Full text loading...
Zero-shift thimble ionization chamber
Polarity ratio as a function of depth for the standard A1SL chamber (i.e., without the additional sleeve) compared to a selection of other chambers previously used in EPOM investigations. The polarity ratio for PTW Roos chamber was not measured for this beam, but measurements in a range of other beams at the NRC indicate that the polarity responses for the NACP and Roos chambers are basically identical.
Experimental depth-dose curves for the PTW Roos parallel-plate chamber and for the A1SL chamber showing the effect of different A1SL thimble wall thicknesses on the EPOM: Standard 1.16 mm thickness, with an additional 0.47 mm cap, and with a thicker 2.3 mm cap. The latter is in fact the protective C-552 cap supplied with the Exradin A16 chamber. Splines are fitted to the experimental data points to guide the eye, and statistical uncertainties are barely visible because they are typically smaller than the symbol size.
Article metrics loading...