This work presents the performance of a Sumitomo RDE-418D4 cold head up to 77 K at various frequencies and thermal loads on both stages, performed sequentially using two Sumitomo water-cooled helium compressors. The first is the F-50SH compressor with an adjustable cold head frequency, and the second is the E-77AH compressor with variable cold head as well as compressor frequencies. The cold head has been tested at 40 Hz, 50 Hz, 60 Hz, and 70 Hz and the compressor at 50 Hz and 60 Hz. A parametric study of the power dissipated on the first and second stages is conducted and the combination that yields the best performance will be presented.
These tests are being conducted as part of the qualification of the cooling system for the Caramel* cryostat project, which will be used for the mechanical characterization of materials.
 
Acknowledgement: This work is supported by the Agence Nationale de la Recherche (ANR) through the Programme d’Investissements d’Avenir under Grant No. PACIFICS ANR-21-ESRE-0049. The authors also thank Sumitomo for permitting to publish this data.
*Caramel : Cryostat for Adjustable tempeRAture MEchanicaL test.

Keywords
Cryocooler|Tests|Performances studies