An investigation of the possible application of a bidimensional MWPC to x-ray absorptiometry

The advantages and disadvantages of using a xenon filled MWPC X-ray detector with a 153Gd X-ray source are examined relative to the standard scanning method using a NaI(Tl) crystal. The questions of statistical precision, spatial resolution and energy resolution are examined experimentally and theoretically. While the position sensitivity of the device offers assistance with the difficult problem of repositioning, its poor energy resolution leads to rapid saturation of the measured absorption. It is suggested that this problem can be solved by the use of filters and/or collimation on the MWPC. Given the solution of this problem it appears that the technique can yield an accuracy in the 1% region for bone mineral measurements. (author)