Laser-based intense hard x-ray source for mammography

Abstract

Characteristic Kα emissions from Mo, Ag and La targets irradiated by 60 fs, 600 mJ, 10 Hz Ti: Sapphire laser pulse at 10¹⁷ W/cm² - 10¹⁹ W/cm² can be potentially used in x-ray mammography. We have investigated x-ray spectra created by this novel x-ray source in this context. All the obtained spectra exhibited a dominating narrow emission lines with only a small portion of x-ray emission in Bremsstrahlung. Such spectra might be very usful in mammography and might improve contrast and dose utilizaion, as compared to a conventional mammographic x-ray tube. The effective focal spot size was of the order of 50 μm, i.e. significantly smaller than in conventional mammography. In contradiction to conventional mammography the effective x-ray focal spot size and the effective dose remained constant across the field of view. Kα conversion efficiency, from laser light to x-rays, was optimized and values as high as 2 x 10^-5 have been obtained.