Indirect neutron absorptiometry

The utility of single-photon absorptiometry and dual-energy x-ray absorptiometry.

T w o decades ago researchers at the University of Wisconsin showed that 125I photon absorptiometry could be used to measure bone mineral in the forearm easily and accurately with little radiation exposure (1). Surrounding the arm with water or other soft tissue-equivalent material of constant thickness provided uniform extra-skeletal attenuation; the incremental attenuation by bones was linear...

Transistor-amplifier units for absorptiometry.

Surrogate ratio methodology for the indirect determination of neutron capture cross sections

The relative γ -decay probabilities of the 162Dy to 161Dy and 162Dy to 164Dy residual nuclei, produced using light-ion-induced direct reactions, were measured as a function of excitation energy using the CACTUS array at the Oslo Cyclotron Laboratory. The external surrogate ratio method (SRM) was used to convert these relative γ -decay probabilities into the 161Dy(n,γ ) cross section in an equiv...

A Novel Neutron Dosimeter

Background: Neutron contamination in our environment can cause harmful biological effects on human body. Therefore, many efforts have been made to construct a neutron dosimeter to estimate the received dose. Objective: To design a simple neutron dosimeter. Methods: The primary dosimeter had 3He as a spherical thermal neutron detector encircled by paraffin 10 cm in radius. Then, the paraffin sph...

Bone mineral measurement of phalanges: comparison of radiographic absorptiometry and area dual X-ray absorptiometry.

With a standard, image-intensifier-based, digital radiographic system, high-spatial-resolution images of the hand were acquired for analysis of phalangeal bone mineral density with dual x-ray absorptiometry (DXA). Results with phalangeal DXA had precision of plus or minus 0.67% and accuracy of 4.1% and correlated well with those with radiographic absorptiometry. This phalangeal DXA technique is...