Shielding calculations

["Scott Richards" <sr996@poppa.fab.albany.edu>]

I have been asked to recommend the shielding needed for a 18kW 
rotating anode high brilliance x-ray generator with two shutters. Copper target 
(k-alpha): 8keV. The unit will be used for diffraction investigations 
of materials.  Standard scattering geometry and crystal/slit 
monochromatization/collimation optics will be used. The detector 
consists of a positionally sensitive ionization chamber. Unit will be 
aligned at kVp = 20, mA = 10, and run at kVp=50, mA=300. Frequency of 
operation will be, on the average, 60 to 120 hrs/wk.

The x-ray beam from the generator will be monchromated to 8keV using 
monochromator crystal to eliminate white Bremsstrahlung radiation. In 
addition the beam will be collimated to a beam size of 1.5mm x 0.2 mm 
with an angular divergian <= 1 mradian.

The only information on radition levels for this device is the 
general area around it is about 2 mr/hr. The professor wants his 
technicians to be able to observe the experiment(24 hours a day)  
through several windows that will be installed in the wall separating 
the source from the main room.

Now the question: Is there any literature available with information 
that can be used to calculate the shielding needed for this type of a 
source? I have all kinds of information for mammo units and 
diagnostic x-ray machines but nothing really specialized for this 
situation.

Thanks in advance for any help. 
Scott Richards, RRPT
Radiation Safety Officer
University at Albany, SUNY
1400 Washington Ave., Chemistry B-73
Albany, NY  12222
518-442-3497
Fax: 518-442-3783
SR996@poppa.fab.albany.edu