Laser and Particle Beams
Katarzyna Batani
Volume: 2022 Issue 2
2 Article(s)
Singh R.L., White S., Charlwood M., Keenan F.P., Hyland C., Bailie D., Audet T., Sarri G., Rose S. J., Morton J., Baird C., Spindloe C., and Riley D.

We have employed the VULCAN laser facility to generate a laser plasma X-ray source for use in photoionization experiments. A nanosecond laser pulse with an intensity of order 1015 Wcm-2 was used to irradiate thin Ag or Sn foil targets coated onto a parylene substrate, and the L-shell emission in the 3.3–4.4 keV range was recorded for both the laser-irradiated and nonirradiated sides. Both the experimental and simulation results show higher laser to X-ray conversion yields for Ag compared with Sn, with our simulations indicating yields approximately a factor of two higher than those found in the experiments. Although detailed angular data were not available experimentally, the simulations indicate that the emission is quite isotropic on the laser-irradiated side but shows close to a cosine variation on the nonirradiated side of the target as seen experimentally in the previous work.

Laser and Particle Beams
Jun. 07, 2022
  • Vol. 2022 Issue 2 3234804 (2022)
  • Jia Qinggang, Wang Wenyuan, Xu Haibo, and Lu Liang

    Multi-GeV proton radiography is an important tool for diagnosing density distribution of thick objects. The magnetic lens system called Zumbro lens is widely employed because it compensates for the image distortion induced by small angle multiple Coulomb scattering (MCS) that occurs when the charged protons passing through the object. However, radiography is still suffering from chromatic aberration induced blurring, if the momentum of transmitted proton is different from the reference value of Zumbro lens. In this paper, two methods are employed to reduce chromatic aberration. The first is based on magnetic lens optimization. In addition, a new lens system is first proposed locating the downstream of Zumbro. It is named “auxiliary” lens, which can correct the chromatic aberration for certain protons with momentum far away from the reference of Zumbro lens. Monte Carlo simulation shows that this proposed lens can decrease chromatic aberration and improve the radiography image evidently.

    Laser and Particle Beams
    Jun. 11, 2022
  • Vol. 2022 Issue 2 4353314 (2022)
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