Abstract We detail the design of a variable energy, x-ray fluorescence source using low activity (1.8×10 6 dpm) 99 Tc β that irradiates thin foils. By rotating among foils Ti, Zn, Nb, Ag, and Au, device produces x rays between 4 70 keV at rate near 1 Hz. When is placed in storage position, external radiation non-detectable. The shielding rotation mechanism permits use vacuum liquid nitrogen tem...

Objective: The use of miniature X-ray source in electronic brachytherapy is on the rise so there is an urgent need to acquire more knowledge on X-ray spectrum production and distribution by a dose. The aim of this research was to investigate the influence of target thickness and geometry at the source of miniature X-ray tube on tube output.Method: Five sources were simulated based on problems e...

We have obtained snapshot images of a transient X-ray source in M31 from Chandra ACIS-I and the Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS). The Chandra position of the X-ray nova was R.A.=00:42:56.038 ±0.08, Dec.=+41:12:18.50 ±0.07. The transient was active for at least 6 months. Previous observations set an upper limit before the X-ray outburst, demonstrating variability by...

The first coded-aperture images of the Galactic center region at energies above 30 keV have revealed two strong y-ray sources. One source has been identified with the X-ray source 1E 1740.7-2942, located 0~8 away from the nucleus. If this source is at the distance of the Galactic center, it is one of the most luminous objects in the galaxy at energies from 35 to 200 keV. The second source is co...

zns  nanoparticles  were  synthesized  via  a  simple  surfactant  free microwave  route.  in  this  synthesis, thioacetamide  was  used  as sulfur  source.  the effects  of different  parameters  such  as  type of zinc precursor,  time  and  power  of  irradiation  on  the  morphology and  particle  size  of  the  products  have been  investigated.  the nanostructures  were  characterized  by ...