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Numerical Investigation of a UCN Source Based on Solid Deuterium by Combining a Simulation Code with an Analytical Approach

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DOI: 10.4236/jmp.2014.517179    3,361 Downloads   3,672 Views  

ABSTRACT

At thermal ultra-cold neutron (UCN) sources (neutrons in thermal equilibrium with the moderator) only a very small fraction of neutrons have velocities ~6 m/s. Therefore, the UCN production rate cannot be substantially increased by simply lowering the temperature of the moderator. The new approach is to use the super-thermal principle, i.e., neutrons not in thermal equilibrium with the converter. We want to investigate scattering kernels for a super-thermal UCN source based on a two-layer arrangement of D2O and solid D2. The solid D2 (sD2) at temperature 8 K is kept in close contact with D2O moderator at room temperature. Using the MCNP code, the fast neutron flux on the spallation target, the thermal flux in the D2O near the sD2, and the cold flux in the sD2 are simulated. For a given cold flux, neutron transport equations are calculated. In order to obtain precise neutron scattering kernels, and consequently UCN flux and density, 330 neutron energy groups have been taken. The coupled energy dependent transport equations have been solved by combining MCNPX code with an analytical approach and using implicit method in MATLAB. We have obtained an optimal dimension for the UCN source. A suitable space step has been taken for the numerical stability.

Conflicts of Interest

The authors declare no conflicts of interest.

Cite this paper

Mohammadi, H. , Firoozabadi, M. and Gheisari, R. (2014) Numerical Investigation of a UCN Source Based on Solid Deuterium by Combining a Simulation Code with an Analytical Approach. Journal of Modern Physics, 5, 1831-1838. doi: 10.4236/jmp.2014.517179.

References

[1] Ignatovich, V.K. (1990) Ultracold Neutrons. Clarendon Press, Oxford.
[2] Golub, R., Richardson, D.J. and Lamoreaux, S.K. (1991) Ultra-Cold Neutrons. Hilger, Bristol.
[3] Steyerl, A., et al. (1986) Physics Letters A, 116, 347.
http://dx.doi.org/10.1016/0375-9601(86)90587-6
[4] Golub, R. and Pendlebury, J.M. (1977) Physics Letters A, 62, 337.
http://dx.doi.org/10.1016/0375-9601(77)90434-0
[5] Brome, C.R., Butterworth, J.S., Dzhosyuk, S.N., Mattoni, C.E.H., McKinsey, D.N., et al. (2001) Physical Review C, 63, Article ID: 055502.
http://dx.doi.org/10.1103/PhysRevC.63.055502
[6] Masuda, Y., Kitagaki, T., Hatanaka, K., Higuchi, M., Ishimoto, S., et al. (2002) Physical Review Letters, 89, Article ID: 284801.
http://dx.doi.org/10.1103/PhysRevLett.89.284801
[7] Zimmer, O., Baumann, K., Fertl, M., Franke, B., Mironov, S., et al. (2007) Physical Review Letters, 99, Article ID: 104801.
http://dx.doi.org/10.1103/PhysRevLett.99.104801
[8] Serebrov, A.P. (2000) Nuclear Instruments and Methods in Physics Research Section A, 440, 653.
http://dx.doi.org/10.1016/S0168-9002(99)01057-8
[9] Saunders, A., Anaya, J.M., Bowles, T.J., Filippone, B.W., Geltenbort, P., et al. (2004) Physics Letters B, 593, 55.
http://dx.doi.org/10.1016/j.physletb.2004.04.048
[10] Atchison, F., Blau, B., Bodek, K., Van den Brandt, B., Brys, T., et al. (2009) Nuclear Instruments and Methods in Physics Research Section A, 611, 252.
http://dx.doi.org/10.1016/j.nima.2009.07.072
[11] Frei, A., Gutsmiedl, E., Morkel, C., Muller, A.R., Paul, S. and Urban, M. (2009) Physical Review B, 80, Article ID: 064301.
http://dx.doi.org/10.1103/PhysRevB.80.064301
[12] Atchsion, F., Blau, B., Bodek, K., Van den Brandt, B., Brys, T. and Fierlinger, P. (2007) Physical Review Letters, 99, Article ID: 262502.
http://dx.doi.org/10.1103/PhysRevLett.99.262502
[13] Altarev, I., Daum, M., Frei, A., Gutsmiedl, E., Hampel, G., Hartmann, F.J., et al. (2008) The European Physical Journal A, 37, 9-14.
http://dx.doi.org/10.1140/epja/i2008-10604-8
[14] Sekimoto, H. (2007) Nuclear Reactor Theory. Tokyo Institute of Technology Press, Tokyo.
[15] Atchsion, F., Blau, B., Bodek, K., Van den Brandt, B., Brys, T., Fierlinger, P., et al. (2005) Physical Review Letters, 95, Article ID: 182502.
http://dx.doi.org/10.1103/PhysRevLett.95.182502
[16] MacFarlane, R.E. and Muir, D.W. (1994) The NJOY Nuclear Data Processing Systems Version 91, LA-12740-M. Los Alamos National Laboratory, Los Alamos.
[17] Kasprzak, M. (2004) Thermal Up-Scattering of Very Cold and Ultra-Cold Neutrons in Solid Deuterium. Master’s Thesis, Jagiellonian University Press, Krakow.
[18] Frei, A., Gutsmiedl, E., Morkel, C., Muller, A.R., Paul, S., Rols, S., et al. (2010) Europhysics Letters, 92, Article ID: 62001.
http://dx.doi.org/10.1209/0295-5075/92/62001
[19] Kasprzak, M. (2008) Ultra-Cold Neutron Converters. Ph.D. Thesis, University of Vienna, Vienna.
[20] Atchsion, F., Van den Brandt, B., Brys, T., Fierlinger, P., Hautle, P., Henneck, R., et al. (2005) Physical Review C, 71, Article ID: 054601.
http://dx.doi.org/10.1103/PhysRevC.71.054601
[21] The PSI UCN Website:
http://ucn.web.psi.ch/
[22] Atchison, F. (2002) Internal Report, TM-14-02-02, Part I and II.

  
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