DIPAC2011 - List of Authors (Völklein, F.)

Paper

Title

Page

Pre-amplifier Impedance Matching for Cryogenic BPMs

347

P. Kowina, M. Freimuth, K. Gütlich, W. Kaufmann, H. Rödl, J. Wießmann
GSI, Darmstadt, Germany
N. Sobel, F. Völklein
Hochschule RheinMain, Wiesbaden, Germany

Beam Position Monitors (BPMs) for the FAIR fast-ramped super conducting synchrotron SIS-100 will be installed inside the cryostats of quadrupole magnets. This contribution focuses on the coupling path between BPM electrodes and low noise amplifiers installed outside the cryostat. Matching transformers (MT) meet well the requirements of reflection free signal transfer through the relative long lines without loading the capacitive BPM by 50 Ohm. Different transformers based on toroidal cores made out of Vitroperm-500F nanocrystalline were tested. The form of windings and circuit geometry were optimized to improve linearity allow for resonance-free transmission over a required frequency range from 0.1 MHz to 80 MHz. The MTs have to be balanced pair wise within 0.1 dB and the geometry of windings has to be mechanically stabilized using e.g. epoxy resin. A choice of different epoxy types and their suitability for cryogenic operation was tested in liquid Nitrogen and liquid Helium.

Poster TUPD20 [0.655 MB]

Paper	Title	Page
TUPD20	Pre-amplifier Impedance Matching for Cryogenic BPMs	347
	P. Kowina, M. Freimuth, K. Gütlich, W. Kaufmann, H. Rödl, J. Wießmann GSI, Darmstadt, Germany N. Sobel, F. Völklein Hochschule RheinMain, Wiesbaden, Germany
	Beam Position Monitors (BPMs) for the FAIR fast-ramped super conducting synchrotron SIS-100 will be installed inside the cryostats of quadrupole magnets. This contribution focuses on the coupling path between BPM electrodes and low noise amplifiers installed outside the cryostat. Matching transformers (MT) meet well the requirements of reflection free signal transfer through the relative long lines without loading the capacitive BPM by 50 Ohm. Different transformers based on toroidal cores made out of Vitroperm-500F nanocrystalline were tested. The form of windings and circuit geometry were optimized to improve linearity allow for resonance-free transmission over a required frequency range from 0.1 MHz to 80 MHz. The MTs have to be balanced pair wise within 0.1 dB and the geometry of windings has to be mechanically stabilized using e.g. epoxy resin. A choice of different epoxy types and their suitability for cryogenic operation was tested in liquid Nitrogen and liquid Helium.
	Poster TUPD20 [0.655 MB]