Title :
Towards a sub-femto ampere current amplifier based on a cryogenic current comparator
Author :
Rengnez, F. ; Séron, O. ; Devoille, L. ; Piquemal, F.
Author_Institution :
LNE, Trappes, France
Abstract :
A Cryogenic Current Comparator (CCC) used as a SET current amplifier with a maximum gain of 30 000 has been developed at LNE. The equivalent input current noise was found very close to 1 fA/Hz1/2 in the white noise regime. Thanks to the axial superposition of windings, the smallest value of self-resonance frequency was measured at 3 kHz, thus pushed well beyond the SQUID bandwidth. CCC errors were investigated, based on 1:1 ratio measurements carried out both on windings of small and large number of turns.
Keywords :
SQUIDs; cryogenic electronics; current comparators; radiofrequency amplifiers; white noise; windings; CCC; LNE; SET current amplifier; SQUID bandwidth; axial winding superposition; cryogenic current comparator; equivalent input current noise; frequency 3 kHz; gain 30000 dB; self-resonance frequency measurement; subfemto ampere current amplifier; white noise regime; Cryogenics; Current measurement; Measurement uncertainty; Noise; Resonant frequency; SQUIDs; Windings; Cryogenic Current Comparator (CCC); single electron tunneling; small-current measurement;
Conference_Titel :
Precision Electromagnetic Measurements (CPEM), 2012 Conference on
Conference_Location :
Washington, DC
Print_ISBN :
978-1-4673-0439-9
DOI :
10.1109/CPEM.2012.6250705
