NCNR Sample Environment Projects

Yegor Vekhov
Weekly meetings with NCNR team (SE, RFO, ROE, OFPM, AMD, Safety, etc.) (Fall 2019 – Present)

Bi-weekly meetings with the Contractor on system design, etc. (Fall 2020 – Present)

Contractor’s quality control paperwork review

System commissioning – December 2022

Helium Recovery System - is a system to collect, store, purify, liquify and re-use 

Helium gas boil-off from wet cryostats / magnets, Helium pumps and transport Dewars
End-User Station (EUS) - 29 pcs and Helium Monitor Station (HMS) - 8 pcs

 Working with the Contractor on EUS and HMS conceptual designs –

finished in April 2021

 Designing and ordering interfaces between SE equipment (cryostats, He 

dewars, pumps) and EUS (about $50k+ sub-project)

 Testing EUS and HMS prototypes: design changes suggested
 SANS ILL #1 Cryostat got a leak to the vac jacket. Repair - In progress

 ICE Dil Fridge insert lost 20% of the 3He-4He mesh (incident). The mesh has been recovered. Tested. - Completed

 Hazard Review for low temperature inserts - In progress

• ICE Dil Fridge

• Oxford Dil Fridge

• 3He Insert • Big Blue

Safety
 3He MACS ILL cryostat #14: needle valve refurbishment has been ordered, 

installed, tested – Completed

 Upgrade of two ILL cryostats to three heat exchangers: more cooling power, 

faster prep and sample change times - In progress

 Damaged 70mm sample stick has been sent for repair – In progress

 New 100mm carbon fiber sample stick for MACS ILL is ordered (expected 

soon) - In progress
 Collecting the requirements from NCNR scientists

 Market research

 Talking to other neutron facilities 

 Talking to manufacturers and engineering companies

 Preparing procurement paperwork

 Submission to AMD: June 2021

 Award: September 2021

 Expected delivery: Spring 2023 (supply chain issues) 

The rotation system consist of 

• Computer controlled rotation stage to be mounted on top flange of the 100mm ILL cryostat

• Rotatable sample stick to be inserted in 100mm sample well

• Interface mounting flange adapter between rotation stage and cryostat flange

• Interface mounting flange adapter between rotation stage and rotatable sample stick

• Controller, cables, software
 Binary Gas Analyzer 

Fully integrated into dil fridge gas handling system, this 

diagnostic and troubleshooting tool allows in situ 3He4He mixture analysis.

Late 2021: Installed, tested

August 2022: First time been used to replenish the lost 

3He-4He mesh. 
 New sample holder for SANS dil fridge experiments

Collaboration with Jonathan Gaudet • Design

• Material: Al, Cu

• Thermal conductivity test • Neutron background test

First test results: • Aluminum sample holder was able to cool down to 90mK!

Next to test: • Check Cu sample holder coldest temperature

• Neutron background of both holders
 The System automatically adjusts cooling power of wet cryostats and 

magnets by closing/opening of the Needle Valve

 This adjustment works automatically based on the desired Helium 

pumping pressure. This pressure, in turn, is automatically calculated 

based on the temperature range the cryostat is at and based on the 

direction of the temperature change

 The System can be operated both manually and automatically

 The System consists of:

 standard commercial items: a step motor and its controller, 

pressure gauge, cables

 in-house designed items: Aluminum motor holder, enclosure for the 

controller and interfaces, LabView based software

 The System will be used for: ILL Orange cryostats (14 pcs), 3He insert for 

7T, SANS 9T, 10T, and 15T magnets as well as future SE systems

 The System saves labor, liquid Helium and beam time

Designed by NCNR Sample Environment group based on the ORNL original design Thanks to Alan Ye for software support
• Made in 2018

• New requirements: Needs to be liftable

Put on hold due to lack of engineering support
Solenoid cryo valve

Cryogen level controller 

Next steps: • Instrument scientists to test the system and return 

the feedback

• For BT7 and MACS: discuss system setup challenges

• Order parts for several LN2 transfer sets (FY 2023) and 

get system ready during 2023 shutdown LHe automatic transfer system –> Sergiy’s talk 
• New sample holders

• New low temperature capabilities

• New automation ideas
• ILL cryostats: maintenance, improvements, procurements 

• ICE dil fridge improvements: in situ 3He-4He mixture measurement system in 

operation

• New LN2 auto transfer system

In progress:

• Helium Recovery System

• Custom Rotation System for 100mm ILL cryostat

• Needle Valve Automatic Control for ILL cryostats (first prototype is completed)

• New Cylon 3T magnet liftable cart 

• New sample holder for SANS dil fridge experiments

• Upgrade of two ILL cryostats

• New 100mm carbon fiber sample stick for MACS ILL

• New LHe auto transfer system – Sergiy’s talk