| 1. |
- Elter, Zsolt, 1987, et al.
(författare)
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Performance investigation of the pulse and Campbelling modes of a fission chamber using a Poisson pulse train simulation code
- 2015
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Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 774, s. 60-67
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Tidskriftsartikel (refereegranskat)abstract
- The detectors of the neutron flux monitoring system of the foreseen French GEN-IV sodium-cooled fast reactor (SFR) will be high temperature fission chambers placed in the reactor vessel in the vicinity of the core. The operation of a fission chamber over a wide-range neutron flux will be feasible provided that the overlap of the applicability of its pulse and Campbelling operational modes is ensured. This paper addresses the question of the linearity of these two modes and it also presents our recent efforts to develop a specific code for the simulation of fission chamber pulse trains. Our developed simulation code is described and its overall verification is shown. An extensive quantitative investigation was performed to explore the applicability limits of these two standard modes. It was found that for short pulses the overlap between the pulse and Campbelling modes can be guaranteed if the standard deviation of the background noise is not higher than 5% of the pulse amplitude. It was also shown that the Campbelling mode is sensitive to parasitic noise, while the performance of the pulse mode is affected by the stochastic amplitude distributions.
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| 2. |
- Elter, Zsolt, 1987
(författare)
-
pyFC: a TRIM-based fission chamber pulse shape simulator
- 2015
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report presents the code system pyFC (python-based simulation of Fission Chambers) which simulates the pulse creation in fission chambers. The current pulses in a fission chamber are generated due to the ionization of the filling gas by the heavy ion emitted from the neutron induced fission in the fissile deposit. In pyFC the path of the heavy ion and the spatial distribution of the charges emerging from the ionization process are simulated with the TRIM code, and the parameters of the charge collection between the electrodes are computed with the BOLSIG software. The coupling of the codes is done in Python.The report presents the physical and geometrical considerations implemented in pyFC and the verification of the code through comparison with the results of Chester, a CEA code for simulation of fission chambers.
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| 3. |
- Jammes, C., et al.
(författare)
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Progress in the development of the neutron flux monitoring system of the French GEN-IV SFR: Simulations and experimental validations
- 2015
-
Ingår i: 2015 4th International Conference on Advancements in Nuclear Instrumentation Measurement Methods and their Applications, ANIMMA 2015. - 9781479999187
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Konferensbidrag (refereegranskat)abstract
- The neutron flux monitoring system of the French GEN-IV sodium-cooled fast reactor will rely on high-temperature fission chambers installed in the reactor vessel and capable of operating over a wide-range neutron flux. The definition of such a system is presented and the technological solutions are justified with the use of simulation and experimental results. © 2015 IEEE.
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| 4. |
- Pazsit, Imre, 1948, et al.
(författare)
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Energy correlations of prompt fission neutrons in the laboratory frame
- 2015
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Ingår i: Mathematics and Computations, Supercomputing in Nuclear Applications and Monte Carlo International Conference, M and C+SNA+MC 2015, Nashville, United States, 19-23 April 2015. - 9781510808041 ; 2, s. 1158-1167
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Konferensbidrag (refereegranskat)abstract
- Correlations between the energies and emission angles of prompt fission neutrons are of significance for all methods which use the statistics of detection events for determining subcritical reactivity in reactor cores or for non-destructive assay of nuclear materials for safeguards purposes. There is no experimental knowledge available on the existence or properties of such correlations. Therefore, recently increasing attempts are made to determine these correlations from the properties of the fission process. One possible reason of such correlations between fission neutron energies and angles in the laboratory system is the fact that the prompt neutrons are emitted from the moving fission targets, even if their energies and emission angles are independent in the moving frame of the fission fragment. In this paper this concept is investigated analytically and through numerical simulations. It is shown that such correlations are due to the random properties (energy and direction of motion) of the fission fragments, and the magnitude of the covariance depends on the second order moments of the fission fragment parameters. Preliminary numerical simulations show that the correlations in energy, generated this way, are rather small.
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