Firmware and Software Implementation Status of the ICBLM and nBLM Systems for the ESS Facility

Abstract

The European Spallation Source (ESS) is a neutron source powered by a 5 MW, 2 GeV superconducting proton linac which is currently being constructed in Lund. Due to high beam current, just a few microseconds of operation with a misaligned beam can melt the accelerating cavity wall. Therefore, a Beam Loss Monitor (BLM) system is necessary to protect hardware and personnel from the consequences of beam loss. The BLM’s main function is to inhibit beam production when excessively high beam losses are detected. Besides protection functionality, the system is anticipated to provide the means to monitor the beam losses during all modes of operation with the objective of preventing excessive machine activation. This paper concentrates on implementation for ionization chamber Beam Loss Monitor (ICBLM) and Neutron Sensitive Beam Loss Monitor (nBLM) systems. The required microsecond reaction time has been achieved due to the application of an FPGA. A single detector module was installed and successfully tested at LINAC4 at CERN, in the section where conditions are similar to the ones expected in the ESS linac. The summary of these tests is also included.