Predicted flash x-ray environments using standard converter configurations
Using a sophisticated Monte Carlo model, we have obtained predictions of the forward radiation fields generated by a series of monoenergetic electron sources, with kinetic energies ranging from 0.5 to 15.0 MeV, normally incident on standard converter configurations. The tantalum converter foil thickness that maximizes the total forward-going x-ray energy ranges from 0.3 times the continuous-slowing-down-approximation electron range at 0.5 MeV to 0.6 times that range at 15.0 MeV. This result is not very sensitive to the presence or absence of typical electron absorbers or debris shields. The forward extraction efficiency exhibits a slightly superlinear dependence on source electron kinetic energy. Electron backscatter and photon absorption are shown to be the chief transport phenomena that limit x-ray extraction. Dependence of x-ray spectra on emission angle results from the complicated interplay of cross-section kinematics, slant-thickness absorption, and slant-thickness buildup. The response of common dosimetry materials to the radiation fields was also studied. The systematics of energy deposition in high-Z and low-Z dosimetry materials as a function of source energy, converter geometry, and emission angle are presented in terms of an effective absorption coefficient. The utility of this coefficient for predicting the energy deposition in one material from the measured dose in another material is demonstrated. It is shown that the converter thickness that optimizes dose is less than the thickness that optimizes the forward extraction efficiency. 11 refs., 32 figs.
- Research Organization:
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 5291181
- Report Number(s):
- SAND-83-2572; ON: DE86000824
- Country of Publication:
- United States
- Language:
- English
Similar Records
Experimental verification of bremsstrahlung production and dosimetry predictions as a function of energy and angle
Use of appropriate absorption coefficients in gamma-ray dosimetry
Related Subjects
43 PARTICLE ACCELERATORS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
X-RAY SOURCES
BEAM EXTRACTION
SPATIAL DOSE DISTRIBUTIONS
ANGULAR DISTRIBUTION
COMPUTER CALCULATIONS
MEV RANGE 01-10
MEV RANGE 10-100
MONTE CARLO METHOD
PHOTON TRANSPORT
PULSE TECHNIQUES
SCATTERING
THEORETICAL DATA
X-RAY EQUIPMENT
DATA
DISTRIBUTION
ENERGY RANGE
EQUIPMENT
INFORMATION
MEV RANGE
NEUTRAL-PARTICLE TRANSPORT
NUMERICAL DATA
RADIATION DOSE DISTRIBUTIONS
RADIATION SOURCES
RADIATION TRANSPORT
070200* - Radiation Sources
430303 - Particle Accelerators- Experimental Facilities & Equipment
654001 - Radiation & Shielding Physics- Radiation Physics
Shielding Calculations & Experiments