Measurement of Frequency Response of LBL Stochastic Cooling Arrays for TeV-I Storage Rings

摘要

Lawrence Berkeley Laboratory (LBL) has developed electrodes for the stochastic cooling system which is used in the anti-proton source in TeV-I at Fermilab. The electrodes are in the form of a pair of stripline couplers or loops, the elements of which are mounted on opposite sides of the beam. We have made two different couplers of similar design, the one to operate in the frequency range 1-2 GHz, the other, 2-4 GHz. We have made two different types of measurements; the one involving the response of a single loop pair to a wire signal simulating the beam signal; the other, the response of a 16 loop-pair array to an actual beam. Both sets of measurements were made in the frequency domain, and both involved taking both the so-called sum and difference responses, in which the signals from the two elements of the loop pair are added and subtracted, respectively. The former response shows little variation as the beam or wire is displaced from the midplane of the loop-pair; the latter exhibits a roughly linear variation with displacement, and is used to detect the position variation of the particles in cooling systems. In general, the beam and wire measurements were found to be in excellent agreement. (ERA citation 10:039780)