ENERGY AND ANGULAR DISTRIBUTION OF GAMMA RAYS, BREMSSTRAHLUNG AND ANNIHILATION RADIATION IN A LEAD CYLINDER
A Monte Carlo Program for the IBM 704 was developed for calculating the energy spectrum of gamma rays reaching a detector at amy point inside a finite openended cylindrical shield. The shield may comprise up to ten coaxial regions representing different materials. The energy spectrum and angular distribution of the gamma rays incident upon the outside of the cylhender are assumed to be known. In the mathmatical model, the following phenomena are considered: Compton scattering and the bremsstrahlung associated with the Compton electron, photoelectric absorption and the associated bremsstrahlung, and pair production including the associated annihilation radiation and bremasstrahlung. The Klein- Nishina equation is simulated by a fourth-degree polynomial for each energy group up to a maximum of 59. Results were obtained from twenty-four 500-history calculations. Data were obtained for 1, 5, and 10 Mev gamma rays incident on the outside surface of a 6.35cm thick lead cylinder. Data were obtained for all three energies at angles of 0, 30, and 60 deg relative to the surface normal. Angles were measured in the plane of the cylindrical axis and the surface normal. Nine calculations were made for gamma rays, bremsstrahlung, and annihilation radiations followed for the entire shleld, and repeated for gamma rays only. Data showing the energy distribution and angular distribution are plotted for gamma rays only and gamma rays plus bremsstrahlung and annihilation radiation. A calculation was made at 5 and 1O Mev for gamma rays and annihilation radiation followed through the entire shield, and bremsstrahlung followed through the last 1, 2, and 3 millimeters of shielding. The data indicate that bremsstrahlung may be neglected at 1 Mev. At 5 and 10 Mev the presence of bremsstrahlung and annihilation radiation are significant if a large quantity of 5- or 10-Mev gamma rays are incident on the surface of the shield. (auth)
- Research Organization:
- Martin Co., Baltimore
- NSA Number:
- NSA-13-004794
- OSTI ID:
- 4281201
- Report Number(s):
- ER-10485
- Resource Relation:
- Other Information: Orig. Receipt Date: 31-DEC-59
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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Related Subjects
ABSORPTION
ANGULAR DISTRIBUTION
ANNIHILATION
BREMSSTRAHLUNG
COMPTON EFFECT
COMPUTERS
CYLINDERS
ELECTRONS
ENERGY
ENERGY RANGE
EQUATIONS
GAMMA RADIATION
IBM 704
KLEIN-NISHINA FORMULA
LEAD
MONTE CARLO METHOD
NUMERICALS
PAIR PRODUCTION
PHOTOELECTRIC EFFECT
POLYNOMIALS
PROGRAMMING
RADIATION DETECTORS
SCATTERING
SHIELDING
SPECTRA