Thermometers

This page is a reproduction of the content found at https://www.triumf.info/wiki/bnmr/index.php/BNMR_Thermometers and https://www.triumf.info/wiki/bnmr/index.php/BNQR_Thermometers. Though this is mainly to test the formatting of the markdown-to-html conversion, I have made minor changes throughout the text to improve readability.

Table of contents

1. β-NMR
2. β-NQR
   1. Connections
   2. Historical Notes
   3. Former Configuration

β-NMR

The β-NMR spectrometer uses an Oxford UHV cold finger cryostat.

There are two calibrated GaAlAs diode thermometers. Both are mounted to the outside of the Cu can near the sample holder socket. The LakeShore temperature controller must be set to use the correct calibration curves for these diodes and the inputs must be set to diode sensor type type GaAlAs.

Connections are made via two UHV feedthroughs. These are labelled with sensor serial numbers.

• GaAlAs serial number 10540 on channel A.
• GaAlAs serial number 10175 on channel B.

β-NQR

The low field β-NQR spectrometer uses a Cryo-Industries UHV cold finger cryostat cooled by the continuous flow of liquid helium.

There are two calibrated GaAlAs diode thermometers. Both are now mounted on the side of the Al ring with the tapered socket which holds the sample ladder. The LakeShore 331 temperature controller must be set to use the correct calibration curves for these diodes and the inputs must be set to diode sensor type type GaAlAs.

Connections

There is one 10-pin UHV feed-through on a 1.33 in mini-conflat flange. This is used to connect the LakeShore 331 controller to the two calibrated GaAlAs diodes. There is another feed-through labelled “HS Pt” for the Heat Shield platinum resistive thermometer type Pt-100, which is connected to the LakeShore 218 T-monitor.

• GaAlAs serial number 11856 on channel B (formerly GaAlAs diode serial number 11128).
• GaAlAs serial number 11134 on channel A.

Historical Notes

See:

• β-NQR Logbook 8b, pp. 70-73
• β-NQR Logbook 10, p. 165

Former Configuration

Configuration prior to around February 2010 (now obsolete).

Details regarding thermometer connections are in bNQR log book 8b, pages 70-72.

There are two Si diode thermometers. #1 is mounted on the Al block near the sample holder socket. #2 is on top of the coldfinger block (where He is vapourized.) #2 responds faster and gets slightly colder base T, but #1 is closer to the actual sample temperature. The LakeShore 331 temperature controller must be set to use the standard DT-470 calibration curve for both diodes, and the inputs set to diode type.

Connections: There is one 10-pin UHV feedthrough on a 1.33inch miniconflat flange. This is used to connect the LakeShore 331 controller to the two Si diodes. There is another feedthrough labelled HS Pt for the Heat Shield platinum resistive thermometer.

Each Si diode is connected via four-conductor (LakeShore polyimide Quad-lead). There are nonmagnetic gold-plated pin-and-socket connectors mounted in teflon blocks at the heat shield mounting ring. (See photos) 10-pin connector:

Some photographs (of the previous configuration taken in April 2007): Old Si diodes: http://trshare.triumf.ca/~gmorris/bNQR/equipment/cryostat/thermometry/photos/Si-diodes/

Former installation of one GaAlAs diode on the Al ring. http://trshare.triumf.ca/~gmorris/bNQR/equipment/cryostat/thermometry/photos/GaAlAs-diodes/