Selective data analysis for diamond detectors in neutron fields

Detectors based on synthetic chemical vapor deposition diamond gain importance in various neutron applications. The superior thermal robustness and the excellent radiation hardness of diamond as well as its excellent electronic properties make this material uniquely suited for rough environments, such as nuclear fission and fusion reactors. The intrinsic electronic properties of single-crystal diamond sensors allow distinguishing various interactions in the detector. This can be used to successfully suppress background of γ-rays and charged particles in different neutron experiments, such as neutron flux measurements in thermal nuclear reactors or cross-section measurements in fast neutron fields. A novel technique of distinguishing background reactions in neutron experiments with diamond detectors will be presented. A proof of principle will be given on the basis of experimental results in thermal and fast neutron fields

Diamond Monitor Based Beam Loss Measurements in the LHC

Two pCVD Diamond based Beam Loss Monitors (dBLM) are installed near the primary collimators of the LHC, with a dedicated, commercial readout-system used to acquire their signals. The system is simultaneously able to produce a high sampling rate waveform and provide a real-time beam loss histogram for all bunches in the machine. This paper presents the data measured by the dBLM system during LHC beam operation in 2016

Selective data analysis for diamond detectors in neutron fields

Detectors based on synthetic chemical vapor deposition diamond gain importance in various neutron applications. The superior thermal robustness and the excellent radiation hardness of diamond as well as its excellent electronic properties make this material uniquely suited for rough environments, such as nuclear fission and fusion reactors. The intrinsic electronic properties of single-crystal diamond sensors allow distinguishing various interactions in the detector. This can be used to successfully suppress background of γ-rays and charged particles in different neutron experiments, such as neutron flux measurements in thermal nuclear reactors or cross-section measurements in fast neutron fields. A novel technique of distinguishing background reactions in neutron experiments with diamond detectors will be presented. A proof of principle will be given on the basis of experimental results in thermal and fast neutron fields

Experimental Results from the Characterization of Diamond Particle Detectors with a High Intensity Electron Beam

Understanding the sources of ultra-fast failures, with durations of less than 3 LHC turns, is important for a safe operation of the LHC, as only passive protection is possible in these time scales. Diamond particle detectors with bunch-by-bunch resolution and high dynamic range have been successfully used to improve the understanding of some new ultra-fast loss mechanisms discovered in the LHC. To fully exploit their potential, diamond detectors were characterized with a high-intensity electron beam (10⁵ to 1010 electrons per shot). For the first time their efficiency and linearity has been measured in such a wide range of intensities. In this paper the experimental setup will be described and the signals of the different detectors will be discussed. Finally, future applications of these detectors in high-radiation applications will be discussed

Response of Polycrystalline Diamond Particle Detectors Measured with a High Intensity Electron Beam

Comprehensive understanding of beam losses in the LHC is required to ensure full machine protection and efficient operation. The existing BLM system using ionization chambers is not adequate to resolve losses with a time resolution below some 10 us. Ionization chambers are also not adequate to measure very large transient losses, e.g. beam impacting on collimators. Diamond particle detectors with bunch-by-bunch resolution have therefore been used in LHC to measure fast particle losses with a time resolution down to a level of single bunches. Diamond detectors have also successfully been used for material damage studies in other facilities, e.g. HiRadMat at the CERN-SPS. To fully understand their potential, such detectors were characterized with an electron beam at the BTF in LNF INFN Italy, with bunch intensities from 10³ to 10⁹ electrons. The detector response and efficiency has been measured with a 50 Ω and a 1 Ω read-out system. This paper describes the experimental setup and the results of the experiment. In particular, the responses of three samples of 100 um single-crystalline diamond detectors and two samples of 500 um polycrystalline diamond detectors are presented

Beam Loss Monitors for the Cryogenic LHC Magnets

The Beam Loss Monitoring system of the Large Hadron Collider close to the interaction points contains mostly gas ionization chambers working at room temperature, located far from the superconducting coils of the magnets. The system records particles lost from circulating proton beams, but is also sensitive to particles coming from the experimental collisions, which do not contribute significantly to the heat deposition in the superconducting coils. In the future, with beams of higher brightness resulting in higher luminosity, distinguishing between these interaction products and dangerous quench-provoking beam losses from the circulating beams will be difficult. It is proposed to optimise by locating beam loss monitors inside the cold mass of the magnets, housing the superconducting coils, in a superfluid helium environment, at 1.9 K. This contribution will present results of radiation hardness test of p⁺-n-n+ silicon detectors which, together with single crystal Chemical Vapour Deposition diamond, are the main candidates for these future cryogenic beam loss monitors

Design of a Laser-based Profile Monitor for LINAC4 Commissioning at 50 MeV and 100 MeV

A laser-based profile monitor has been designed for commissioning of CERN's LINAC4 accelerator at 50 MeV and 100 MeV, as part of the development of a non-destructive profile and emittance monitor foreseen for the final 160 MeV beam. The system is based on a low power laser which is scanned through the H⁻ beam. Electrons, which are photo-detached from the ions by the laser, are deflected by a steerer magnet and measured by a diamond detector. The custom designed diamond detector is tailored to minimize the disturbance due to the electromagnetic field of the passing main beam. The laser source will be installed in the LINAC4 Klystron gallery located 75 m away from the profile station and an optical fiber will transport the laser to the tunnel. The laser propagation for different pulse length and peak power values was characterized with laboratory tests with such a long fiber. In this paper we describe the overall design, focusing on key elements such as the fiber-based laser transport and the electron detection with the diamond detector