Journal of Fusion Energy

, Volume 35, Issue 2, pp 142–147 | Cite as

A Neutron Diode for Subcritical Multistage Multipliers with Special Reference in Tritium Breeding

Review Article


In this paper the interaction between a magnetic field and the neutron spin magnetic moment is explored for use in the design of a neutron diode or valve that allows a neutron flux to pass in one direction, while preventing a neutron flux in the opposite direction. A neutron diode that ensures the unidirectional movement of neutrons could be used in the design of a subcritical multistage neutron multiplier, a device that has thus far not been realised. With a subcritical multistage neutron multiplier, an initial source of neutrons could be multiplied substantially in a very small area. Such a device could have potential applications in tritium breeding in a fusion reactor, in medicine, in space exploration, etc. Utilizing a simplified geometrical model, a first preliminary study is performed to assess the feasibility of this concept.


Subcritical multistage multiplier Neutronic flux Tritium breeding 

List of symbols





\({\mathbf {B}} \)

Magnetic field

\(E_n \)

Energy of the neutron



\(^3H \)

Rate of tritium breeding



\(m_n \)

Mass of the neutron

\(M_n \)

n-Stage subcritical multiplication factor

\(M_1 \)

Single-stage subcritical multiplication factor


Number of stages






x-axis coordinate

\(X_1 \)

Displacement in x-direction


z-axis coordinate

\(Z_1 \)

Displacement in z-direction

Greek symbols

\(\epsilon \)

Loss factor

\(\theta \)

Angular separation

\(\kappa \)

Neutron multiplication factor

\(\mu _{S_{z}} \)

Spin-magnetic momentum of the neutron

\(\Phi \)

Neutronic flux from fusion core

Subscripts symbols






n stages


One stage


  1. 1.
    L. Borst, The convergatron, a neutron amplifier. Phys. Rev. 107, 905–906 (1957)ADSCrossRefGoogle Scholar
  2. 2.
    R. Avery, Coupled reactors with suppressed feedback. in Proceedings of 2nd UN International Conference, Geneva, vol. 12, pp. 182–191 (1958)Google Scholar
  3. 3.
    H. Daniel, Y.V. Petrov, Subcritical fission reactor driven by the low power accelerator. Nucl. Instrum. Meth. A 373, 131–134 (1996)ADSCrossRefGoogle Scholar
  4. 4.
    A.P. Barzilov, A.V. Gulevich, A.V. Zrodnikov, O.F. Kukharchuk, V.B. Polevoy, L.P. Feoktistov, Neutronics analysis for a coupled blanket system of the hybrid fission-fusion reactor. Institute for Physics and Power Engineering Technical Report IPPE-2522 (1996)Google Scholar
  5. 5.
    A.M. Degtyarev, A.K. Kalugin, L.I. Ponomarev, Cascade subcritical molten salt reactor (CSMSR): Main features and restrictions. Prog. Nucl. Energy 47, 99–105 (2005)CrossRefGoogle Scholar
  6. 6.
    A. Gulevich, V. Chekunov, O. Fokina, O. Komlev, O. Kukharchuk, C. Melnikov, N. Novikova, L. Ponomarev, E. Zemskov, Concept of electron accelerator-driven system based on subcritical cascade reactor. Prog. Nucl. Energy 50, 347–352 (2008)CrossRefGoogle Scholar
  7. 7.
    A. Clausse, L. Soto, C. Friedli, L. Altamirano, Feasibility study of a hybrid subcritical fission system driven by Plasma-Focus fusion neutrons. Ann. Nucl. Energy 78, 10–14 (2015)CrossRefGoogle Scholar
  8. 8.
    H. Nifenecker, O. Meplan, S. David, Accelerator Driven Subcritical Reactors (Institute of Physics Publishing, Bristol, 2003)CrossRefGoogle Scholar
  9. 9.
    J.T. Cremer, D.L. Williams, M.J. Fuller, C.K. Gary, M.A. Piestrup, R.H. Pantell, J. Feinstein, R.G. Flocchini, M. Boussoufi, H.P. Egbert, M.D. Kloh, R.B. Walker, Periodic magnetic field as a polarized and focusing thermal neutron spectrometer and monochromator. Rev. Sci. Instrum. 81(1), 013902 (2010)ADSCrossRefGoogle Scholar
  10. 10.
    J. Beringer, Particle Data Group, 2013 review of particle physics. Phys. Rev. D 86, 010001 (2012)ADSCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  1. 1.Department of EngineeringUniversity of CambridgeCambridgeUK
  2. 2.Department of Applied PhysicsUniversity of CadizPuerto RealSpain

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