| 1. |
- Albert, F, et al.
(författare)
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Laser produced X-ray source in the 10-60 keV range at 1 kHz. Modified irradiation schemes in order to reach medical imaging quality
- 2001
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Ingår i: Journal de Physique IV. - : EDP Sciences. - 1155-4339. ; 11:PR2, s. 429-432
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Tidskriftsartikel (refereegranskat)abstract
- By tightly focusing ultra-short pulses from a Ti:sapphire terawatt laser onto a high-Z metallic target, hard x-ray pulses of short duration are produced. In most of our previous work concerning x-rays, a 150 mJ laser pulse with a 110 A duration has been used. Using mostly tin and tantalum targets, hard x-rays in the 10-60 keV range have been produced and used in differential absorption imaging around the K-alpha absorption edge of a contrast agent and also in imaging employing gated viewing for suppression of scattered radiation. In order to increase the x-ray yield (shortening the acquisition time) an increase in the laser repetition rate is desirable while still staying in the K-alpha energy regime. We have used a I kHz repetition-rate laser delivering 35 fs pulses in order to work towards these goals. We have clear evidence of hard x-ray generation above 30 keV, even for low laser pulse energies. We also studied the effect of a fs prepulse. The medical imaging capability of the source was explored. The use of a prepulse has been optimized in order to improve the image quality as well as the overall x-ray generation yield.
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| 2. |
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| 3. |
- Svanberg, Sune, et al.
(författare)
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Generation, characterization, and medical utilization of laser-produced emission continua
- 2000
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Ingår i: Laser and Particle Beams. - 0263-0346. ; 18:3, s. 563-570
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Tidskriftsartikel (refereegranskat)abstract
- Intense continua of electromagnetic radiation of very brief duration are formed in the interaction of focused ultra-short terawatt laser pulses with matter. Two different kinds of experiments, which have been performed utilizing the Lund 10 Hz titanium-doped sapphire terawatt laser system are being described, where visible radiation and X-rays, respectively, have been generated. Focusing into water leads to the generation of a light continuum through self-phase modulation. The propagation of the light through tissue was studied addressing questions related to optical mammography and specific chromophore absorption. When terawatt laser pulses are focused onto a solid target with high nuclear charge Z, intense X-ray radiation of few ps duration and with energies exceeding hundreds of keV is emitted. Biomedical applications of this radiation are described, including differential absorption and gated-viewing imaging.
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