Beta Emission and Bremsstrahlung

PROMPT BETA SPECTROSCOPY AS A DIAGNOSTIC FOR MIX IN IGNITED NIF CAPSULES

Modern Physics Letters A ◽

10.1142/s0217732306020317 ◽

2006 ◽

Vol 21 (13) ◽

pp. 1029-1040 ◽

Cited By ~ 8

Author(s):

A. C. HAYES ◽

GERARD JUNGMAN ◽

J. C. SOLEM ◽

P. A. BRADLEY ◽

R. S. RUNDBERG

Keyword(s):

Laser Beam ◽

Beam Energy ◽

High Energy ◽

Shell Material ◽

National Ignition Facility ◽

Confinement Fusion ◽

Order Of Magnitude ◽

Beta Spectroscopy ◽

Fundamental Physical ◽

Beta Emission

The National Ignition Facility (NIF) technology is designed to drive deuterium–tritium (DT) internal confinement fusion (ICF) targets to ignition using indirect radiation from laser beam energy captured in a hohlraum. Hydrodynamical instabilities at interfaces in the ICF capsule leading to mix between the DT fuel and the ablator shell material are of fundamental physical interest and can affect the performance characteristics of the capsule. Here we describe new radiochemical diagnostics for mix processes in ICF capsules with plastic or Be (0.9% Cu ) ablator shells. Reactions of high-energy tritons with shell material produce high-energy β-emitters. We show that mix between the DT fuel and the shell material enhances high-energy prompt beta emission from these reactions by more than an order of magnitude over that expected in the absence of mix. We further show how a mix signal could be detectable in an ignition failure regime corresponding to yields greater than about 2 kJ.

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Coulomb Fragmentation of Molecules Following Beta Emission

Physical Review Letters ◽

10.1103/physrevlett.22.753 ◽

1969 ◽

Vol 22 (15) ◽

pp. 753-755 ◽

Cited By ~ 9

Author(s):

M. Berman ◽

G. B. Beard

Keyword(s):

Beta Emission

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Paschen beta emission as a tracer of outflow activity from T-Tauri stars, as compared to optical forbidden emission

Astronomy and Astrophysics ◽

10.1051/0004-6361:20034381 ◽

2004 ◽

Vol 417 (1) ◽

pp. 247-261 ◽

Cited By ~ 53

Author(s):

E. T. Whelan ◽

T. P. Ray ◽

C. J. Davis

Keyword(s):

T Tauri Stars ◽

T Tauri ◽

Beta Emission

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THERMOCOAX rhodium SPND sensitivity dispersion and validation of the sensitivity calculation model

EPJ Web of Conferences ◽

10.1051/epjconf/202022504015 ◽

2020 ◽

Vol 225 ◽

pp. 04015

Author(s):

L. Vermeeren ◽

W. Leysen ◽

L. Pichon ◽

V. Salou ◽

G. Helleux

Keyword(s):

Gamma Rays ◽

Neutron Capture ◽

Characteristic Time ◽

Thermal Neutron Flux ◽

Calculation Model ◽

Delayed Response ◽

Neutron Detectors ◽

Recorded Data ◽

Self Powered ◽

Beta Emission

This paper describes the neutron irradiation tests of 7 THERMOCOAX Self-Powered Neutron detectors (SPNDs) in the BR1 reactor at SCK•CEN. The SPNDs were fabricated according to the same specifications, but from different fabrication batches. The SPND signals were recorded during stepwise power-up of the reactor, proving the linearity of the SPND response within a wide thermal neutron flux range: from as low as 0.8·109 n/(cm2) to 2.6·1011 n/(cm2s). Intercomparison of the SPND signals shows a very small spread, confirming the repeatability of the THERMOCOAX fabrication processes. The overall neutron sensitivities of the seven SPNDs agreed within a 1% margin. The experimental data were analyzed in terms of prompt and various delayed responses. Prompt contributions to the signal are due to external gamma induced processes and to processes involving gamma rays emitted instantaneously upon neutron capture. The main contribution in a rhodium SPND is due to activation of the rhodium emitter and beta emission during decay of the activated rhodium and leads to a delayed response with a characteristic time of a few minutes. Activation and subsequent beta decay in other materials present in the SPND lead to additional minor delayed signal contributions. The partial SPND sensitivities due to all these processes were calculated using an MCNPX based model and were compared with experimental sensitivities based on the recorded data. The results were in fair agreement; for the overall SPND neutron sensitivity an agreement within a 1% margin was achieved.

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