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Properties of the 18‐MV photon beam from a dual energy linear accelerator
Author(s) -
Johnson Donald A.,
Ikoro Nnaemeka C.,
Chang ChengHui,
Scarbrough Edward C.,
Antich Peter P.
Publication year - 1987
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 - 10.1118/1.596118
Subject(s) - beam (structure) , linear particle accelerator , imaging phantom , photon , inverse square law , range (aeronautics) , physics , optics , dosimetry , inverse , photon energy , atomic physics , computational physics , nuclear medicine , materials science , mathematics , medicine , geometry , classical mechanics , gravitation , composite material
The beam characteristics of the 18‐MV photon beam of a Varian Clinac ® 1800 are presented. The clinically relevant parameters of central axis depth dose, tissue‐phantom ratios, peak‐scatter factors, and relative output factors are discussed and compared to 18‐MV beam data previously reported. The nominal beam energy was found to be 18.3±0.8 MV on the central axis. The beam symmetry and uniformity meet the manufacturer's specifications. The inverse‐square law is applicable within 1.4% over the clinically useful range of distances and field sizes. An empirical fit equation for the central axis depth dose is presented.