Low noise LTS SQUIDs for application in gravitational experiments

Author

Vodel, W. ; Koch, H. ; Nietzsche, S. ; Zameck Glyscinski, J.V. ; Dittus, H. ; Lochmann, S. ; Mehls, C.

Author_Institution

Inst. fur Festkorperphys., Friedrich-Schiller-Univ., Jena, Germany

Volume

7

Issue

2

fYear

1997

fDate

6/1/1997 12:00:00 AM

Firstpage

3343

Lastpage

3346

Abstract

The Weak Principle of Equivalence (WEP) is proved up to now with an accuracy of 1/spl times/10/sup -12/. Short range free fall experiments attained an accuracy of 5/spl times/10/sup -10/ only. Microgravity facilities such as the "Drop Tower Bremen" enables long range free fall experiments which may improve the accuracy of free fall tests to <10/sup -12/ using high performance SQUID measuring technique. In this review the application of LTS DC SQUIDs with Nb-NbO/sub x/-Pb/In/Au window-type Josephson junctions for gravitational experiments is described. Under optimal conditions a noise limited sensitivity of 1.4/spl times/10/sup -12/ m//spl radic/(Hz) for the position detector was achieved corresponding to a flux noise of the SQUID system of 2/spl times/10/sup -6/ /spl Phi//sub 0///spl radic/(Hz). The contribution gives the design of the DC SQUID position detector and summarizes recent results of its application in gravitational experiments.

Keywords

SQUIDs; gravitational experiments; superconducting device noise; zero gravity experiments; Drop Tower Bremen; LTS DC SQUID; Nb-NbO-Pb-In-Au; Nb-NbO/sub x/-Pb/In/Au window-type Josephson junction; flux noise; free fall; gravitational experiment; measurement technique; microgravity facility; position detector; sensitivity; weak principle of equivalence; Delay effects; Detectors; Displacement measurement; Gravity; Performance evaluation; Poles and towers; SQUIDs; Superconducting coils; Testing; Time measurement;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.622082

Filename

622082