Agilent Technologies Cryogenic User manual

Agilent Technologies
Cryogenic Systems
Operation
User Guide

Notices
© Agilent Technologies, Inc. 2011
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Manual Part Number
91-002699-00A
Edition
First edition, August 2011
Printed in USA
Agilent Technologies, Inc.
5301 Stevens Creek Boulevard
Santa Clara, CA 95051 USA
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Safety Notices
CAUTION
A CAUTION notice denotes a
hazard. It calls attention to an oper-
ating procedure, practice, or the
like that, if not correctly performed
or adhered to, could result in
damage to the product or loss of
important data. Do not proceed
beyond a CAUTION notice until the
indicated conditions are fully
understood and met.
WARNING
A WARNING notice denotes a
hazard. It calls attention to an
operating procedure, practice, or
the like that, if not correctly per-
formed or adhered to, could result
in personal injury or death. Do not
proceed beyond a WARNING
notice until the indicated condi-
tions are fully understood and met.

Cryogenic Systems Operation 3
Contents
1 Introduction
Safety 8
Warning notices 8
Caution notices 11
Radio-frequency emission regulations 12
Agilent Cold Probes 13
Closed-Cycle Cryogenic System 14
CryoBay (cryogenics bay) 14
He compressor 15
Document of Certification 16
2 Cryogenic Operation
Preparing for Cryogenic Operation 18
Connect the CCC transfer arm (stinger) to the probe 18
Connect the vacuum system to the probe vacuum chamber 22
Final System Checks, Cautions and Warnings 23
Configuring VnmrJ for Cryogenic Operation 25
Starting Cryogenic Operation 26
Start the cryogenic process as follows: 26
Stopping Cryobay Operations 28
Cryobay monitor functions 28
Warming both the CCC and the probe 28
Disconnecting the Agilent Cold Probe from the CryoBay 30
Vent the cryogenic transfer line 30
Disconnecting the Agilent Cold Probe from the CryoBay 31
Removing the Agilent Cold Probe from the Magnet 33
Removing the Agilent Cold Probe from magnet when <285 K 35
Agilent Cold Probe/Cryogenic System Care When Not in Use 37
Agilent Cold Probe will remain attached to the CryoBay 37
Agilent Cold Probe disconnected from the CryoBay 39
3 Maintenance and Service
Preventative Maintenance and Service Intervals 42
Changing the Helium Gas Supply (Compressed Gas Cylinder) 43
Filling the Helium Compressor 44

4Cryogenic Systems Operation
Turbo Pump Operation 46
Compressor Maintenance 46
Closed-Cycle Chiller (CCC) Maintenance 47
Changing Cooling-Water Filters (Water-Cooled Compressor) 47
Cooling-water requirements 47
Changing cooling-water filters 47
4 Principles of Operation
Cryogenic System Components 50
Principles of Operation 51
External CryoBay Controls and Connections 54
Internal CryoBay Assemblies 55
Operation Cycle, Status Messages, and States 55
Idle 55
Start 57
Stop 58
Detach 58
Vacuum purge 59
Pump probe 59
5 CryoBay Monitor
Opening the CryoBay Monitor (Main Window) 64
VnmrJ 64
Vertical panel - view menu 66
Stand-alone CryoBay control computer 67
CryoBay Controls Window 68
CryoBay Controls - Loading Files 70
CryoBay Controls – Advanced 73
CryoBay Data Log 74
VnmrJ 74
Stand-alone CryoBay control computer 74
Data log sequence of readings displayed 74
CryoBay Controls–Help Menu 75
About CryoBay 76
Service counter 76
About panel 76

Cryogenic Systems Operation 5
6 Error Messages
Fault Codes 78
CryoBay Actions Under Fault Conditions 80
General Operation Faults 81
Start window - cannot start. System not warm 81
Detach probe window - detach probe failed 81
Fault Code Causes, Actions and Corrections 82
7 Unexpected Events
Advanced Notice of Utility Shutdown 92
Single-Phase Power Failure 93
Three-Phase Power Failure (Compressor) 94
Cooling-Water Failure (Water-Cooled Compressor) 94
Compressed Air for Pneumatics Failure 95
Vacuum 95
Purging 95
Cooling or operating 95
Temperature Controller Gas Failure 95
Alternative gas source is available 95
Alternative gas source is not available 95
Host Computer Failure 96
Recovering from an Unexpected Event 97
CCC has not reached room temperature (285 K) 97
CCC has reached room temperature 98
Safety Shutdown 99
Sources of power 99
Safety shutdown of the system 99
Powering system back on after safety shutdown 101
8 Appendix
CryoBay Sample Eject Air and Sample Catcher 104
Turning on or off the CryoBay sample eject air 105
Adjusting the CryoBay sample eject air 107
Inserting a sample using a sample catcher 109
Ejecting and removing a sample using a sample catcher 109
Swagelok and Aeroquip Fittings 110
Swagelok connector installation 110
Retightening swagelok connectors 111

6Cryogenic Systems Operation
Aereoquip connectors 112
Connecting to helium compressor and CCC 113
Disconnecting from helium compressor 113

7
Cryogenic Systems Operation
User Guide
Agilent Technologies
1
Introduction
A Cryogenic system consists of an Agilent Cold Probe and
closed- cycle cryogenic system.
The cryogenic system circulates cold He gas to maintain key
probe components at an operating temperature of
approximately 25 kelvin.
Safety 8
Agilent Cold Probes 13
Closed-Cycle Cryogenic System 14

8Cryogenic Systems Operation
1Introduction
Safety
Warning notices
Observe the following precautions during installation,
operation, maintenance, and repair of the instrument.
Failure to comply with these warnings, or with specific
warnings elsewhere in Agilent manuals, violates safety
standards of design, manufacture, and intended use of the
instrument. Agilent assumes no liability for customer failure
to comply with these precautions.
The superconducting magnet system generates strong
magnetic fields that can affect operation of some cardiac
pacemakers or harm implanted or attached devices such as
prosthetic parts and metal blood vessel clips and clamps.
Pacemaker wearers should consult the user manual provided
by the pacemaker manufacturer or contact the pacemaker
manufacturer to determine the effect on a specific
pacemaker. Pacemaker wearers should also always notify
their physician and discuss the health risks of being in
proximity to magnetic fields. Wearers of metal prosthetics
and implants should contact their physician to determine if
a danger exists.
Refer to the manuals supplied with the magnet for the size
of a typical 5- gauss stray field. This gauss level should be
checked after the magnet is installed.
The strong magnetic field surrounding the magnet attracts
objects containing steel, iron, or other ferromagnetic
materials, which includes most ordinary tools, electronic
equipment, compressed gas cylinders, steel chairs, and steel
carts. Unless restrained, such objects can suddenly fly
towards the magnet, causing possible personal injury and
extensive damage to the probe, dewar, and superconducting
WARNING
Persons with implanted or attached medical devices such as
pacemakers and prosthetic parts must remain outside the 5-gauss
perimeter from the centerline of the magnet.
WARNING
Keep metal objects outside the 10-gauss perimeter from the
centerline of the magnet.

Introduction 1
Cryogenic Systems Operation 9
solenoid. The greater the mass of the object, the more the
magnet attracts the object.
Only nonferromagnetic materials such as plastics, aluminum,
wood, and nonmagnetic stainless steel, should be used in the
area around the magnet. If an object is stuck to the magnet
surface and cannot easily be removed by hand, contact
Agilent service for assistance.
Refer to the manuals supplied with the magnet for the size
of a typical 10- gauss stray field. This gauss level should be
checked after the magnet is installed.
Dangerous high voltages that can kill or injure exist inside
the instrument. Before working inside a cabinet, turn off the
main system power or unplug the unit.
Any unauthorized modification could injure personnel or
damage equipment and potentially terminate the warranty
agreements or service contract. Written authorization
approved by an Agilent product manager is required to
implement any changes to the hardware of a NMR
spectrometer. Maintain safety features by referring system
service to an Agilent service office.
Operation with flammable gases or fumes present creates the
risk of injury or death from toxic fumes, explosion, or fire.
If the magnet dewar should quench (sudden appearance of
WARNING
Only qualified maintenance personnel shall remove equipment
covers or make internal adjustments.
WARNING
Do not substitute parts or modify the instrument.
WARNING
Do not operate in the presence of flammable gases or fumes.
WARNING
Leave area immediately in the event of a magnet quench.

10 Cryogenic Systems Operation
1Introduction
gasses from the top of the dewar), leave the area
immediately. Sudden release of helium or nitrogen gases can
rapidly displace oxygen in an enclosed space creating a
possibility of asphyxiation. Do not return until the oxygen
level returns to normal.
In contact with the body, helium and nitrogen can cause an
injury similar to a burn. Never place your head over the
helium and nitrogen exit tubes on top of the magnet. If
helium or nitrogen contacts the body, seek immediate
medical attention, especially if the skin is blistered or the
eyes are affected.
Unless the probe is removed from the magnet, never look
down the upper barrel. You could be injured by the sample
tube as it ejects pneumatically from the probe.
A sample tube subjected to a change in temperature can
build up excessive pressure, which can break the sample
tube glass and cause injury by flying glass and toxic
materials. To avoid this hazard, establish the freezing and
boiling point of a sample before doing a variable temperature
experiment.
The magnet dewar has a high center of gravity and could tip
over in an earthquake or after being struck by a large object,
injuring personnel and causing sudden, dangerous release of
nitrogen and helium gasses from the dewar. Therefore, the
WARNING
Avoid helium or nitrogen contact with any part of the body.
WARNING
Do not look down the upper barrel.
WARNING
Do not exceed the boiling or freezing point of a sample during
variable temperature experiments.
WARNING
Support the magnet and prevent it from tipping over.

Introduction 1
Cryogenic Systems Operation 11
magnet must be supported by at least one of two methods:
with ropes suspended from the ceiling or with the
antivibration legs bolted to the floor. Refer to the
Installation Planning Manual for details.
The relief valves prevent air from entering the nitrogen and
helium vent tubes. Air that enters the magnet contains
moisture that can freeze, causing blockage of the vent tubes
and possibly extensive damage to the magnet. It could also
cause a sudden dangerous release of nitrogen and helium
gases from the dewar. Except when transferring nitrogen or
helium, be certain that the relief valves are secured on the
vent tubes.
Caution notices
Observe the following precautions during installation,
operation, maintenance, and repair of the instrument.
Failure to comply with these cautions, or with specific
cautions elsewhere in Agilent manuals, violates safety
standards of design, manufacture, and intended use of the
instrument. Agilent assumes no liability for customer failure
to comply with these precautions.
The strong magnetic field surrounding a superconducting
magnet can erase magnetic media such as floppy disks and
tapes. The field can also damage the strip of magnetic media
found on credit cards, automatic teller machine (ATM) cards,
and similar plastic cards. Many wrist and pocket watches are
also susceptible to damage from intense magnetism.
Refer to the manuals supplied with the magnet for the size
of a typical 5- gauss stray field. This gauss level should be
checked after the magnet is installed.
WARNING
Do not remove the relief valves on the vent tubes.
CAUTION
Keep magnetic media, ATM and credit cards, and watches outside
the 5-gauss perimeter from the centerline of the magnet.
CAUTION
Check helium and nitrogen gas flow meters daily.

12 Cryogenic Systems Operation
1Introduction
Record the readings to establish the operating level. The
readings will vary somewhat because of changes in
barometric pressure from weather fronts. If the readings for
either gas should change abruptly, contact qualified
maintenance personnel. Failure to correct the cause of
abnormal readings could result in extensive equipment
damage.
Wear grounded antistatic wristband or equivalent before
touching any parts inside the doors and covers of the
spectrometer system. Also, take ESD precautions when
working near the exposed cable connectors on the back of
the console.
Radio-frequency emission regulations
The covers on the instrument form a barrier to
radio- frequency (RF) energy. Removing any of the covers or
modifying the instrument may lead to increased
susceptibility to RF interference within the instrument and
may increase the RF energy transmitted by the instrument in
violation of regulations covering RF emissions. It is the
operator’s responsibility to maintain the instrument in a
condition that does not violate RF emission requirements.
CAUTION
Take electrostatic discharge (ESD) precautions to avoid damage to
sensitive electronic components.

Introduction 1
Cryogenic Systems Operation 13
Agilent Cold Probes
Agilent Cold Probes, Figure 1, achieve significant gains in
sensitivity through the application of advanced cryogenic
technologies for cooling key probe components.
Figure 1 Agilent Cold Probes

14 Cryogenic Systems Operation
1Introduction
Closed-Cycle Cryogenic System
The Agilent Closed- Cycle Cryogenic System, Figure 2, is
designed for continuous long- term operation. During normal
operations, the system does not consume or require
additional He after initial setup. Routine service operations
utilize some He gas.
The system cools the probe components to their operating
temperature in about 4 hours. Optimal performance is
realized when the system is allowed to stabilize overnight.
The Closed- Cycle Cryogenic system consists of the following
units:
CryoBay (cryogenics bay)
•Closed- cycle chiller (CCC) or helium (He) refrigerator
The CCC supplies cold He gas to the cryogenic heat
exchanger inside the Agilent Cold Probe.
•Valve Box / Control Board
Figure 2 Agilent Cold Probe and cryogenic system

Introduction 1
Cryogenic Systems Operation 15
The valve box and control board automates all routine
cryogenic operations.
•Temperature Controller
The temperature controller regulates the temperature of
the cold head inside the Agilent Cold Probe.
•Vacuum System
The vacuum system automatically pumps down the
cryogenic system and the probe. The vacuum system is
connected to the probe's vacuum pump- out port using a
flexible pumping line.
•The turbo pump operates while the probe is warm and
during cooling and warming of the system.
•The Ion Pump maintains the vacuum while the system
is operational.
•The Vacuum Thermocouple Gauge is used to monitor
the system vacuum level.
He compressor
Provides high- pressure He gas to the CCC.
The CryoBay is illustrated in Figure 3.
Figure 3 CryoBay

16 Cryogenic Systems Operation
1Introduction

17
Cryogenic Systems Operation
User Guide
Agilent Technologies
2
Cryogenic Operation
Preparing for Cryogenic Operation 18
Final System Checks, Cautions and Warnings 24
Configuring VnmrJ for Cryogenic Operation 26
Starting Cryogenic Operation 28
Stopping Cryobay Operations 30
Disconnecting the Agilent Cold Probe from the CryoBay 32
Removing the Agilent Cold Probe from the Magnet 35
Agilent Cold Probe/Cryogenic System Care When Not in Use 39

18 Cryogenic Systems Operation
2Cryogenic Operation
Preparing for Cryogenic Operation
The Agilent Cold Probe must have all pneumatics attached
and electrical cables connected in preparation for running
NMR experiments. If multiple Agilent Cold Probes are on the
system, the correct temperature control calibration must be
loaded (see “CryoBay Controls - Loading Files” on page 72).
Refer to the Agilent Cold Probe Installation manual before
continuing.
The Agilent Cold Probe may be cooled outside of the magnet,
using an optional removable probe accessory, allowing the
probe to be inserted into the magnet at a later point in time.
Connect the CCC transfer arm (stinger) to the probe
1Verify that the side arm of the probe is firmly clamped
to the magnet using the side- arm support provided.
2Slide the protective sleeve from the CCC bayonet fitting.
3Inspect and, if necessary, replace or correct the following:
•Inspect the probe side- arm's inner O- rings to be sure
that they are properly seated in their grooves and that
they are not damaged or cracked. Damaged or missing
O- rings can be replaced with Viton #114 replacements,
which are available from Agilent Inc. or local
distributors. Lightly vacuum grease the O- rings before
re- installing.
•Inspect the stinger of the cryogenic transfer line for
dirt, moisture, or other foreign material; clean if
necessary.
•Inspect the plastic bushing and replace it if it is
deformed (the curved face is toward the probe). If it is
missing, it may be lodged inside the cryogenic arm of
the probe.
CAUTION
The transfer arm and vacuum line attachment to the Agilent Cold
Probe make it difficult to insert the probe into the magnet. Take
appropriate precautions to prevent accidental damage, including the
assistance of another person. For normal operation, begin
preparation for cryogenic operations with the Agilent Cold Probe at
room temperature in the magnet.

Cryogenic Operation 2
Cryogenic Systems Operation 19
•Inspect the interior of the cryogenic arm of the probe
for foreign objects and extra bushings. Remove any
foreign materials and bushings.
•Verify that the brass stinger tip is screwed on tightly
and is not loose.
4Install the plastic bushing on the stinger with the flat
face towards the CryoBay (curved face towards the
stinger tip).
5Install the rippled plastic sleeve over the stinger, as seen
in Figure 4. The sleeve may remain inside the probe after
first use.
6Position the flexible cryogenic transfer line, as seen in
Figure 5, of the refrigerator assembly in line with the
probe side arm in preparation for insertion of the stinger
into the probe side arm.
Figure 4 CCC Stinger with plastic bushing and plastic sleeve
Plastic Sleeve Plastic Bushing

20 Cryogenic Systems Operation
2Cryogenic Operation
7Slide the flexible cryogenic transfer line into the probe
side arm until the coupling is well seated.
If the coupling does not seat properly, extract the
transfer line and inspect the cryogenic arm and stinger
for multiple plastic bushings. Remove the extra bushing
and repeat the installation.
8Insert sidearm bayonet into the probe cryostat side- arm
coupling nut, as seen in Figure 6.
9Engage guide pin fully in slot as shown. If necessary,
turn the slotted nut a few turns in the direction of the
arrow before engaging.
10 Tighten the slotted nut, turning it in the opposite
direction of the arrow.
Keep the pins fully engaged as you do this, so that both
parts turn together. (During the cool- down process,
retighten the nut several times to take up thermal
contraction.)
11 Secure the flexible cryogenic transfer line and the
vacuum line to the vibration damping pier to support the
line, as seen in Figure 7. The orientation for following
the directions is facing the magnet.
Figure 5 Connect CryoBay to Agilent Cold Probe
Figure 6 Cryogenic arm connector