Beam current sensor

Patent · 01 January 1987

OSTI ID:866344

Kuchnir, Moyses ^[1]; Mills, Frederick E ^[2]

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1. Elmhurst, IL
2. Elburn, IL

A current sensor for measuring the DC component of a beam of charged particles employs a superconducting pick-up loop probe, with twisted superconducting leads in combination with a Superconducting Quantum Interference Device (SQUID) detector. The pick-up probe is in the form of a single-turn loop, or a cylindrical toroid, through which the beam is directed and within which a first magnetic flux is excluded by the Meisner effect. The SQUID detector acts as a flux-to-voltage converter in providing a current to the pick-up loop so as to establish a second magnetic flux within the electrode which nulls out the first magnetic flux. A feedback voltage within the SQUID detector represents the beam current of the particles which transit the pick-up loop. Meisner effect currents prevent changes in the magnetic field within the toroidal pick-up loop and produce a current signal independent of the beam's cross-section and its position within the toroid, while the combination of superconducting elements provides current measurement sensitivites in the nano-ampere range.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• DOE Contract Number: AC02-76CH03000
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 4687987
• OSTI ID: 866344
• Country of Publication: United States
• Language: English

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