arXiv subjects

Richard Hall-Wilton

Publications and source records attributed to Richard Hall-Wilton.

22 records · Page 2Linked to original sources

arXiv2013

Geant4 based simulations for novel neutron detector development

A Geant4-based Python/C++ simulation and coding framework, which has been developed and used in order to aid the R&D efforts for thermal neutron detectors at neutron scattering facilities, is described. Built upon configurable geometry and generator modules, it integrates a general purpose object oriented output file format with meta-data, developed in order to facilitate a faster turn-around time when setting up and analysing simulations. Also discussed are the extensions to Geant4 which have been implemented in order to include the effects of low-energy phenomena such as Bragg diffraction in the polycrystalline support materials of the detector. Finally, an example application of the framework is briefly shown.

physics.ins-det↗

arXiv2013

Investigation of gamma-ray sensitivity of neutron detectors based on thin converter films

Currently, many detector technologies for thermal neutron detection are in development in order to lower the demand for the rare 3He gas. Gas detectors with solid thin film neutron converters readout by gas proportional counter method have been proposed as an appropriate choice for applications where large area coverage is necessary. In this paper, we investigate the probability for gamma-rays to generate a false count in a neutron measurement. Simulated results are compared to measurement with a 10B thin film prototype and a 3He detector. It is demonstrated that equal gamma-ray rejection to that of 3He tubes is achieved with the new technology. The arguments and results presented here are also applicable to gas detectors with converters other than solid 10B layers, such as 6Li layers and 10BF3 gas.

physics.ins-det↗

arXiv2012

Multi-Grid Boron-10 detector for large area applications in neutron scattering science

The present supply of 3He can no longer meet the detector demands of the upcoming ESS facility and continued detector upgrades at current neutron sources. Therefore viable alternative technologies are required to support the development of cutting-edge instrumentation for neutron scattering science. In this context, 10B-based detectors are being developed by collaboration between the ESS, ILL, and Linköping University. This paper reports on progress of this technology and the prospects applying it in modern neutron scattering experiments. The detector is made-up of multiple rectangular gas counter tubes coated with B4C, enriched in 10B. An anode wire reads out each tube, thereby giving position of conversion in one of the lateral co-ordinates as well as in depth of the detector. Position resolution in the remaining co-ordinate is obtained by segmenting the cathode tube itself. Boron carbide films have been produced at Linköping University and a detector built at ILL. The characterization study is presented in this paper, including measurement of efficiency, effects of the fill gas species and pressure, coating thickness variation on efficiency and sensitivity to gamma-rays.

physics.ins-det↗

arXiv2011

Design, Implementation and First Measurements with the Medipix Neutron Camera in CMS

The Medipix detector is the first device dedicated to measuring mixed-field radiation in the CMS cavern and able to distinguish between different particle types. Medipix2-MXR chips bump bonded to silicon sensors with various neutron conversion layers developed by the IEAP CTU in Prague were successfully installed for the 2008 LHC start-up in the CMS experimental and services caverns to measure the flux of various particle types, in particular neutrons. They have operated almost continuously during the 2010 run period, and the results shown here are from the proton run between the beginning of July and the end of October 2010. Clear signals are seen and different particle types have been observed during regular LHC luminosity running, and an agreement in the measured flux rate is found with the simulations. These initial results are promising, and indicate that these devices have the potential for further and future LHC and high energy physics applications as radiation monitoring devices for mixed field environments, including neutron flux monitoring. Further extensions are foreseen in the near future to increase the performance of the detector and its coverage for monitoring in CMS.

physics.ins-det↗