Adapting a displex closed‐cycle helium refrigerator for ultrahigh vacuum operation

1980 ◽  
Vol 51 (12) ◽  
pp. 1730-1731 ◽  
Author(s):  
G. L. Fowler ◽  
J. A. Panitz
Keyword(s):  
Ultrahigh Vacuum ◽  
Closed Cycle ◽  
Helium Refrigerator

Use of a Closed Cycle Helium Refrigerator for Mössbauer Studies

1968 ◽  
Vol 39 (7) ◽  
pp. 995-997 ◽  
Author(s):  
J. W. Wiggins ◽  
J. R. Oleson ◽  
Y. K. Lee ◽  
J. C. Walker
Keyword(s):  
Closed Cycle ◽  
Mössbauer Studies ◽  
Helium Refrigerator

Measurement of the cooling capacity of an RMC‐Cryosystems Model LTS 4.5‐025 closed‐cycle helium refrigerator

1991 ◽  
Vol 62 (5) ◽  
pp. 1309-1310 ◽  
Author(s):  
R. L. de Zafra ◽  
W. H. Mallison ◽  
L. K. Emmons ◽  
D. Koller
Keyword(s):  
Cooling Capacity ◽  
Closed Cycle ◽  
Helium Refrigerator

scholarly journals Reducing the background of ultra-low-temperature X-ray diffraction data through new methods and advanced materials

2019 ◽  
Vol 52 (2) ◽  
pp. 445-450 ◽  
Author(s):  
Charles James McMonagle ◽  
Michael Richard Probert
Keyword(s):  
Diffraction Data ◽  
Advanced Materials ◽  
Average Intensity ◽  
Closed Cycle ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Methods ◽  
Fold Reduction ◽  
Scattering Contribution ◽  
Helium Refrigerator

New methods and advanced materials that significantly reduce the background when collecting single-crystal X-ray diffraction data at ultra-low temperatures using a closed-cycle helium refrigerator are presented here. These include a magnetically controlled internal beamstop and a separate internal collimator that together completely remove the scattering contribution to the background from the beryllium vacuum chamber. Additionally, a new radiation shield made from flexible graphite significantly reduces the background and maintains excellent thermal properties. In combination these improvements have led to a sixfold reduction in the average intensity and a 15-fold reduction in peak intensity of the background observed for diffraction experiments conducted with a closed-cycle helium refrigerator. Moreover, access to ultra-low base temperatures, 2.05 K, has been maintained. The design and implementation of these methods are discussed along with a case study of vitamin C to demonstrate the effectiveness of the improvements.

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