NEUTRON AND GAMMA DOSE DISTRIBUTION BEYOND VARIOUS SECTIONS OF TOP PLUG MOCKUP NO. 2 (BERYLLIUM, SOLID IRON, BORON CARBIDE, WATER, AND IRON-WATER MIXTURE)

Technical Report · Fri Aug 01 04:00:00 EDT 1952

OSTI ID:4332970

Clifford, C E

Top plug mockup 2 was the first experimental check of the intial top plug design using B/sub 4/C in a thick layer in the high-temperature region of the plug. Thick mockup included the 20-in. B/sub 4/C slab which contained occluded water in an unknown amount due to improper storage. Since the water is very effective in removing the intermediate energy neutrons which would normally have penetrated the B/sub 4/C and would have been captured in the iron layers following it, the mockup gives an underestimate of the capture gamma source in the iron-water layers. An attempt was made to estimate the effect of the water in the 20-in. B/sub 4/C slab by eliminating water from between the iron slabs. Since the iron appears to be as effective as could be expected and no increase in the gamma dose was noted upon the elimination of 20 cm of water in the iron-water mixture, it is concluded that capture gammas in this design are not a significant fraction of the measured ganama dose. The measurement of the ganama dose was very difficult since the radiation from the source was less than the background. The neutron dose could not be measured directly with the dosimeter because of the low intensity. The thermal flux was used to estimate the fast neutron dose on the basis of a previous comparison with the dosimeter reading in a pure water shield where the neutron relaxation length was between 7 and 9 cm. Since other measurements have indicated that for neutron relaxation lengths as short as those prevalent beyond this mockup, this procedure overestimates the dose by roughly an order of magnitude; therefore, the reported dose is felt to be a conservative upper limit. (A.C.)

• Research Organization: Oak Ridge National Lab., Tenn.
• DOE Contract Number: W-7405-ENG-26
• NSA Number: NSA-12-008195
• OSTI ID: 4332970
• Report Number(s): CF-52-5-1(Pt.4)(Del.)
• Country of Publication: United States
• Language: English

Related Subjects

ATOMS
BEAMS
BERYLLIUM
BORON CARBIDES
CAPTURE
CURRENTS
DECOMPOSITION
DENSITY
DOSEMETERS
ELECTRIC ARCS
ENERGY RANGE
FAST NEUTRONS
GAMMA RADIATION
HIGH TEMPERATURE
HYDROGEN
INJECTION
ION SOURCES
IONS
IRON
KEV RANGE
LAYERS
MAGNETIC FIELDS
MAGNETIC MIRRORS
MEASURED VALUES
MIXING
MOCKUP
MOLECULES
NEUTRON BEAMS
NEUTRON FLUX
PHYSICS
PLANNING
PLASMA
PUMPS
RADIATION DOSES
RELAXATION LENGTH
SHIELDING
THERMAL NEUTRONS
THERMONUCLEAR DEVICES
VACUUM
WATER