Neutron ionization chambers

Grosshoeg, G.

doi:10.1016/0029-554x(79)90710-9

Cited by 20 publications

(5 citation statements)

References 145 publications

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“…The 10 B(n,α) 7 Li reaction is mostly used as a neutron converting reaction in combination with proportional counters or ionization chambers [104]. The use as an absolute flux monitor is limited due to the complexity to determine the area density of the 10 B layers with a high accuracy [105].…”

Section: B Neutron Flux Measurementsmentioning

confidence: 99%

Determination of Resonance Parameters and their Covariances from Neutron Induced Reaction Cross Section Data

Schillebeeckx

Becker

Danon

et al. 2012

Nuclear Data Sheets

119

142

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Section: B Neutron Flux Measurementsmentioning

confidence: 99%

Determination of Resonance Parameters and their Covariances from Neutron Induced Reaction Cross Section Data

Schillebeeckx

Becker

Danon

et al. 2012

Nuclear Data Sheets

119

142

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“…in the energy range from tens of keV to a few MeV [50]. Neutrons entering such detectors interact with the 3 He gas through the exothermic reaction:…”

Section: Introductionmentioning

confidence: 99%

Results from the TARC experiment: spallation neutron phenomenology in lead and neutron-driven nuclear transmutation by adiabatic resonance crossing

Abánades

Aleixandre

Andriamonje

et al. 2002

Nuclear Instruments and Methods in Physics Research Section A:

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We summarize here the results of the TARC experiment whose main purpose is to demonstrate the possibility of using Adiabatic Resonance Crossing (ARC) to destroy efficiently Long-Lived Fission Fragments (LLFFs) in accelerator-driven systems and to validate a new simulation developed in the framework of the Energy Amplifier programme. An experimental set-up was installed in a CERN PS proton beam line to study how neutrons produced by spallation at relatively high energy ( E n ≥ 1 MeV) slow down quasi adiabatically with almost flat isolethargic energy distribution and reach the capture resonance energy of an element to be transmuted where they will have a high probability of being captured. Precision measurements of energy and space distributions of spallation neutrons (using 2.5 GeV/ c and 3.5 GeV/ c protons) slowing down in a 3.3 m × 3.3 m × 3 m lead volume and of neutron capture rates on LLFFs 99 Tc, 129 I, and several other elements were performed. An appropriate formalism and appropriate computational tools necessary for the analysis and understanding of the data were developed and validated in detail. Our direct experimental observation of ARC demonstrates the possibility to destroy, in a parasitic mode, outside the Energy Amplifier core, large amounts of 99 Tc or 129 I at a rate exceeding the production rate, thereby making it practical to reduce correspondingly the existing stockpile of LLFFs. In addition, TARC opens up new possibilities for radioactive isotope production as an alternative to nuclear reactors, in particular for medical applications, as well as new possibilities for neutron research and industrial applications.

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“…Note the difference between the (D)T and ͑He 3 ͒DT cases, the latter producing neutrons by thermal reaction with T i ഠ 13 keV. The spectrometer [9] views the plasma vertically, and so the broadening is mainly from the fast ion gyromotion. The (D)T data are fitted with an anisotropic Maxwellian deuteron distribution with the perpendicular ͑T Ќ ͒ and parallel ͑T k ͒ temperatures as parame- ters.…”

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confidence: 98%

D-T Fusion with Ion Cyclotron Resonance Heating in the JET Tokamak

Start¹,

Jacquinot²,

Bergeaud³

et al. 1998

Phys. Rev. Lett.

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Ion cyclotron resonance heating (ICRH) experiments have been carried out in JET D-T plasmas using scenarios applicable to reactors. Deuterium minority heating in tritium plasmas is used for the first time and produces 1.66 MW of D-T fusion power for an ICRH power of 6 MW. The Q value is 0.22, which is a record for steady state discharges. Fundamental He 3 minority ICRH, in both 50:50 D-T and tritium dominated plasmas, generates strong bulk ion heating and ion temperatures up to 13 keV. Second harmonic tritium ICRH is seen to heat mainly the electrons as expected for JET conditions. All three schemes produce H-mode plasmas. [S0031-9007(98)06143-2] PACS numbers: 52.50. Gj, 52.55.Fa, 52.55.Pi Ion cyclotron resonance heating is the only method of heating majority ions, rather than electrons, in the dense core of a tokamak reactor. Radiofrequency (rf) power is used to excite a fast magnetosonic wave, to which the high density plasma is accessible. The wave is absorbed at a cyclotron resonance which is positioned in major radius (usually the plasma center) by the choice of magnetic field and rf frequency. The ions damping the wave are often accelerated to suprathermal energies, especially if they are a minority species. This energy is then transferred to the thermal ions and electrons by Coulomb collisions. If the energy of the absorbing ions is less than a critical value, power flows mainly to the thermal ions rather than to the electrons. The critical energy at which the power to the electrons equals that to the ions is given [1] by E crit 14.8AT e ͓Sn j Z 2 j ͞n e A j ͔ 2͞3 where A is the atomic mass of the energetic ions, n e is the electron density, Z is the atomic number, the sum is over the thermal ion species, and T e is the electron temperature. For fast deuterons in a tritium plasma, E crit 14.2T e . In the JET D-minority experiments, T e is about 7 keV and E crit ഠ 100 keV, which is also the deuteron energy at which the deuterium-tritium (D-T) fusion cross section peaks. High fusion power is thus achieved at the same time as equal ion and electron heating.Several ion cyclotron resonance heating (ICRH) schemes in D-T plasmas have been included in the design of the JET system [2] which thus covers a wide frequency band, 23-57 MHz. The same schemes are being considered for the ITER reactor [3]. Three of these scenarios are minority deuterium and minority He 3 at their fundamental resonances and majority tritium at its second harmonic resonance. Recent calculations [4,5] for ITER predict that each method can produce more than 50% ion heating on the route to ignition. The present experiments have demonstrated and assessed the fundamental deuterium scheme, which has never been used previously. Also, the physics and performance of all three methods have been studied for the first time in H mode, D-T plasmas heated predominantly by ICRH. The plasmas were similar to those expected in ITER in terms of shape, safety factor ͑q͒, normalized confinement time, and the behavior of edge localized modes (ELMs), which affec...

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Neutron ionization chambers

Cited by 20 publications

References 145 publications

Determination of Resonance Parameters and their Covariances from Neutron Induced Reaction Cross Section Data

Determination of Resonance Parameters and their Covariances from Neutron Induced Reaction Cross Section Data

Results from the TARC experiment: spallation neutron phenomenology in lead and neutron-driven nuclear transmutation by adiabatic resonance crossing

D-T Fusion with Ion Cyclotron Resonance Heating in the JET Tokamak

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