Search NASA⌕ Search

SEARCH · Search NASA

Results for “GAMMA RADIATION”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 289 records · Page 16
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Mechanisms for production of the diffuse gamma-ray continuum radiation

Basic mechanisms involved in the production of cosmic gamma radiation are outlined. They include Compton interactions with low energy protons, bremsstrahlung interactions, cosmic ray induced neutral pion production, and matter-antimatter annihilation. Detailed data are given on diffuse continuum radiation. Comparative data results are given in tables and graphs.

Stecker, F. W.↗
DOE OSTI2020

Radiation-Induced Catalysis of Chemical Reactions

Nuclear energy is a process which achieves zero-carbon energy and heat generation that can provide a consistent electricity load to supply the grid when renewables are not available. However, on a cost per kilowatt-hour comparison, nuclear energy is more expensive than many of the renewable energy generation technologies such as wind and solar. In order to increase the economic viability of next generation nuclear reactors for energy production, generation of a secondary product such as a chemical feedstock would increase the economic viability of nuclear energy, particularly for new installations of next-generation nuclear reactors for power production. Currently, commercial nuclear reactors are primarily used for their heat to generate steam for electricity production. There is a large amount of unused energy in the form of photon and neutron radiation that could be exploited to drive chemical processes to produce feedstock materials as a secondary product of a nuclear plant. Chemical processing with radiation is not a new concept. In fact, gamma radiation is an excellent source of high energy photons to drive photochemical reactions. Dow chemical produced commercial quantities of ethyl bromide using gamma irradiation from a 60 Co source in the 1960s and 1970s because it was the most cost-effective means of production to meet the demand.5, 6 Due to the potential economic advantages, there is a new emphasis on studying feedstock production which can be enhanced by excess gamma and neutron radiation, particularly if the reaction could be monitored in real-time which is advantageous for process optimization. A model system of lignocellulose degradation under γ- radiation was chosen for this study while following the degradation products with Raman spectroscopy in real-time.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2021

Gamma Irradiation Facility

Gamma irradiation is a process that uses Cobalt60 radionuclide produced artificially in nuclear reactors to irradiate a variety of items using gamma radiation. A key characteristic of gamma irradiation is its high penetration capability and the fact that it can modify physical, chemical, and biological properties of the irradiated materials.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
NASA NTRS1983

Diffuse galactic emission of high energy gamma rays

A study of the gamma-radiation produced by the interaction of cosmic rays with the interstellar matter and photons is extended, based on recent COS-B satellite results and background estimates (1982) and evaluations of the 21-cm radiation in the Galaxy. Gamma-ray intensities predicted over the latitude range of -10 to 10 degrees for energy ranges 70-150, 150-300, and 300-5000 MeV agree well with the COS-B longitude distributions. The agreement suggests that the radial distribution of the emission, calculated from the model, is also approximately correct. The energy spectrum is calculated using COS-B and SAS-2 data. Finally, it is noted that contribution by the arms on the far side of the Galaxy for small galactic latitudes (between -0.4 and +0.4 degrees) makes it possible to identify very large far-side molecular clouds.

Kniffen, D. A.↗
NASA NTRS1990

Production of monodisperse, polymeric microspheres

Very small, individual polymeric microspheres with very precise size and a wide variation in monomer type and properties are produced by deploying a precisely formed liquid monomer droplet, suitably an acrylic compound such as hydroxyethyl methacrylate into a containerless environment. The droplet which assumes a spheroid shape is subjected to polymerizing radiation such as ultraviolet or gamma radiation as it travels through the environment. Polymeric microspheres having precise diameters varying no more than plus or minus 5 percent from an average size are recovered. Many types of fillers including magnetic fillers may be dispersed in the liquid droplet.

Rembaum, Alan↗
DOE OSTI2023

Extreme γ –Ray Radiation Tolerance of Spectrometer–Grade CsPbBr 3 Perovskite Detectors

The perovskite compound CsPbBr 3 has recently been discovered as a promising room-temperature semiconductor radiation detector, offering an inexpensive and easy-to-manufacture alternative to the current benchmark material Cd 1–x Zn x Te (CZT). The performance of CsPbBr 3 sensors is evaluated under harsh conditions, such as high radiation doses often found in industrial settings and extreme radiation in space. Results show minimal degradation in detector performance after exposure to 1 Mrad of Co-60 gamma radiation, with no significant change to energy resolution or hole mobility and lifetime. Additionally, many of the devices are still functional after being exposed to a 10 Mrad dose over 3 days, and those that do not survive can still be refabricated into working detectors. Notably, these results suggest that the failure mode in these devices is likely related to the interface between the electrode and material and their reaction, or the electrode itself and not the material itself. Overall, the study suggests that CsPbBr 3 has high potential as a reliable and efficient radiation detector in various applications, including those involving extreme fluxes and energies of gamma-ray radiation.

36 MATERIALS SCIENCE↗
DOE OSTI2020

A Brief Introduction to Gamma and Neutron Radiation [Slides]

Objectives: Describe gamma rays in plain English; Give 3 reasons we measure gamma rays; Describe shielding effect vs gamma energy; List 4 components of the natural background; Detail the main reason we care about neutrons; and List three good neutron moderators.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗