Warning: file_get_contents(https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&id=12841788
&cmd=llinks): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests
in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 215
Neutron source strength measurements for Varian, Siemens, Elekta, and General
Electric linear accelerators
#MMPMID12841788
Followill DS
; Stovall MS
; Kry SF
; Ibbott GS
J Appl Clin Med Phys
2003[Sum]; 4
(3
): 189-94
PMID12841788
show ga
The shielding calculations for high energy (>10 MV) linear accelerators must
include the photoneutron production within the head of the accelerator.
Procedures have been described to calculate the treatment room door shielding
based on the neutron source strength (Q value) for a specific accelerator and
energy combination. Unfortunately, there is currently little data in the
literature stating the neutron source strengths for the most widely used linear
accelerators. In this study, the neutron fluence for 36 linear accelerators,
including models from Varian, Siemens, Elekta/Philips, and General Electric, was
measured using gold-foil activation. Several of the models and energy
combinations had multiple measurements. The neutron fluence measured in the
patient plane was independent of the surface area of the room, suggesting that
neutron fluence is more dependent on the direct neutron fluence from the head of
the accelerator than from room scatter. Neutron source strength, Q, was
determined from the measured neutron fluences. As expected, Q increased with
increasing photon energy. The Q values ranged from 0.02 for a 10 MV beam to
1.44(x10(12)) neutrons per photon Gy for a 25 MV beam. The most comprehensive set
of neutron source strength values, Q, for the current accelerators in clinical
use are presented for use in calculating room shielding.
free
free
free
