"Wet" System - Standard Sample Loading - Sample in exchange gas
The model HE-3-SSXGAS insert is designed for standard sample loading with sample in exchange gas, and this model of He-3 insert is developed for experiments with special samples that cannot be bolted tightly to the sample holder, such as powder, liquid, and very fragile samples; or for samples with very poor thermal conductivities.
The sample chamber is located at the bottom of the He-3 pot and exchange gas is introduced into the sample chamber to aid in cooling down the sample.
A model HE-3-XGHS mini-exchange gas handling system (see HE-3-XGHS tab) is usually included at the top of the insert and it provides the He-3 exchange gas required for the sample cooling. The design minimizes the cost of the expendable exchange gas for each run to approximately US$2.00 (depending on the geographic location).
This He-3 insert includes the following components:
- Charcoal sorption pump with heater and thermometer
- 1 K pot with thermometer
- He-3 pot with heater and thermometer
- Permanently stored He-3 gas
- IVC can
- Sample chamber
- Mini-exchange gas handling system
- Operation test
- Resistive and/or superconducting wires
- Coaxial cables
- Clear shots to IVC
- Computer controller motorized 1 K pot cryogenic needle valve
- 1 K cold plate
- High efficiency helium dewar
- Sliding seal
- Automatic temperature controller
- Superconducting magnet
- Magnet support with high current leads
- Magnet power supply
- IVC tail for superconducting magnet
- "10 K" radiation shield for operating temperature up to 300 K in full magnetic fields
- Liquid helium level probe
- Digital cryogen monitor
- Liquid helium transfer line
- 1 K pot pumping station
- Turbo pumping station
Base temperature: 300 mK
Holding time at base temperature: 24 hours (typical)
Operation temperature range: 0.3 K - 80 K (300 K optional)
Sample space: As required
The model HE-3-XGHS mini-exchange-gas handling system is designed to introduce He-3 exchange gas into the IVC can or the sample chamber of the main He-3 cryostat. It is typically supplied for use with the model HE-3-SSXGAS He-3 insert.
This compact mini-gas handling system allows complete control of the amount of He-3 exchange gas used in a very cost effective manner, with the typical cost of He-3 exchange gas for each run amounting to approximately $2.00 (depending on the geographic location and current cost of 3He gas).
The total amount of He-3 exchange gas included in this mini-exchange gas handling system is typically 1 to 3 STP liters; the gas is located in a safe re-usable high pressure gas chamber located on top of the cryostat.
"Dry" System, Sample in Vacuum or Exchange Gas
Was designed for a neutron scattering application, but could easily be adapted for other applications requiring samples cooled in exchange gas in a cryogen-free system.