Abstract
This study details the design and characterisation of a cryogenic test facility for low-noise amplifiers (LNAs) used in radio astronomy. Following a review of available cooling and vacuum pumping methods, a dedicated test system was designed and manufactured to meet specific performance requirements. Mathematical models were developed to predict the thermal and pressure behaviors within the cryostat, enabling accurate assessments of the system’s cooling efficiency. Experimental results showed that the first and second stages reached minimum temperatures of 11 K and 38 K, closely aligning with the calculated values of 13 K and 42 K, respectively. Vacuum testing across the pumping station, manifold, and cryostat produced pressure readings of 4·10-7 mbar, 1.5·10-5 mbar, and 2.5·10-5 mbar, respectively, indicating effective vacuum conditions. Analysis of pressure decay revealed that outgassing significantly contributed to the gas load, exceeding O-ring permeation, with hydrogen identified as the predominant gas because of stainless steel components. These findings underscore the importance of vacuum baking to reduce maintenance requirements. This work provides practical insights into the design and operation of cryogenic systems, promoting efficient setup and extended operational time frames, ultimately enhancing observational capability in radio astronomy applications.
Recommended Citation
MAKOMBORE, Tapuwa and BELLO-OCHENDE, Tunde
(2025)
"Thermal analysis and experimental design of a cryogenic system for low-noise amplifiers,"
Seatific Journal: Vol. 5:
Iss.
1, Article 3.
https://doi.org/10.29187/2792-0771.1035
Available at:
https://commons.yildiz.edu.tr/seatific/vol5/iss1/3
