Prompt gamma radiation

Pierce, T. B., P. F. Peck, and W. M. Henry Determination of Carbon in Steels by Measurement of the Prompt Gamma-Radiation Emitted During Proton Bombardment. Nature 204, 571 (1964). 

The spectrum peaks from prompt gamma radiation are acquired only during the activation hence, peak areas do not need to be corrected for decay. 

The energy range of prompt gamma radiation extends from a few tens of keV up to 12 MeV. There are two detector types in practice that are able to detect gamma rays over this wide energy range the solid scintillation detector and the germanium semiconductor detector ... 

Prompt gamma radiation from neutron capture of detector and surroundings Cu, Cd. 

I-ll. Prompt gamma radiation due to the activation of samples situated in a neutron beam outside the shielding may pose a significant radiation and contamination hazard. 

Sodium iodide I is a radiopharmaceutical/antithyroid agent. After rapid GI absorption, iodine I is primarily distributed within extracellular fluid. It is trapped and rapidly converted to protein-bound iodine by the thyroid it is concentrated, but not protein bound, by the stomach and salivary glands. It is promptly excreted by kidneys. About 90% of the local irradiation is caused by beta radiation and 10% is caused by gamma radiation. I has a physical half-life of 8.04 days. It is indicated in the treatment of thyroid carcinoma, hyperthyroidism. 

The prompt gamma rays formed by capture reactions are of analytical interest in some cases, but the radionuclide produced ( Na) and its decay radiations are more often used in NAA. 

For short half-lives, C approaches zero and the counting increases linearly with the measurement time. This is automatically the case when prompt radiation is detected instead of decay radiation. For this reason, prompt gamma activation analysis is inherently more sensitive than delayed gamma activation analysis. 

Activation methods are based on the measurement of the radioactivity or radiation produced in samples when they are irradiated with neutrons or charged particles, such as hydrogen, deuterium, or helium ions. An overview of the most common type of neutron activation is shown in Figure 32-6. Here, a neutron is captured by the target nucleus to form an excited compound nucleus. The compound nucleus de-excites almost instantaneously by emission of one or more characteristic prompt gamma rays. In many cases a new radioactive nucleus is formed, which can undergo /3 decay to an exited product nucleus with the emission of another characteristic delayed gamma ray. 

DT-236/PDR-75. NSN 6665-01-211-4217. The AN/PDR-75 provides the capability to monitor and record the exposure of individual personnel to gamma and neutron radiation through a wrist worn device. It is a tactical dosimeter with 1 to 1000 cGy indirect reading for neutron and gamma dose measurement by separate devices. It responds to and measures prompt radiation from nuclear bursts. The PRD-75 will be used to calculate unit radiation status, for medical triage, and for unit reconstitution. Elements are encased in a tamper resistant locket, which is worn on the wrist. Dosages are cumulative and are permanently recorded. 

Prompt activation analysis (Erdtmann and Petri, 1986 Alfassi, 1990) uses the prompt radiation accompanying a nuclear reaction for determining elemental or isotopic concentrations. The variety of prompt methods is large because a sample can be irradiated with various particles - neutrons, charged particles or gamma-rays. Prompt activation analysis permits the determination of several elements - about 17 elements in environmental matrices (Germani et al., 1980) - but most analysis are used for the determination of light elements (H, He, Li, B, C, N, Si, S, Cl) as well of Cd and Gd. 

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