
================================    tube_w   ===================================


 tube_w calculates the spectum of a Tungsten X-ray tube.

 It uses a routine routine to generates spectra (photons/mm**2 per keV) for 
 one mAs and the output is calibrated to the output of a constant potential 
 generator in our laboratory (a Toshiba Model 2050 x-ray generator with a 
 "Rotanode" x-ray tube with housing model DRX-573HD-S and insert model 
 DR-5735H).
 These spectra were calibrated to output (mR/mAs) values and HVL values
 that were measured down the central axis of the x-ray beam.  The output
 data are given in the manuscript:

 "An accurate method for computer- generating tunsten anode x-ray spectra from 
 30 to 140 kV",
 JM Boone and JA Seibert, Medical Physics 24(11) pp.1661-1670, 1997.

 http://dx.doi.org/10.1118/1.597953


 The program TASMIP  interfaced here has been downloaded from:
 ftp://ftp.aip.org/epaps/medical-phys/E-MPHYA-24-1661


               Description of the input parameters for TUBE_W:
               ===============================================


VOLTAGE:     anode voltage in kiloVolts (in the 30-140 interval)
VOLTAGE RIPPLE: RMS value in %
AL FILTER: Al filtration: layer thickness in mm



