Title :
Improved Cryogenic Current Comparator Setup With Digital Current Sources
Author :
Götz, Martin ; Drung, Dietmar ; Pesel, Eckart ; Barthelmess, Henry-Jobes ; Hinnrichs, Colmar ; Assmann, Cornelia ; Peters, Margret ; Scherer, Hansjörg ; Schumacher, Bernd ; Schurig, Thomas
Author_Institution :
Phys.-Tech. Bundesanstalt, Braunschweig
fDate :
4/1/2009 12:00:00 AM
Abstract :
We have realized an improved resistance calibration setup based on a cryogenic current comparator (CCC). The new comparator with 18 windings and a total of 4647 turns suits well for all the necessary comparisons of a 100-Omega standard resistor with the quantum Hall effect (QHE) and within the range of standard resistance values from 1 Omega to 1 MOmega. The new state-of-the-art setup is equipped with a dc superconducting quantum interference device (SQUID) and a digital double current source, allowing a reduction in the ramping time by at least one order of magnitude and significantly improving the dynamic stability of the system. The latter also benefits from the internal wideband feedback that we present in this paper.
Keywords :
SQUIDs; constant current sources; cryogenic electronics; current comparators; feedback; quantum Hall effect; stability; SQUID; cryogenic current comparator; dc superconducting quantum interference device; digital current sources; digital double current source; dynamic stability; internal wideband feedback; quantum Hall effect; ramping time reduction; resistance 1 ohm to 1 Mohm; resistance calibration setup; standard resistor; Current comparators; Superconducting Quantum Interference Device (SQUID); feedback circuits; magnetic shielding; resistance measurements;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
DOI :
10.1109/TIM.2008.2012379
