High energy particle background at neutron spallation sources and possible solutions

International Workshop on Neutron Optics and Detectors

Cherkashyna, N.^1 ; Kanaki, K.^1 ; Kittelmann, T.^1 ; Filges, U.^2 ; Deen, P.^1 ; Herwig, K.^3 ; Ehlers, G.^4 ; Greene, G.^5 ; Carpenter, J.^6 ; Connatser, R.^1 ; Hall-Wilton, R.^1,7 ; Bentley, P.M.^1,8

European Spallation Source ESS AB, 221 00 Lund, Sweden^1

Paul Scherrer Institute, 5232 Villigen PSI, Switzerland^2

Instrument and Source Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States^3

Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States^4

Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States^5

Argonne National Laboratory, Argonne, IL 60439, United States^6

Department of Electronics, Mid Sweden University, Sundsvall, Sweden^7

Department of Physics and Astronomy, Uppsala University, Uppsala 751 05, Sweden^8

关键词: Absorption characteristics;    Background suppression;    European spallation sources;    Hadronic calorimeters;    High-energy particles;    Low-energy particles;    Neutron spallation sources;    Spallation neutron sources;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/528/1/012013/pdf
DOI  :  10.1088/1742-6596/528/1/012013

来源: IOP

【 摘 要 】

Modern spallation neutron sources are driven by proton beams ∼ GeV energies. Whereas low energy particle background shielding is well understood for reactors sources of neutrons (∼20 MeV), for high energies (100s MeV to multiple GeV) there is potential to improve shielding solutions and reduce instrument backgrounds significantly. We present initial measured data on high energy particle backgrounds, which illustrate the results of particle showers caused by high energy particles from spallation neutron sources. We use detailed physics models of different materials to identify new shielding solutions for such neutron sources, including laminated layers of multiple materials. In addition to the steel and concrete, which are used traditionally, we introduce some other options that are new to the neutron scattering community, among which there are copper alloys as used in hadronic calorimeters in high energy physics laboratories. These concepts have very attractive energy absorption characteristics, and simulations predict that the background suppression could be improved by one or two orders of magnitude. These solutions are expected to be great benefit to the European Spallation Source, where the majority of instruments are potentially affected by high energy backgrounds, as well as to existing spallation sources.