1. Manuals
  2. Brands
  3. TRISTAN TECHNOLOGIES Manuals
  4. Microscope
  5. SMM-770
  6. Operating manual

TRISTAN TECHNOLOGIES SMM-770 Operating Manual

Scanning magnetic microscope
Hide thumbs
Table of Contents

Advertisement

Quick Links

Download this manual
Scanning Magnetic
Microscope
Model SMM-770
Operating Guide
TRISTAN TECHNOLOGIES, Inc
San Diego, California
USA
www.tristantech.com

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the SMM-770 and is the answer not in the manual?

Questions and answers

Summary of Contents for TRISTAN TECHNOLOGIES SMM-770

  • Page 1 Scanning Magnetic Microscope Model SMM-770 Operating Guide TRISTAN TECHNOLOGIES, Inc San Diego, California www.tristantech.com...
  • Page 2 Model SMM 770 Scanning Magnetic Microscope System Operating Guide Single channel HTS SQUID microscope Model SMM-770 Option 77P, 77V, 77T, 77B, 77HR, MS-770 TRISTAN TECHNOLOGIES, Inc San Diego, California © Copyright 2005 www.tristantech.com TRISTAN TECHNOLOGIES --Page 2...
  • Page 3 TRISTAN TECHNOLOGIES Inc. TRISTAN TECHNOLOGIES Inc. reserves the right to change the functions, features, or specifications of its products at any time, without notice. Any questions or comments in regard to this product and other products from Tristan Technologies, please contact or see http://www.tristantech.com...
  • Page 4 TRISTAN TECHNOLOGIES service agent. All repairs will be warranted for only the unexpired portion of the original warranty, plus the time between receipt of the instrument at TRISTAN TECHNOLOGIES and its return to the owner. This warranty is limited to TRISTAN TECHNOLOGIES’ products that are purchased directly from TRISTAN TECHNOLOGIES, its OEM suppliers, or its authorized sales representatives.

  • Page 5: Table Of Contents

    SENSORS AND CONTROL ELECTRONICS WIRING DIAGRAM SENSOR INITIAL PERFORMANCE TEST MEASURED PARAMETERS AND FACTORY TEST DATA SENSOR CALIBRATION SYSTEM SOFTWARE START EXCITATION TRACK CONSTRUCTION MOVE MANUALLY SQUID PARAMETERS ACQUISITION PARAMETERS FILTER PARAMETERS SCAN CONTROLS OUTPUT FILE 4.10 VIDEO CAMERA TRISTAN TECHNOLOGIES --Page 5...
  • Page 6 Figure 3-2 SMM770 detailed wiring diagram ..............21 Figure 3-3: Manufacturer-supplied noise spectrum and tune specs........22 Figure 3-4 SQUID noise spectrum at (0-200Hz), 81.8 Kelvin, gain=x100......24 Figure 3-5 SQUID noise spectrum at (0-3.2 kHz), 81.8 Kelvin, gain=x100....... 24 TRISTAN TECHNOLOGIES --Page 6...
  • Page 7 Figure 4-20 Gap between the windown and sample as seen by the video camera ....50 Figure 5-1 Measured boil off rate ..................52 Figure 6-1 Passive Newport table vs. Newport table with the Activator installed in a horizontal configuration....................54 TRISTAN TECHNOLOGIES --Page 7...
  • Page 8 Figure 6-4 Field profile along Z axis of magnetic ring............56 Figure 6-5 Field profile along y and x axis of magnetic ring ..........57 Figure 6-6: Noise spectra of SMM-770 system with 5.5 Gauss external applied field, Gain x100 Figure 6-7: Noise spectra of SMM-770 system with 5.5 Gauss external applied field, Gain...
  • Page 9 Community; whereas this Directive applies to equipment subject to a maximum allowable pressure exceeding 0,5 bar”. Since the maximum allowable design pressure is less than 0.5 bar, Tristan’s model SM770 is in conformity with DIRECTIVE 97/23/EC. TRISTAN TECHNOLOGIES --Page 9...

  • Page 10: System Overview

    Model SMM 770 Scanning Magnetic Microscope System 1. SYSTEM OVERVIEW The Model SMM-770 Scanning Magnetic Microscope System is a close spaced HTS SQUID magnetometer system (Figure 1-1) that has been designed and built by Tristan to detect B magnetic field. The main system consists of:...

  • Page 11: Figure 1-2: Microscope Setup

    FIBER OPTIC LIGHT VIDEO MICROSCOPE SQUID WINDOW SPACER PLATE (OPTIONAL) X-Y MICRO TILT STAGE Z-AXIS, MANUAL Z-AXIS DIGITAL READOUT X-Y AXIS, MOTORIZED VIBRATION TABLE TOP ACTIVE DAMPING (3 UNITS) VIBRATION ISOLATION AIR TABLE Figure 1-2: Microscope Setup TRISTAN TECHNOLOGIES --Page 11...

  • Page 12: Initial Inspection

    Please be prepared to discuss all surrounding circumstances, including installation and connection details. After obtaining authorization from the Tristan Technologies representative, return the unit for repair along with a tag on it identifying yourself as the owner. Please enclose a letter describing the problem in as much detail as possible.
  • Page 13 Motion Control card, National Instruments, model PCI-7342, s/n DF5E03 Video card, National Instruments, model PCI-1405, s/n 111FD9C LabView custom software ,MagScan version 3.0 • Video monitors, 19”: Dell, model DP/N-0G6566, s/n CN-0G6566-47804-51U-U3V2 s/n CN-0G6566-47804-51U-U3MU • Compressor: Jun-Air, model 3-04, s/n 582261 TRISTAN TECHNOLOGIES --Page 13...
  • Page 14 • Active Damping System: Newport Optics Activator AD500, model NVX-1206-1, s/n 4076-0059 s/n 4076-0072 s/n 4076-0076 • Oriel micrometer 1400 • Battery for oriel micrometer, SR44, 1.5V, No 938882 • MuMetal Shield 2104-S100-4 • Accessory pack Dewar o-ring 166, Qty. 2 TRISTAN TECHNOLOGIES --Page 14...
  • Page 15 Nose piece screws 4-40-1/4” SHCS, Brass Spacer plate Screws ¼”-20 SHCS • System Manuals SMM-770 system manual Dell Precision workstation 370 Quick Reference Guide Dell Desktop Computers Product Information Guide Dell Drivers and User Documentation E193FP LCD Monitor CD (2)

  • Page 16: Cryogenic System

    Model SMM 770 Scanning Magnetic Microscope System 2. CRYOGENIC SYSTEM The cryogenic system includes a fiberglass liquid nitrogen dewar (Figure 2-1). The sensor- window gap is pre-set at the factory and does not need adjustment. Figure 2-1: Cryogenic Dewar TRISTAN TECHNOLOGIES --Page 16...

  • Page 17: Liquid Nitrogen Maintenance

    Plugged passages are hazardous because of the continual need to vent the nitrogen gas that evolves as the liquid continuously evaporates. Therefore, always store and handle liquid nitrogen under positive TRISTAN TECHNOLOGIES --Page 17...
  • Page 18 If a person becomes groggy or loses consciousness when working around nitrogen, get them to a well-ventilated area immediately. If breathing has stopped, apply artificial respiration. If a person loses consciousness, summon a physician immediately. TRISTAN TECHNOLOGIES --Page 18...

  • Page 19: General Information

    • Do not fill with liquid nitrogen unless dewar vacuum is < 50 microns. • Transfer nitrogen with fill tube inserted to the dewar bottom. • Do not touch sapphire window at any time ever! TRISTAN TECHNOLOGIES --Page 19...

  • Page 20: Sensors And Control Electronics

    2 Pt Thermo and 1 heater Shield DC Magnet SQUID CCD Camera Stratford LCD X, Y stage motion Micrometer and Z manual Anti Vibration Table Active Vibration Control Compressor SMM-770 Naples Figure 3-1 Overview of SMM770 wiring diagram TRISTAN TECHNOLOGIES --Page 20...

  • Page 21: Figure 3-2 Smm770 Detailed Wiring Diagram

    Model SMM 770 Scanning Magnetic Microscope System Figure 3-2 SMM770 detailed wiring diagram TRISTAN TECHNOLOGIES --Page 21...

  • Page 22: Sensor Initial Performance Test

    These tests determine the bandwidth and voltage transfer function for the device. Operation at various gains and ranges are verified using the customer’s electronics. Testing is done using Hewlett-Packard (34401 A DMM, 35665A dynamic signal analyzer) and other appropriate test equipment. TRISTAN TECHNOLOGIES --Page 22...
  • Page 23 HTS SQUID sensors typically show a 10 - 30% variation from device to device. Table 3-2 and summarize the main system’s parameters and SQUID performance Table 3-2 using a Tristan Technologies, Inc. iMC-303 iMAG SQUID Controller. ® Table 1 System Parameters...

  • Page 24: Figure 3-4 Squid Noise Spectrum At (0-200Hz), 81.8 Kelvin, Gain=X100

    Model SMM 770 Scanning Magnetic Microscope System Figure 3-4 SQUID noise spectrum at (0-200Hz), 81.8 Kelvin, gain=x100 Figure 3-5 SQUID noise spectrum at (0-3.2 kHz), 81.8 Kelvin, gain=x100 TRISTAN TECHNOLOGIES --Page 24...

  • Page 25: Sensor Calibration

    The SQUID sensitivity is determined and the system resolution is calculated. The following charts and graphs show the data for this unit. The system calibration for a typical SQUID is calibrated as follows: Table 3-3: Calibration Parameters for SMM-770 Close Wire Spacing Wide Wire Spacing SQUID to Wire Lift-off 0.003”...
  • Page 26 0.00E+00 T -1.00E-06 T -2.00E-06 T -2 mm -1.5 mm -1 mm -0.5 mm 0 mm 0.5 mm 1 mm 1.5 mm 2 mm Figure 3-8: Horizontal scans at increasing liftoffs to parallel wires 0.009” apart. TRISTAN TECHNOLOGIES --Page 26...
  • Page 27 However, this is more easily understood visually by illustrating the accuracy at which the center of a single magnetic source can be located. Figure 3-11 shows the peak region of a horizontal scan across parallel wires spaced 76 microns apart. Each data point is spaced 50 TRISTAN TECHNOLOGIES --Page 27...
  • Page 28 6.60E-06 T 6.40E-06 T 6.20E-06 T 6.00E-06 T -0.3 mm -0.2 mm -0.1 mm 0 mm 0.1 mm 0.2 mm 0.3 mm Figure 3-11: Central peak of a horizontal scan across 76 micron separation meander coil TRISTAN TECHNOLOGIES --Page 28...
  • Page 29 “STATES” on the front above the bust of Washington. Figure 3-12: US Dollar bill Figure 3-13: Image showing what a small amount of processing can accomplish TRISTAN TECHNOLOGIES --Page 29...
  • Page 30 Model SMM 770 Scanning Magnetic Microscope System Figure 3-14:: The following output of data is a 3D post processing of the image shown in Figure 3-13. TRISTAN TECHNOLOGIES --Page 30...

  • Page 31: System Software

    Note that the iMAG unit must have its GPIB address = 15, which can be set from the front panel. After the iMAG unit is configured, the user will then see a progress bar indicating configuration and homing of the sample stage. TRISTAN TECHNOLOGIES --Page 31...
  • Page 32 Pressing <control>-H will pop-up a help window for any item that the mouse cursor is over. This help window provides a description of what each control and indicator does. TRISTAN TECHNOLOGIES --Page 32...

  • Page 33: Excitation

    The Excitation tab controls the application of a signal to an excitation coil or sample. This option is disabled for this SMM-770 delivery. Assorted controls related to excitation, such as phase shift and its real and imaginary components, are disabled throughout the user interface.
  • Page 34 If the QuikScan parameters are improperly set, an error message will be clearly displayed and the graph grayed out. The user will be offered suggestions as to how to change the parameters to create a valid QuikScan track. TRISTAN TECHNOLOGIES --Page 34...

  • Page 35: Move Manually

    Model SMM 770 Scanning Magnetic Microscope System Figure 4-5: Preview of QuikScan (continuous) track 4.4 MOVE MANUALLY The Move tab manually controls the stage. This is useful for moving the stage to a position where it is easier to change samples. TRISTAN TECHNOLOGIES --Page 35...

  • Page 36: Squid Parameters

    This is of special concern with the gain setting. The data output of the iMAG can be viewed in the Raw Data tab. This is especially useful during a manual tune of the iMAG. TRISTAN TECHNOLOGIES --Page 36...

  • Page 37: Acquisition Parameters

    The resulting block of data is processed to calculate DC and AC components that provide a measure of the magnetic field strength at the particular sample location. TRISTAN TECHNOLOGIES --Page 37...

  • Page 38: Filter Parameters

    The Filter tab controls the software filtering of raw SQUID data. This is not to be confused with the hardware filtering of raw SQUID data that can be selected using the the iMAG HiPass and LoPass filters. TRISTAN TECHNOLOGIES --Page 38...

  • Page 39: Scan Controls

    In general, these filter settings are only useful for minimizing the Mains noise seen under the Raw Data tab. They will not have much affect on the calculation of DC and AC components. 4.8 SCAN CONTROLS The Scan tab controls collection of magnetic field data from a sample. TRISTAN TECHNOLOGIES --Page 39...
  • Page 40 The Start Scan button will initiate discrete scanning using the track defined under the Track tab. This scanning can be stopped by pressing the button again. The progress of the scanning can be viewed by using the Map button. This button shows the progress of the scanning. TRISTAN TECHNOLOGIES --Page 40...
  • Page 41 This will be performed only once. As scanning proceeds, the data will be plotted as a stripchart under the Mag & Phase tab, and plotted in the 3D graph on the right, as shown below: TRISTAN TECHNOLOGIES --Page 41...
  • Page 42 <shift>-rightclick, and zoomed by <alt>-rightclick. The current location of the scan stage is indicated by a red dot. Settings under the Surface tab allow the user to add various features such as contour lines, a cursor, or illumination control, as shown in the figures below: TRISTAN TECHNOLOGIES --Page 42...
  • Page 43 Model SMM 770 Scanning Magnetic Microscope System Figure 4-13: Contour lines in the 3D plot TRISTAN TECHNOLOGIES --Page 43...
  • Page 44 Model SMM 770 Scanning Magnetic Microscope System Figure 4-14: Cursor usage in the 3D plot TRISTAN TECHNOLOGIES --Page 44...
  • Page 45 This is useful for selecting a smaller scan region for more detailed study. The Z-axis tab controls scaling and trimming of the Z-axis. TRISTAN TECHNOLOGIES --Page 45...

  • Page 46: Output File

    Pressing the camera button will capture an image and save it with an automatically- generated name, consisting of the date and time. It will be stored under c:\MagScan\Experiment_Data\<YYYYMMM>\<date>_<time>_3DImage.bmp. 4.9 OUTPUT FILE The File tab controls saving and loading of the scan data. TRISTAN TECHNOLOGIES --Page 46...
  • Page 47 The user description is entered here. <end description> <start miscvar> File Format Version Scan Start Time 3198091711.3 Scan Stop Time 3198093717.5 Total Scans 0.00 Total Samples 0 Total Channels 1 Minimum XYZ -50.00,-50.00,0.00 Maximum XYZ 50.00,50.00,0.00 Resolution XYZ 10.0000,10.0000,1.0000 TRISTAN TECHNOLOGIES --Page 47...
  • Page 48 Sample versus Reference, the two files must have identical tracks. Stored *.quk (continuous QuikScan data) files can not be retrieved for display. Data files can be deleted by pressing the Delete button. This will pop-up a panel for editing the data files, as shown below: TRISTAN TECHNOLOGIES --Page 48...
  • Page 49 Model SMM 770 Scanning Magnetic Microscope System Figure 4-19: Deletion of data files TRISTAN TECHNOLOGIES --Page 49...

  • Page 50: Video Camera

    Pressing the camera button will capture an image and save it with an automatically- generated name, consisting of the date and time. It will be stored along with the scan data files under c:\MagScan\Experiment_Data\<YYYYMMM>\<date>_<time>_Camera.bmp. Figure 4-20 Gap between the windown and sample as seen by the video camera TRISTAN TECHNOLOGIES --Page 50...

  • Page 51: Service And Maintenance

    Do not allow water to drip into the neck! This will quickly seal the dewar creating a serious explosion hazard. Remove blockages at once with a hot metal rod or compressed nitrogen flowing through a tube! TRISTAN TECHNOLOGIES --Page 51...
  • Page 52 Dewar is warm when the vacuum is lost, the available moisture in air is enough to ruin the SQUID within ~20 minutes. If an emergency seal and vacuum pump cannot be applied immediately, an airtight bag with desiccant packets can be used to store the TRISTAN TECHNOLOGIES --Page 52...

  • Page 53: Gantry Maintenance

    The SMM770, IsoStation Vibration Isolated Workstation air suspension table is equipped with an active damping system from Newport. The Optics Activator AD500, model NVX-1206-1, improves low frequency performance providing a 12db gain at 1Hz and 500 lb. TRISTAN TECHNOLOGIES --Page 53...

  • Page 54: Option 77T Tilt Tip Frame

    Passive Newport table vs. Newport table with activator and without activators and load of 500lbs. 6.3 Option 77T Tilt Tip Frame ¼-20 thread 3” base 15 degree plane and knob has 360 degree of marks. e.g. - one turn of knob is 17 micron at the left edge. TRISTAN TECHNOLOGIES --Page 54...

  • Page 55: Option 77B Fixed Field Capability

    A 1 deg turn of the tilt adjustment thus causes 150 mm*tan(0.1165deg/360deg) = 0.847 uM height change across the stage. 6.4 Option 77B Fixed Field Capability The system was tested with a ring of magnets attached to the bottom of the system. The ring is shown in Figure 6-3. TRISTAN TECHNOLOGIES --Page 55...
  • Page 56 The field profile for the ring for an unshielded laboratory measurement utilizing a Hall probe is shown in Figure 6-4 and Figure 6-5. Field along Z-axis -55 -45 -35 -25 -15 Distance (mm) Figure 6-4 Field profile along Z axis of magnetic ring TRISTAN TECHNOLOGIES --Page 56...
  • Page 57 Figure 6-5 Field profile along y and x axis of magnetic ring The system ran well with this field applied. There was very little change in the fft and the bandwidth remained >10Khz. See the Figures below: TRISTAN TECHNOLOGIES --Page 57...
  • Page 58 Model SMM 770 Scanning Magnetic Microscope System Figure 6-6: Noise spectra of SMM-770 system with 5.5 Gauss external applied field, Gain x100 TRISTAN TECHNOLOGIES --Page 58...

  • Page 59: Option 77Hr 12.5 Micron Step Capacity

    Model SMM 770 Scanning Magnetic Microscope System Figure 6-7: Noise spectra of SMM-770 system with 5.5 Gauss external applied field, Gain x20 6.5 Option 77HR 12.5 Micron Step Capacity The stage was supplied with a nominal step resolution of 1/2000 mm. The maximum recommended speed is 240 rpm, and manufacture’s stated repeatability is +/- 3µm.
  • Page 60 In the event miss-handling or accident causes the interior magnetic shielding is degraded, contact Tristan for instructions on degaussing the shield. Shielding Tested –May 2005 50Hz testing with APS 520A Fluxgate Magnetometer and SR770 Spectrum Analyzer. TRISTAN TECHNOLOGIES --Page 60...
  • Page 61 4. Rear port: 5" id x 6" length, center is 15" from lower edge and at "12:00 o'clock”: access for video camera and adjustments; cap with 1/2" diam cable feedthrough access (these cables could also be lead through the #3 port as well, if it is a shielding compromise. Figure 6-9 Option MS-770 two layer mu metal shield TRISTAN TECHNOLOGIES --Page 61...

  • Page 62: Appendices

    33µV 77.42 (+/- 0.01) Pt100/385 Probe Tip 95.00 SMM770 Cooldown 90.00 85.00 SQUID Tip 80.00 Cu bundle 75.00 0:00 1:12 2:24 3:36 4:48 Time (Hours) Figure 7-1 Elapsed time for SQUID tip coldwon to operating temperatures TRISTAN TECHNOLOGIES --Page 62...

  • Page 63: Calculating B-Fields

    Model SMM 770 Scanning Magnetic Microscope System 7.2 Calculating B-fields This section is for assistance in calculating various magnetic fields for different geometries. Units are cgs. 7.2.1 Dipole: TRISTAN TECHNOLOGIES --Page 63...
  • Page 64 Model SMM 770 Scanning Magnetic Microscope System 7.2.2 Field at center of loop: 7.2.3 Field above straight wire. TRISTAN TECHNOLOGIES --Page 64...
  • Page 65 ⎢ ⎥ − ⎣ ⎦ Where: Separation between wires (0.00762 cm) x horizontal distance with respect to meander center (cm) h Vertical liftoff from meander center to SQUID (cm) Current flowing the meander given in amperes TRISTAN TECHNOLOGIES --Page 65...

  • Page 66: Wiring And Hardware Configuration

    On back of BNC-2090, switch set to MIO-16 7.3.1 Ini file description [Comm] FLL_RS232_Resource=ASRL1::INSTR If RS-232 communication is used for the iMAG unit, this specifies the RS-232 port to use. The available ports are listed under NI-MAX. FLL_GPIB_Resource=15 TRISTAN TECHNOLOGIES --Page 66...
  • Page 67 Default track maximum for X, Y, and Z axes. Track_Res_(mm)=10,10,1 Default track step size for X, Y, and Z axes. Z_Active=FALSE Specifies whether there is a motor for control of the Z axis. Either "TRUE" or "FALSE". Scan_Count_(N)=10 TRISTAN TECHNOLOGIES --Page 67...
  • Page 68 Default amplitude of the excitation signal. Samples_Per_Buffer_(N)=250 Points in the excitation buffer. Cycles_Per_Buffer_(N)=5 Periodic cycles in the excitation buffer. Offset_(V)=0.00 Default amplitude of the excitation signal. Allowed values are in the range -10 to 10 V. Type=SineWave TRISTAN TECHNOLOGIES --Page 68...
  • Page 69 Calibration of the SQUID array for gains of x1 thru x500. Calibrations for differet gains are delimited by commas, and sets for each channel are delimited by semicolons. For example, a set of nine SQUIDs could have “2.45e-5, 2.45e-5, 2.45e-5, 2.45e-5, 2.45e-5, 2.45e-5, 2.45e-5, 2.45e-5, 2.45e-5; TRISTAN TECHNOLOGIES --Page 69...
  • Page 70 Active=FALSE Default enable/disable of the software filtering. Either "TRUE" or "FALSE". Topology=IIR_Butterworth Default software filter topology. Either "IIR_Butterworth", "IIR_Chebyshev", "IIR_InverseChebyshev", "IIR_Elliptic", "IIR_Bessel", or "FIR_Window". Type=Lowpass Default software filter type. Either "Lowpass", "Highpass", "Bandpass", or "Bandstop". FIR_Window=None TRISTAN TECHNOLOGIES --Page 70...
  • Page 71 Either "Linear" or "Exponential". FFT_AvgNum=10 Number of running averages for the FFT display. FFT_Window=None Either "None", "Hanning", "Hamming", "BlackmanHarris", "ExactBlackman", "Blackman", "FlatTop", "4TermBHarris", "7TermBHarris", or "LowSidelobe". Type=Sample Default 3D display type. Either "Sample", Reference", or "SampleVsReference". TRISTAN TECHNOLOGIES --Page 71...
  • Page 72 Default 3D display illumination longitude. Transparency_A=0 Default 3D display transparency for Sheet A. Transparency_B=0 Default 3D display transparency for Sheet B. Photo=BMP File format for screen captures. Either "JPG", "PNG", or "BMP". [Misc] Code=39 Reserved Language=English.txt Reserved TRISTAN TECHNOLOGIES --Page 72...

  • Page 73: Background Subtraction

    The following two figures show the capability of scan subtraction. The first Figure shows a background scan in an unshielded environment. The second Figure shows the result of subtracting two consecutive background scans. Figure 7-2 Unsubtracted background TRISTAN TECHNOLOGIES --Page 73...

  • Page 74: Stage Calibration

    Full 360 deg turn of knob, across 150 mm left +17 mil, right -5 mil, 0.1165 deg 27 May 05 Y tilt: Full 360 deg turn of knob, across 150 mm back +17 mil, front -5 mil, 0.1165 deg 27 May 05 TRISTAN TECHNOLOGIES --Page 74...

  • Page 75: Hts Squid Handling Cautions

    9. Leave SQUID cooling down after heating for about 2 min. Then run TUNE again. When turning the system off DO remove the fiber-optic power cable first from the FLL and then turn off AC power. TRISTAN TECHNOLOGIES --Page 75...
  • Page 76 Electronics or equivalent heating circuit) at when the SQUID sensor is at room temperature. • Ship the SQUID sensor with the shunting plug attached and in a closed container with desiccant inside. • NEVER allow the SQUID to sit in a sealed dewar with water condensed on the bottom. TRISTAN TECHNOLOGIES --Page 76...

Table of Contents