Journal of Nuclear Science, Engineering and Technology (JONSAT)
In cooperation with the Iranian Nuclear Society

Design and construction of a neutron chopper and using the time-of -flight method for thermal neutron spectroscopy

Document Type : Research Paper

Authors

A. Omidi 1
M. Tajik 1
E. Bayat 2

1 Department of Nuclear Physics, Faculty of Physics, Damghan University, P.O.Box: 31716-41167, Damghan - Iran

2 Department of Physics, Faculty of Science, University of Birjand, P.O.Box: 97175-615, Birjand - Iran

https://doi.org/10.24200/nst.2024.1544.2007
Abstract
In this study, the design and construction of the neutron velocity selector were investigated. Theoretical and experimental studies have shown that it is preferable to construct the blades and the main shaft of the device from carbon fibers to reduce weight, prevent imbalance, and improve performance at high speeds. After designing the other components of the device, manufacturing the parts, and assembling the device, the vacuum system was tested, measuring a vacuum pressure of 3×10-2 millibars.  In the next phase, the device was mechanically tested at various speeds between 3000 and 11000 rpm, confirming the mechanical stability of the device. The measurement of selected thermal neutrons was carried out using neutrons from a 252Cf source. The experimental results show that this device is suitable for measuring the energy of neutrons in the range of less than 0.001 eV. This device requires a high-speed motor with a rotational speed of approximately 35,000 rpm and a high-resolution encoder to allow the passage of thermal neutrons with an energy of 0.025 eV, in order to reduce the error in time-of-flight measurements to an acceptable level.

Highlights

  1. Lu J, Sabharwall P, Heidrich B, Christensen R. Advanced Manufacturing and Instrumentation for Neutron Chopper Design. Journal of Young Investigators. 2020 Dec 1;38(6).

 

  1. Soldner T. Neutron Optics. Fundamental Neutron Physics Summer School 2015, University of Tennessee.

 

  1. Pesente S, Lunardon M, Nebbia G, Viesti G. Detection of Improvised Explosives Devices (IED) by using Tagged Neutron Beams. In Detection and disposal of improvised explosives. Dordrecht: Springer Netherlands. 2006 Jun 5;69-85.

 

  1. Mobley C.M. The construction of a Fermi neutron chopper for cross section measurements. 1966.

 

  1. Crawford R.K. Neutron scattering instrumentation. A guide to future directions. 2001.

 

  1. Gholamzadeh Z, Mirvakili S.M. Neutron powder diffractometry. Tehran: Aindeh-Saz Publishing. 2019 [In Persian].

 

  1. Madadi Sh, Pazirandeh A. Design and construction of neutron cutter and measurement of thermal neutron spectrum. Tehran: University of Tehran. 1998 [In Persian].

 

  1. Moeini Roodbally H, Hosseini A.S. Simulation of multi-blade neutron velocity selector using Mcstas software. Tehran: Sharif University of Technology. 1397 [In Persian].

 

  1. Lowde R.D. The principles of mechanical neutron-velocity selection. Journal of Nuclear Energy. Part A. Reactor Science. 1960 Feb 1;11(2-4):69-80.

 

  1. Kabir M.R. The development of manganite-based materials for thermoelectric power generation. Doctoral dissertation, UNSW Sydney.

 

  1. Grenci N, Cortes D, Flaska M. Design of an epithermal neutron velocity selection system for the Penn State Breazeale Reactor. Journal of Instrumentation. 2023 Jun 29;18(06):P06035.

 

  1. Lowde R.D. The principles of mechanical neutron-velocity selection. Journal of Nuclear Energy. Part A. Reactor Science. 1960 Feb 1;11(2-4):69-80.

 

  1. Bacon G.E. X-Ray and Neutron Diffraction: The Commonwealth and International Library: Selected Readings in Physics. Elsevier. 2013 Sep 3.

 

  1. Solidworks: Engineering 4.0. www.tecnetinc.com. Retrieved September 5, 2023.

 

  1. Omidi A, Tajik M, Bayat E. Investigation of the type of material and coating of neutron chopper blades on the amount of thermal neutron absorption. Journal of Research on Many-body Systems. 2024;14(2):27-36 [In Persian].

 

  1. Appel M, Frick B, Magerl A. A flexible high speed pulse chopper system for an inverted neutron time-of-flight option on backscattering spectrometers. Scientific Reports. 2018 Sep 11;8(1):13580.

 

17. Lin C.M. Parameter optimisation of a vacuum plasma spraying process using boron carbide. Journal of Thermal Spray Technology. 2012 Sep;21:873-81.

Keywords

Neutron velocity selector
Thermal neutron
252Cf source
Time of flight
  1. Lu J, Sabharwall P, Heidrich B, Christensen R. Advanced Manufacturing and Instrumentation for Neutron Chopper Design. Journal of Young Investigators. 2020 Dec 1;38(6).

 

  1. Soldner T. Neutron Optics. Fundamental Neutron Physics Summer School 2015, University of Tennessee.

 

  1. Pesente S, Lunardon M, Nebbia G, Viesti G. Detection of Improvised Explosives Devices (IED) by using Tagged Neutron Beams. In Detection and disposal of improvised explosives. Dordrecht: Springer Netherlands. 2006 Jun 5;69-85.

 

  1. Mobley C.M. The construction of a Fermi neutron chopper for cross section measurements. 1966.

 

  1. Crawford R.K. Neutron scattering instrumentation. A guide to future directions. 2001.

 

  1. Gholamzadeh Z, Mirvakili S.M. Neutron powder diffractometry. Tehran: Aindeh-Saz Publishing. 2019 [In Persian].

 

  1. Madadi Sh, Pazirandeh A. Design and construction of neutron cutter and measurement of thermal neutron spectrum. Tehran: University of Tehran. 1998 [In Persian].

 

  1. Moeini Roodbally H, Hosseini A.S. Simulation of multi-blade neutron velocity selector using Mcstas software. Tehran: Sharif University of Technology. 1397 [In Persian].

 

  1. Lowde R.D. The principles of mechanical neutron-velocity selection. Journal of Nuclear Energy. Part A. Reactor Science. 1960 Feb 1;11(2-4):69-80.

 

  1. Kabir M.R. The development of manganite-based materials for thermoelectric power generation. Doctoral dissertation, UNSW Sydney.

 

  1. Grenci N, Cortes D, Flaska M. Design of an epithermal neutron velocity selection system for the Penn State Breazeale Reactor. Journal of Instrumentation. 2023 Jun 29;18(06):P06035.

 

  1. Lowde R.D. The principles of mechanical neutron-velocity selection. Journal of Nuclear Energy. Part A. Reactor Science. 1960 Feb 1;11(2-4):69-80.

 

  1. Bacon G.E. X-Ray and Neutron Diffraction: The Commonwealth and International Library: Selected Readings in Physics. Elsevier. 2013 Sep 3.

 

  1. Solidworks: Engineering 4.0. www.tecnetinc.com. Retrieved September 5, 2023.

 

  1. Omidi A, Tajik M, Bayat E. Investigation of the type of material and coating of neutron chopper blades on the amount of thermal neutron absorption. Journal of Research on Many-body Systems. 2024;14(2):27-36 [In Persian].

 

  1. Appel M, Frick B, Magerl A. A flexible high speed pulse chopper system for an inverted neutron time-of-flight option on backscattering spectrometers. Scientific Reports. 2018 Sep 11;8(1):13580.

 

17. Lin C.M. Parameter optimisation of a vacuum plasma spraying process using boron carbide. Journal of Thermal Spray Technology. 2012 Sep;21:873-81.

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