Study on a beam orbit in heavy ion cooler synchrotron, TARN 2 and development of high sensitivity beam position monitor for its compensation

In this study, from requirements on low intensity beam position measurement, by clearly aiming at realizing BPM with high sensitivity and low noise, a signal induced at a pick-up by a beam was amplified as much as possible, to follow a technology to reduce the noise as much as possible. As a result, an actual use development of a head amplifier with high impedance and low input conversion noise was at first succeeded to realize upgrading of high sensitivity of BPM by using with a spectrum-analyzer with high sensitivity. As a result of development, even when current value of a going-around beam was 1 μA it became possible to measure the beam position at 0.3 mm in accuracy. A numerical analysis on the noise of beam signal and head amplifier in this study is much effective for development of BPM with high sensitivity and low noise aiming at position measurement of low intensity beam, and largely contributes to the beam physics and accelerator technology. (G.K.)