James C L Chow and Grigor N Grigorov 2006 Phys. Med. Biol. 51 N231 doi:10.1088/0031-9155/51/12/N01
James C L Chow1,2 and Grigor N Grigorov3
Show affiliationsThe peripheral dose outside the applicators in electron beams was studied using a Varian 21 EX linear accelerator. To measure the peripheral dose profiles and point doses for the applicator, a solid water phantom was used with calibrated Kodak TL films. Peak dose spot was observed in the 4 MeV beam outside the applicator. The peripheral dose peak was very small in the 6 MeV beam and was ignorable at higher energies. Using the 10 × 10 cm2 cutout and applicator, the dose peak for the 4 MeV beam was about 12 cm away from the field central beam axis (CAX) and the peripheral dose profiles did not change with depths measured at 0.2, 0.5 and 1 cm. The peripheral doses and profiles were further measured by varying the angle of obliquity, cutout and applicator size for the 4 MeV beam. The local peak dose was increased with about 3% per degree angle of obliquity, and was about 1% of the prescribed dose (angle of obliquity equals zero) at 1 cm depth in the phantom using the 10 × 10 cm2 cutout and applicator. The peak dose position was also shifted 7 mm towards the CAX when the angle of obliquity was increased from 0 to 15°.
87.53.Bn Dosimetry/exposure assessment
Issue 12 (21 June 2006)
Received 23 February 2006, in final form 17 April 2006
Published 31 May 2006
James C L Chow and Grigor N Grigorov 2006 Phys. Med. Biol. 51 N231
A. Savcheva et al 2009 ApJ 702 L32
Chanda J. Jog 2000 ApJ 542 216
Jennifer M. Lotz et al. 2004 ApJ 613 262
E D L Wickham et al 2006 Class. Quantum Grav. 23 S819
A S Alnaser et al 2006 J. Phys. B: At. Mol. Opt. Phys. 39 S485
W Fulop 1957 J. Sci. Instrum. 34 453
A Rogers 1992 J. Phys. A: Math. Gen. 25 6043
Michael Stabin 2006 Phys. Med. Biol. 51 R187
Lewis Ryder 1998 J. Phys. A: Math. Gen. 31 2465