Neutronics shielding analysis for the end plug of a tandem mirror fusion reactor

Magdi M H Ragheb, Charles W. Maynard

Research output: Contribution to journalArticle

Abstract

A neutronics analysis using the Monte Carlo method is carried out for the end-plug penetration and magnet system of a tandem mirror fusion reactor. Detailed penetration and the magnets' three-dimensional configurations are modeled. A method of position dependent angular source biasing is developed to adequately sample the DT fusion source in the central cell region and obtain flux contributions at the penetration components. To assure cryogenic stability, the barrier cylindrical solenoid is identified as needing substantial shielding of about 1 m of a steel-lead-boron-carbide-water mixture. Heating rates there would require a thermal-hydraulic design similar to that in the central cell blanket region. The transition coils, however, need a minimal 0.2 m thickness shield. The leakage neutron flux at the direct converters is estimated at 1.3×1015 n/(m2·s), two orders of magnitude lower than that reported at the neutral beam injectors for tokamaks around 1017 n/(m2·s) for a 1 MW/m2 14 MeV neutron wall loading. This result is obtained through a coupling between the nuclear and plasma physics designs in which hydrogen ions rather than deuterium atoms are used for energy injection at the end plug, to avoid creating a neutron source there. This lower and controllable radiation leakage problem is perceived as a potential major advantage of tandem mirrors compared to tokamaks and laser reactor systems.

Original languageEnglish (US)
Pages (from-to)367-380
Number of pages14
JournalJournal of Fusion Energy
Volume1
Issue number4
DOIs
StatePublished - Oct 1 1981

Fingerprint

mirror fusion
tandem mirrors
fusion reactors
Fusion reactors
plugs
Shielding
Magnets
shielding
Mirrors
penetration
Boron carbide
Neutron flux
Neutron sources
Solenoids
leakage
magnets
Deuterium
Heating rate
Cryogenics
boron carbides

Keywords

  • Monte Carlo method
  • fusion reactors
  • magnets
  • mathematical models
  • neutron transport
  • radiation transport
  • sampling
  • shielding
  • tandem mirror
  • transport theory

ASJC Scopus subject areas

  • Nuclear Energy and Engineering

Cite this

Neutronics shielding analysis for the end plug of a tandem mirror fusion reactor. / Ragheb, Magdi M H; Maynard, Charles W.

In: Journal of Fusion Energy, Vol. 1, No. 4, 01.10.1981, p. 367-380.

Research output: Contribution to journalArticle

@article{cd9f1efb19f54bd681f98eb8f6bb12b6,
title = "Neutronics shielding analysis for the end plug of a tandem mirror fusion reactor",
abstract = "A neutronics analysis using the Monte Carlo method is carried out for the end-plug penetration and magnet system of a tandem mirror fusion reactor. Detailed penetration and the magnets' three-dimensional configurations are modeled. A method of position dependent angular source biasing is developed to adequately sample the DT fusion source in the central cell region and obtain flux contributions at the penetration components. To assure cryogenic stability, the barrier cylindrical solenoid is identified as needing substantial shielding of about 1 m of a steel-lead-boron-carbide-water mixture. Heating rates there would require a thermal-hydraulic design similar to that in the central cell blanket region. The transition coils, however, need a minimal 0.2 m thickness shield. The leakage neutron flux at the direct converters is estimated at 1.3×1015 n/(m2·s), two orders of magnitude lower than that reported at the neutral beam injectors for tokamaks around 1017 n/(m2·s) for a 1 MW/m2 14 MeV neutron wall loading. This result is obtained through a coupling between the nuclear and plasma physics designs in which hydrogen ions rather than deuterium atoms are used for energy injection at the end plug, to avoid creating a neutron source there. This lower and controllable radiation leakage problem is perceived as a potential major advantage of tandem mirrors compared to tokamaks and laser reactor systems.",
keywords = "Monte Carlo method, fusion reactors, magnets, mathematical models, neutron transport, radiation transport, sampling, shielding, tandem mirror, transport theory",
author = "Ragheb, {Magdi M H} and Maynard, {Charles W.}",
year = "1981",
month = "10",
day = "1",
doi = "10.1007/BF01050302",
language = "English (US)",
volume = "1",
pages = "367--380",
journal = "Journal of Fusion Energy",
issn = "0164-0313",
publisher = "Springer New York",
number = "4",

}

TY - JOUR

T1 - Neutronics shielding analysis for the end plug of a tandem mirror fusion reactor

AU - Ragheb, Magdi M H

AU - Maynard, Charles W.

PY - 1981/10/1

Y1 - 1981/10/1

N2 - A neutronics analysis using the Monte Carlo method is carried out for the end-plug penetration and magnet system of a tandem mirror fusion reactor. Detailed penetration and the magnets' three-dimensional configurations are modeled. A method of position dependent angular source biasing is developed to adequately sample the DT fusion source in the central cell region and obtain flux contributions at the penetration components. To assure cryogenic stability, the barrier cylindrical solenoid is identified as needing substantial shielding of about 1 m of a steel-lead-boron-carbide-water mixture. Heating rates there would require a thermal-hydraulic design similar to that in the central cell blanket region. The transition coils, however, need a minimal 0.2 m thickness shield. The leakage neutron flux at the direct converters is estimated at 1.3×1015 n/(m2·s), two orders of magnitude lower than that reported at the neutral beam injectors for tokamaks around 1017 n/(m2·s) for a 1 MW/m2 14 MeV neutron wall loading. This result is obtained through a coupling between the nuclear and plasma physics designs in which hydrogen ions rather than deuterium atoms are used for energy injection at the end plug, to avoid creating a neutron source there. This lower and controllable radiation leakage problem is perceived as a potential major advantage of tandem mirrors compared to tokamaks and laser reactor systems.

AB - A neutronics analysis using the Monte Carlo method is carried out for the end-plug penetration and magnet system of a tandem mirror fusion reactor. Detailed penetration and the magnets' three-dimensional configurations are modeled. A method of position dependent angular source biasing is developed to adequately sample the DT fusion source in the central cell region and obtain flux contributions at the penetration components. To assure cryogenic stability, the barrier cylindrical solenoid is identified as needing substantial shielding of about 1 m of a steel-lead-boron-carbide-water mixture. Heating rates there would require a thermal-hydraulic design similar to that in the central cell blanket region. The transition coils, however, need a minimal 0.2 m thickness shield. The leakage neutron flux at the direct converters is estimated at 1.3×1015 n/(m2·s), two orders of magnitude lower than that reported at the neutral beam injectors for tokamaks around 1017 n/(m2·s) for a 1 MW/m2 14 MeV neutron wall loading. This result is obtained through a coupling between the nuclear and plasma physics designs in which hydrogen ions rather than deuterium atoms are used for energy injection at the end plug, to avoid creating a neutron source there. This lower and controllable radiation leakage problem is perceived as a potential major advantage of tandem mirrors compared to tokamaks and laser reactor systems.

KW - Monte Carlo method

KW - fusion reactors

KW - magnets

KW - mathematical models

KW - neutron transport

KW - radiation transport

KW - sampling

KW - shielding

KW - tandem mirror

KW - transport theory

UR - http://www.scopus.com/inward/record.url?scp=0019622884&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0019622884&partnerID=8YFLogxK

U2 - 10.1007/BF01050302

DO - 10.1007/BF01050302

M3 - Article

AN - SCOPUS:0019622884

VL - 1

SP - 367

EP - 380

JO - Journal of Fusion Energy

JF - Journal of Fusion Energy

SN - 0164-0313

IS - 4

ER -