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Title: A high-frequency Schottky detector for use in the Tevatron

Conference ·
OSTI ID:5633031

A vexing problem associated with detection of Schottky signals from a bunched beam is the presence of the coherent signal, which can be 10 or more orders of magnitude greater than the Schottky signal. To overcome this difficulty, we have constructed a Schottky detector for the Tevatron collider in the form of a high-Q ({approx}5000) resonant cavity which operates at roughly 2 GHz, well above the frequency at which the single-bunch frequency spectrum begins to roll off ({approx}200--300 MHz for the Tevatron). The detector is capable of sensing independently the vertical and horizontal particle motions. The 2 GHz Schottky signals are down-converted to frequencies below 100 kHz to permit relatively rapid high-resolution analysis using a FFT spectrum analyzer. The initial installation consists of a single cavity; a second detector will be built which employs a pair of phased cavities to permit discrimination between p's and {bar p}'s. Details of the design of both the cavity and the associated electronics are presented. Spectra obtained from the detector show clearly observable Schottky betatron lines, free of coherent contaminants; also seen are the common-mode'' longitudinal signals due to the offset of the beam from the detector center. The latter signals indicate that at 2 GHz, the coherent single-bunch spectrum from the detector is reduced by >80 dB; therefore, in normal collider operation, the Schottky betatron lines are essentially entirely free of coherent contaminants. Experimental data will be presented showing how the detector spectra can be used to measure such properties as transverse emittance and synchrotron frequency. 3 refs., 4 figs., 5 tabs.

Research Organization:
Lawrence Berkeley Lab., CA (USA)
Sponsoring Organization:
USDOE; USDOE, Washington, DC (USA)
DOE Contract Number:
AC03-76SF00098
OSTI ID:
5633031
Report Number(s):
LBL-29701; CONF-9010267-5; ON: DE91012354
Resource Relation:
Conference: 1990 workshop on accelerator instrumentation, Batavia, IL (USA), 1-4 Oct 1990
Country of Publication:
United States
Language:
English