ORTEC MÖBIUS-PT, MÖBIUS-ST, MÖBIUS-B User Manual

ORTEC ®

MÖBIUS Recycler

Condensing Liquid Nitrogen

HPGe Detector Cooling System

User Manual

MÖBIUS-PT, MÖBIUS-ST, MÖBIUS-B

Printed in U.S.A. ORTEC® Part No. 805709 0514
Manual Revision L

™

ORTEC ® MÖBIUS™ Recycler HPGe Detector Cooling System 805709F / 1115

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PROPERTY OF AMETEK, INC. – ORTEC®

Advanced Measurement Technology, Inc.

a/k/a/ ORTEC®, a subsidiary of AMETEK®, Inc.

WARRANTY

ORTEC* warrants that the items will be delivered free from defects in material or workmanship. ORTEC makes no other
warranties, express or implied, and specifically NO WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR
PURPOSE.

ORTEC’s exclusive liability is limited to repairing or replacing at ORTEC’s option, items found by ORTEC to be defective in
workmanship or materials within two years from the date of delivery. ORTEC’s liability on any claim of any kind, including
negligence, loss, or damages arising out of, connected with, or from the performance or breach thereof, or from the
manufacture, sale, delivery, resale, repair, or use of any item or services covered by this agreement or purchase order, shall
in no case exceed the price allocable to the item or service furnished or any part thereof that gives rise to the claim. In the

event ORTEC fails to manufacture or deliver items called for in this agreement or purchase order, ORTEC’s exclusive liability
and buyer’s exclusive remedy shall be release of the buyer from the obligation to pay the purchase price. In no event shall

ORTEC be liable for special or consequential damages.

Quality Control

Before being approved for shipment, each ORTEC instrument must pass a stringent set of quality control tests designed to
expose any flaws in materials or workmanship. Permanent records of these tests are maintained for use in warranty repair
and as a source of statistical information for design improvements.

Repair Service

If it becomes necessary to return this instrument for repair, it is essential that Customer Services be contacted in advance of
its return so that a Return Authorization Number can be assigned to the unit. Also, ORTEC must be informed, either in writing,
by telephone [[phone]] or by facsimile transmission [[phone]], of the nature of the fault of the instrument being

returned and of the model, serial, and revision (“Rev” on rear panel) numbers. Failure to do so may cause unnecessary delays

in getting the unit repaired. The ORTEC standard procedure requires that instruments returned for repair pass the same quality
control tests that are used for new-production instruments. Instruments that are returned should be packed so that they will
withstand normal transit handling and must be shipped PREPAID via Air Parcel Post or United Parcel Service to the designated
ORTEC repair center. The address label and the package should include the Return Authorization Number assigned.
Instruments being returned that are damaged in transit due to inadequate packing will be repaired at the sender's expense,
and it will be the sender's responsibility to make claim with the shipper. Instruments not in warranty should follow the same
procedure and ORTEC will provide a quotation.

Damage in Transit

Shipments should be examined immediately upon receipt for evidence of external or concealed damage. The carrier making
delivery should be notified immediately of any such damage, since the carrier is normally liable for damage in shipment.
Packing materials, waybills, and other such documentation should be preserved in order to establish claims. After such
notification to the carrier, please notify ORTEC of the circumstances so that assistance can be provided in making damage
claims and in providing replacement equipment, if necessary.

Copyright © 2014, Advanced Measurement Technology, Inc. All rights reserved.
*ORTEC® is a registered trademark of Advanced Measurement Technology, Inc. All other trademarks used herein are the property of their

respective owners.
NOTICE OF PROPRIETARY PROPERTY — This document and the information contained in it are the proprietary property of AMETEK Inc.,

ORTEC Business Unit. It may not be copied or used in any manner nor may any of the information in or upon it be used for any purpose
without the express written consent of an authorized agent of AMETEK Inc., ORTEC Business Unit.

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PROPERTY OF AMETEK, INC. – ORTEC®

TABLE OF CONTENTS

1. INTRODUCTION ........................................................................................................................................................... 7

1.1. HOW MÖBIUS WORKS ..................................................................................................................................... 7

1.2. UPS INTEROPERABILITY .................................................................................................................................... 7

1.3. SPECIFICATIONS ............................................................................................................................................... 8

1.3.1. Performance ....................................................................................................................................... 8

1.3.2. Mechanical .......................................................................................................................................... 8

1.3.3. CE ........................................................................................................................................................ 9

1.4. INSPECTION FOR SHIPPING DAMAGE .............................................................................................................. 9

2. SYSTEM OVERVIEW ................................................................................................................................................... 10

2.1. CONTENTS OF THE SHIPPING CARTON........................................................................................................... 10

2.2. THE MÖBIUS ................................................................................................................................................... 10

2.3. PREPARING THE MÖBIUS FOR USE ................................................................................................................ 12

3. INSTALLATION ........................................................................................................................................................... 15

3.1. ASSEMBLING THE SYSTEM ............................................................................................................................. 16

3.2. FILLING WITH LN2 .......................................................................................................................................... 17

3.3. SAFETY AND EQUIPMENT WARNINGS ........................................................................................................... 19

3.3.1. Liquid Nitrogen Safety ...................................................................................................................... 19

3.3.2. Other Precautions ............................................................................................................................. 20

3.3.2.1. HANDLING POPTOP DETECTOR/CRYOSTAT ASSEMBLIES ................................................................ 20

3.3.2.2. ELECTRICAL CAUTIONS ............................................................................................................ 20

3.3.2.3. UNINTENDED DETECTOR WARM-UP ......................................................................................... 21

4. MAINTENANCE ......................................................................................................................................................... 22

4.1. CLEANING OR REPLACING THE MÖBIUS FILTER ............................................................................................. 22

4.2. EMPTYING AND WARMING THE MÖBIUS ...................................................................................................... 23

4.3. TRANSPORTING OR SHIPPING THE MÖBIUS .................................................................................................. 24

4.4. DETECTOR WARM-UP .................................................................................................................................... 24

4.5. REMOVING THE DETECTOR/CRYOSTAT ASSEMBLY ........................................................................................ 24

4.6. DECOUPLING A POPTOP CAPSULE FROM THE CRYOSTAT ............................................................................. 25

ORTEC ® MÖBIUS™ Recycler HPGe Detector Cooling System 805709F / 1115

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PROPERTY OF AMETEK, INC. – ORTEC®

ADDITIONAL WARRANTY AND SAFETY NOTICES

There are no serviceable parts in or on the MÖBIUS except those specified in this manual, e.g., the mains power cord,
fuses, and filter. Opening the rear panel or otherwise accessing the interior components, attempting to detach the level
monitor or remote status display leads, or performing operations other than those described in this manual (e.g.,

inserting/removing the mechanical cooler’s protective foam block, adding/removing liquid nitrogen, and

inserting/withdrawing detector crystostats into/from the dewar) may void your warranty.

Using this equipment in a manner not specified in this manual may impair the protection the equipment provides.

Changes to valving, tubing, or other components of the MÖBIUS system can result in damage to equipment, injury,
or death. Modifications to any system components must be made in consultation with ORTEC technical support
personnel and authorized in writing in advance of such modifications.

SAFETY INSTRUCTIONS AND SYMBOLS

This manual contains up to three levels of safety instructions that must be observed in order to avoid personal injury
and/or damage to equipment or other property. These are:

DANGER Indicates a hazard that could result in death or serious bodily harm if the safety instruction is not observed.
WARNING Indicates a hazard that could result in bodily harm if the safety instruction is not observed.
CAUTION Indicates a hazard that could result in property damage if the safety instruction is not observed.

Please read all safety instructions carefully and make sure you understand them fully before attempting to use this
product.

In addition, the following symbol might appear on the product:

ATTENTION – Consult the manual in all cases where this symbol is marked in order to determine
the nature of the potential hazards and any actions that must be taken to avoid them

DANGER – Hazardous voltage

Protective earth (ground) terminal

Please read all safety instructions carefully and make sure you understand them fully before attempting to use this
product.

805709F / 1115 ORTEC ® MÖBIUS™ Recycler HPGe Detector Cooling System

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ORTEC ® MÖBIUS™ Recycler HPGe Detector Cooling System 805709F / 1115

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PROPERTY OF AMETEK, INC. – ORTEC®

MÖBIUS-B w/ HJ-style cryostat

MÖBIUS-B w/ PopTop® cryostat

MÖBIUS-PT w/ PopTop® cryostat

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ORTEC MÖBIUS™ RECYCLER

CONDENSING LIQUID NITROGEN HPGE DETECTOR COOLING SYSTEM

1. INTRODUCTION

The ORTEC MÖBIUS Recycler integrates a Sunpower® CryoTel® Stirling-cycle cryocooler with a specially designed 28 liter
liquid nitrogen (LN2) dewar to yield a high-reliability HPGe detector cooling system. This is especially useful for counting
laboratories that have periodic power failures. The MÖBIUS fits easily under standard lead shields with the same
footprint as a regular dewar. The remote status display can be mounted outside the lead shield for easy visibility.

A continuously operating MÖBIUS requires refilling only once every two (2) years — a major savings in worry, time,
money, and exposure to LN2 handling risks. During a power failure, the MÖBIUS performs as a standard dewar. After
power is restored, check the LN2 level and top it off if necessary — that’s all it takes to return the system to maximum
performance.

The MÖBIUS supports our Streamline and PopTop® detector lines, and horizontal as well as vertical dipstick-type
cryostats. In addition, a number of non-ORTEC cryostats and detectors are supported; contact your ORTEC
representative for more information. If you have purchased a detector in addition to a MÖBIUS, all detector-specific
information is included in the detector’s data sheet and user manual.

1.1. HOW MÖBIUS WORKS

The MÖBIUS has a computer-controlled pressure system that maintains a
constant and stable 0.5 psi (3.5 kPa) in the vapor space of the dewar. A
pressure transducer feeds the pressure in the dewar to the onboard
computer, which controls the rate at which the Sunpower cryocooler re­condenses the nitrogen vapor to liquid. The cryocooler operates only when a
cryostat is installed and the two fill/vent valves are closed (i.e., when the
system is pressurized). This evaporation/re-condensation process is
illustrated in Figure 1.

The fill collar has redundant pressure relief valves designed to open if the
pressure exceeds 1 psi (6.9 kPa). In the event of power loss the cryocooler
stops, the pressure inside the vapor space starts increasing, and nitrogen
vapor slowly begins escaping into the atmosphere via the pressure relief
valves. However, if power remains on and the system is operating in an
uninterrupted steady state, there is no LN2 loss and the system can operate
indefinitely without an LN2 refill.

The LN2 level monitor calculates the level of liquid nitrogen in the dewar,
giving you ample opportunity to schedule maintenance.

1.2. UPS INTEROPERABILITY

The MÖBIUS is designed to run on ac mains power. However, during a power
failure it acts as a conventional dewar and can keep a detector cold for
200 hours or more, depending on the level of LN2 in the dewar. When power is restored, the unit’s cryocooler restarts
and it resumes recycling nitrogen gas boil-off as before.

The unit can be connected to an uninterruptable power supply (UPS) to sustain operation during short-duration power

failures. Fully cooled, it draws about 150 watts of power from a UPS without a “smart” capability. Alternatively, the

Figure 1.

ORTEC ® MÖBIUS™ Recycler HPGe Detector Cooling System 805709F / 1115

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PROPERTY OF AMETEK, INC. – ORTEC®

MÖBIUS can run off of a “smart” UPS with a dry contact relay interface, such as the APC SMT750 UPS equipped with
their optional AP9613 dry contact management card. In this configuration, if power fails the UPS signals the MÖBIUS to
enter its power-saving mode to conserve UPS battery life. The cryocooler turns off, reducing power consumption to less
than 10 watts, while the remote status display continues to provide all status readouts including the liquid nitrogen level
in the dewar.

1.3. SPECIFICATIONS

1.3.1. Performance

● Refill Period After the detector is cool and the LN2 is topped off, the MÖBIUS system can run for 2 years or

longer without filling. This is based on the sealing technology and assumes system operation in uninterrupted,
steady-state conditions.

● Maintenance Wash or replace inlet air filter every 3 months (replacements available from ORTEC). No other

maintenance is required.

● Remote Status Display Readout unit with hardwired umbilical cord can be remotely mounted to improve

visibility when the detector is placed in a lead shield. The display registers the liquid nitrogen level in the dewar,
power level being supplied to the cooler, pressure level within dewar and general status of the system.

● Internal Controller Control electronics, power supply, and cooler electrically isolated from the dewar and

protected from LN2 spillage.

● LN2 Level Sensing Capacitance level sensor provides continuous measurement of the LN2 level from 0 - 100%

full.

● Use with UPS The MÖBIUS has a small onboard computer that can receive an input, via the rear-panel I/O

connector, in the event of power loss. The input causes the system to enter power saving mode and turn off
the cryocooler. With the cryocooler turned off, the onboard computer can be powered by a small UPS.

● LN2 Loss Rate Approximately 2 - 3 L/day with non-PopTop cryostats when cooler is off (same as for

conventional dewar); loss rate will vary depending on ambient conditions and detector size. With PopTop
cryostat typical consumption can be as high as 4L/day when cooler is off.

● Spectroscopic Performance
➢ For new ORTEC detectors purchased with the MÖBIUS: at energies above 15 keV we certify no

degradation of the detector resolution warranted on the detector data sheet, and below 15 keV, less than
10% of the warranted resolution.

➢ For existing ORTEC detectors in dipstick cryostats, where the MÖBIUS replaces an existing dewar or X-

Cooler®, resolution degradation is based on the existing detector performance. It is expected that the
detector will have similar performance compared to using a standard LN2 dewar. Some degradation may
occur depending on the detector's age and configuration. Note: Detector in a PopTop cryostat requires a

1.50 inch in diameter dipstick when converting from X-Cooler® to MÖBIUS.

➢ MÖBIUS can be used with existing non-ORTEC detectors in dipstick cryostats having 1.25 or 1.50 inch

diameter. It is expected that the detector will have similar performance compared to using a standard
LN2 dewar. Some degradation may occur depending on the detector's age and configuration.

1.3.2. Mechanical

● Dewar Capacity 28 L, excluding detector dipstick volume.

● Cooler AMETEK SUNPOWER with passive vibration dampening.