Measured Flux vs. Photon Energy Bremsstrahlung X-Ray Spectra

["David W. Lee" <lee_david_w@lanl.gov>]

GROUP:

	As you are aware qualitative graphical depictions of x-ray flux vs. photon
energy spectrum can be readily found in many references such as:

	Profio, Radiation Shielding and Dosimetry, 1979, page 32.
	Curry et al., Christensen's Physics of Diagnostic Radiology, 4th Ed., p. 33.
	Bushong, Radiologic Science for Technologists, 6th Ed., p. 132.

	The "rule of thumb" is that the average energy of the x-ray photons will
be approximately 1/3 of the maximum electron acceleration energy.  Thus,
electrons accelerated into a tungsten x-ray production target at an x-ray
tube acceleration voltage of 150 kVp will give rise to a polyenergetic
bremsstrahlung x-ray spectrum; the majority of the photons comprising the
spectrum will have individual energies in and around about 50 keV.

	Currently, we are using the Monte Carlo code (MCNP) to calculate the
bremsstrahlung spectrum from various x-ray units and LINACS. For comparison
purposes, we are searching the literature for examples of MEASURED spectra
with which to benchmark our MCNP calculations.  Much information has been
found in the diagnostic x-ray energy range, and much measured data appears
to exist for x-ray photon energies up through 140 kVp, which encompasses
spectra from CT scanners.  Some spectra has been found up to 300 KeV.  For
example:

	R.G. Waggener, L.B. Levy, L.F. Rogers, and P.Zanca. "Measured x-ray
spectra from 25 to 110 kVp for a typical diagnostic unit." Radiology
105:169-175 (1972).

	E.Storm, H.Israel, and D.Lier. "Bremsstrahlung Emission Measurement from
Thick Tungsten Targets in Energy Range 12 to 300 kV." LA-4624, Los Alamos,
NM (1970).

	T.R. Fewell, R.E.Shuping, and K.R. Hawkins. "Handbook of Computed
Tomography X-Ray Spectra." HHS(FDA) 81-8162 (1981).

	We are interested, however, in a higher energy range (300 KeV - 10 MeV).
Does anyone know of publications or data of quantitative flux vs. x-ray
photon energy in this higher energy range?

Best regards,  David


David W. Lee
Los Alamos National Laboratory
Radiation Protection Services Group (ESH-12)
PO Box 1663, MS K483
Los Alamos, NM  87545
PH:   (505) 667-8085
FAX:  (505) 667-9726
lee_david_w@lanl.gov