title: Silicon diode detectors used in radiological physics measurements. Part I: Development of an energy compensating shield.
abstract: Silicon diode detectors have the advantages of high resolution, large signal, and fast response, but lack the flat energy response of the Farmer ion chamber. A study was undertaken to develop a compensating shield for a diode which would make it suitable for use in the spectrum of energies produced by a high-energy radiation beam at depth in a phantom. The energy response of the unshielded diode was quantitated over a range of energies from 18.5 keV to 8 MeV. Shields of different thickness, density, and design were tested experimentally. A partial shield of high-Z material over a diode with miniaturized contacts produced a probe which duplicated the relative dose measurements of the Farmer chamber with less than 1% variation. Typical central axis depth-dose curves and a beam profile, measured with the chamber and the shielded and unshielded probe, are illustrated.
mesh_terms: D003037:Cobalt Radioisotopes; D005720:Gamma Rays; D011829:Radiation Dosage; D011874:Radiometry / Q000295:instrumentation*; D012666:Semiconductors; D012825:Silicon; D014965:X-Rays
chemical_list: D003037:Cobalt Radioisotopes; D012825:Silicon