Laser‐based microfocused x‐ray source for mammography: Feasibility study

Abstract

A laser-produced plasma (LPP) x-ray source with possible application in mammography was created by focusing a laser beam on a Mo target. A Table-Top-Terawatt (TTT) laser operating at 1 J energy per pulse was employed. A dual pulse technique was used. Maximum energy transfer (approximately 10%) from laser light to hot electrons was reached at a 150 ps delay between pulses and the conversion efficiency (hard x-ray yield/laser energy input) was approximately 2 x 10(-4). The created LPP x-ray source is characterized by a very small focal spot size (tens of microns), Gaussian brightness distribution, and a very short pulse duration (a few ps). The spectral distribution of the generated x rays was measured. Images of the focal spot, using a pinhole camera, and images of a resolution pattern and a mammographic phantom were obtained. The LPP focal spot modulation transfer function for different magnification factors was calculated. We have shown that the LPP source in conjunction with a spherically bent, high throughput, crystal monochromator in a fixed-exit Rowland circle configuration can be used to created a narrow band tunable mammography system. Tunability to a specific patient breast tissue thickness and density would allow one to significantly improve contrast and resolution (exceeding 20 lp/mm) while lowering the exposure up to 50% for thicker breasts. The prospects for the LPP x-ray source for mammographic application are discussed.

Intense High-Contrast FemtosecondK-Shell X-Ray Source from Laser-Driven Ar Clusters

“…[1][2][3][4][5]. Such hard x-ray sources have a number of interesting applications in imaging [6][7][8][9]. This kind of intense and ultrafast hard x-ray source can pose as a possible alternative to the synchrotron radiation due to its compactness, its low cost compared to big facility and its fs pulse duration, and is, therefore, of interest for practically using in majority of labs and hospitals.…”

Dependence of hard x-ray yield on laser pulse parameters in the wavelength-cubed regime

“…The photon energy of its K-line emissions is ϳ17.5 keV, which is suitable for mammography. 15 These experiments utilize a compact table-top Ti:sapphire chirped-pulse-amplified laser system. This laser produces a train of pulses with 1.1 mJ pulse energy, 22 fs pulse duration, at 400 Hz repetition rate.…”

Some applications of ultrashort laser pulses in biology and medicine

“…The greatest potential of the laser-based x-ray source seems to be for the gated-viewing reduction of scattered radiation, since even modest reductions in absorbed x-ray doses could mean substantial savings in radiation-damage-induced suffering and costs. Mammographic applications [46] are attractive besides angiographic imaging. A high-average-power source would have to be integrated with a high-efficiency 2D gated x-ray detector, which still needs to be developed.…”