Optimization of beam intensity measurement system of HIPA at PSI

Beam intensity measurement of high intensity proton accelerator at PSI mainly consists of several passive cavity type monitors and corresponding electronics. New VME based electronics are running in parallel for final online testing with the old CAMAC ones, which will be replaced soon. The new pre-amplifier of the VME system is suffering significant temperature-dependent drift, leading to an inaccurate measurement. Further, wrong transmission rate may lead to unexpected interlock and beam losses during operation. To address this issue many temperature compensation schemes were considered, numerous lab tests were conducted, eventually reach a temperature stabilization solution. Experimental validation demonstrates a factor of 4 reduction in temperature-induced measurement variance compared to previous implementation, achieving a temperature coefficient 166 ppm/degree for RF test signal. Furthermore, the new electronics incorporate a phase measurement of the 50.6 MHz proton bunches for beam energy monitoring. Beam tests show energy measurement consistency within ±0.15%. This implementation greatly facilitates the commissioning and status monitoring of the accelerator.