subtracted in order
to determine a position in x and y (x: tx1-tx2; y: ty1-ty2). The 4 TDC stop signals are grouped internally in
pairs to form the x- and y-coordinates. All DLD software adjustments are done by the end-user software
according to the user’s chosen parameters.
5.2.2 3D(x, y, t) Time Resolved Imaging
The Delayline Detector may measure all events in temporal reference to an external clock. For this mode,
the user needs to start the TDC by an external clock, providing a low jitter LVTTL signal to the start input
of the TDC.
Time measurements are performed by summing up the arrival times of pulses at the end of the DLD
meanders, i.e. the same results which are used to determine positions for each event are summed. It is
possible to sum only tx1 and tx2 (tsumx) or ty1 and ty2 (tsumy), because both sums should carry the same
temporal information of a time related experiment. The total sum t(DLD) of all four time measurements
(tx1, tx2, ty1, ty2) may be a good choice as well. The results of all those time sums correspond to t(sum)
= t(oset) + t(hit), where t(hit) is the interesting time (e.g. ToF) in a given experiment and t(oset) is a
device related constant, which depends on cable lengths, electronics propagation times, experimental
setup etc. Therefore, it is possible to completely determine position and time of each event from only 4
precise time measurements. The software can group all measured time sums in plain 1D time histograms,
which are valid for the chosen region of interest (ROI) with the correct time bin unit. The time bin unit
for each single readout channel is around 27ps, but due to the calculation of the tsums and t(DLD), the
time axis is expanded virtually (simplied expression). Therefore the channel width in the 1D histogram
is dierent for the tsumx, tsumy and t(DLD) histograms. The correct value for a current setting is always
shown by the software. The t(DLD) signature can be used in order to setup the regions of interest in time
for measurements of time resolved images. The software is able to sample 3D histograms as image stacks
in time, where each image corresponds to one channel width of the t(DLD) time histogram.
5.2.3 Specialties of the 8S Detector Anode
The anode of an 8S Delayline Detector diers by a special segmentation of the meander system as well as
by a second, rotated meander system.
In opposite to a single Delayline Detector anode consisting of a single meander for the x and for the y
direction, the 8S anode has two seperated meanders for each direction x and y.
In addition it has a complete second set of x and y meanders, rotated by 45° (R) anticlockwise in respect to
the normal 0° system (N). Detailed information of the meander segmentation and orientation is given in
Chapter 6.