Description:
<jats:p>Using Monte Carlo methods, neutron dosimetry for <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/mp8472-math-0002.png" xlink:title="urn:x-wiley:00942405:media:mp8472:mp8472-math-0002" /> Applicator Tube (AT) type medical sources available from Oak Ridge National Laboratory (ORNL) has for the first time been determined in terms of TG‐43 formalism. This approach, as compared to previous “along‐away” formalisms, demonstrates the relative angular independence of dose rate data, when the geometry factor has been removed. As the ORNL‐made <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/mp8472-math-0003.png" xlink:title="urn:x-wiley:00942405:media:mp8472:mp8472-math-0003" /> AT type sources are considerably physically larger than most clinical sources used today, the radial dose function increases for radii less than 3.0 mm due to breakdown of the line source model. A comparison of the <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/mp8472-math-0004.png" xlink:title="urn:x-wiley:00942405:media:mp8472:mp8472-math-0004" /> neutron radial dose function with those for other medical sources revealed similarities with that from <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/mp8472-math-0005.png" xlink:title="urn:x-wiley:00942405:media:mp8472:mp8472-math-0005" /> Differences with respect to previous <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/mp8472-math-0006.png" xlink:title="urn:x-wiley:00942405:media:mp8472:mp8472-math-0006" /> AT source neutron dosimetry data generally increased at increasing distances. This was attributed to differences in the various <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/mp8472-math-0007.png" xlink:title="urn:x-wiley:00942405:media:mp8472:mp8472-math-0007" /> AT source models and phantom compositions. The current status of <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/mp8472-math-0008.png" xlink:title="urn:x-wiley:00942405:media:mp8472:mp8472-math-0008" /> medical source fabrication and calibration procedures at ORNL is presented.</jats:p>