Design and performance of an HTS current comparator for charged-particle-beam measurements

Author

Hao, L. ; Macfarlane, J.C. ; Peden, D.A. ; Lee, R.A.M. ; Gallop, J.C. ; Carr, C.

Author_Institution

Nat. Phys. Lab., Teddington, UK

Volume

11

Issue

1

fYear

2001

fDate

3/1/2001 12:00:00 AM

Firstpage

635

Lastpage

638

Abstract

Superconducting direct current comparators are well established for operation at liquid helium temperatures. We have begun investigations into HTS Cryogenic Current Comparator designs, which incorporate a flux concentrator and readout SQUID also made from HTS. This work aims to produce a system capable of high accuracy, non-invasive, measurements of an ion or electron beam current in the range ~10 nA to 1 mA. We outline a proposal for a precise determination of the faraday fundamental constant, using purely physical systems, and employing an HTS CCC for charged particle beam current measurement. In addition estimates of the potential current sensitivity are reported, based on measurement results of a prototype system, and proof-of-principle measurements of ion beam currents are described. The design and construction of a robust, compact cryogenic unit suitable for further, more realistic, field trials are discussed

Keywords

SQUIDs; constants; current comparators; electric current measurement; high-temperature superconductors; particle beam diagnostics; 10 nA to 1 mA; Faraday fundamental constant; charged particle beam measurement; cryogenic current comparator; electron beam; flux concentrator; high temperature superconductor; ion beam; readout SQUID; Cryogenics; Current measurement; Electron beams; Helium; High temperature superconductors; Particle beam measurements; Particle beams; Proposals; Prototypes; SQUIDs;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.919424

Filename

919424