New Neutron Sensitive Beam Loss Monitor (nBLM)

International audienceThe beam loss detection is of the utmost importance for accelerator safety. At CEA, we are closely collaborating with ESS and DMCS on development of ESS nBLM. The system is based on Micromegas* gaseous detector sensitives to fast neutrons produced when beam particles hit the accelerator materials. This detector has powerful features: reliable neutron detection and fast time response. The nBLM control system provides slow monitoring, fast security based on neutron counting and post mortem data. It is fully handled by EPICS, which drives 3 different subsystems: a Siemens PLC regulates the gas line, a CAEN crate controls low and high voltages, and a MTCA system based on IOxOS boards is in charge of the fast data processing for 16 detectors. The detector signal is digitized by the 250 Ms/s ADC, which is further processed by the firmware developed by DMCS and finally retrieved and sent to EPICS network. For other accelerator projects, we are designing nBLM system close to ESS nBLM one. In order to be able to sustain the full control system, we are developing the firmware and the driver. This paper summarizes CEA’s work on the nBLM control system for the ESS and other accelerators

Neutron sensitive beam loss monitoring system for the European Spallation Source linac

International audienceThe European Spallation Source (ESS), currently under construction in Lund, Sweden, will be a neutron source based on a partly superconducting linac. The ESS linac will be accelerating protons to 2 GeV with a peak current of 62.5 mA and ultimately delivering a 5 MW beam to a rotating tungsten target for neutron production. For a successful tuning and operation of a linac, a beam loss monitoring (BLM) system is required. BLM systems are designed to protect the machine from beam-induced damage and unnecessary activation of the components. This paper focuses on one of the BLM systems to be deployed at the ESS linac, namely the neutron sensitive BLM (nBLM). An overview of the ESS nBLM system design will be presented. In addition to this, results of the tests performed with the full nBLM data acquisition chain will be discussed. These tests represent the first evaluation of the system prototype in a realistic environment. They served as an input to initial study of the procedure for neutron detection algorithm configuration discussed in this contribution as well