GSI - BEA Wiki

The N-DCCT is a DC beam current transformer, based on GMR magnetic sensor technology. It is designated to measure the high intensity beam currents circulating in the FAIR synchrotron SIS100. R&D were enforced by a collaboration with the University of Kassel/Dept. for Electrical Engineering/Measurement Instrumentation Group (recently concluded).

Important conditions and parameters:

• max. circulating current: ~ 2 A
• peak bunch current: ~ 150 A
• bunch revolution frequency: 1.1 - 2.7 MHz
• min. bunch width: ~ 25 ns FWHM
• aimed system bandwidth: ~ 10 MHz
• aimed resolution: ≤ 1 mA rms@full BW

Motivation: The well-known “magnetic-modulator” or “flux gate” principle up to now used in the designs of DCCTs shows disturbed performance at highest beam currents, due to interactions between signal and modulation frquencies, electronic slew rate limitations, common-mode EMI, etc.

During R&D on the GMR sensors, utilizing a magneto-optic sensor principle as well as a GMI oscillator for DCCTs also were investigated.

**The new project was started for the upcoming FAIR Synchrotron SIS100. A collaboration with the University of Kassel/Dept. Electrical Engineering has enforced research, development and construction of the N-DCCT for the SIS100.

Publications highlighting the N-DCCT: papers