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Silicon diode detectors used in radiological physics measurements. Part I: Development of an energy compensating shield
Author(s) -
Gager L. David,
Wright Ann E.,
Almond Peter R.
Publication year - 1977
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.594348
Subject(s) - shielded cable , diode , ionization chamber , shields , optics , detector , shield , imaging phantom , materials science , range (aeronautics) , electromagnetic shielding , beam (structure) , physics , silicon , pin diode , optoelectronics , electrical engineering , ion , engineering , petrology , quantum mechanics , geology , composite material , ionization
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 thicknesses, 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.