Ladislav Pina

Ablation of various materials with intense XUV radiation

Ablation behavior of organic polymer (polymethylmethacrylate) and elemental solid (silicon) irradiated by single pulses of XUV radiation emitted from Z-pinch, plasma-focus, and laser-produced plasmas was investigated. The ablation characteristics measured for these plasma-based sources will be compared with those obtained for irradiation of samples with XUV radiation generated by a free-electron laser.

High-brightness laser plasma soft X-ray source using a double-stream gas puff target irradiated with the Prague Asterix Laser System (PALS)

High brightness laser plasma soft X-ray source based on a recently developed double-stream gas puff target irradiated with 0.5 ns laser pulses with energies up to 700 J from the Prague Asterix Laser System (PALS) is presented. The gas puff target was created by pulsed injection of xenon into a hollow stream of helium using an electromagnetic valve system with the double-nozzle setup. Soft X-ray emission was measured using the transmission grating spectrograph coupled to a CCD camera and the calibrated silicon photodiodes. The absolute soft X-ray production was determined to be 160 J for 540 J of laser energy, giving the soft X-ray conversion efficiency of about 30%. The source has been used in initial experiments on soft X-ray ablation of organic polymers and elemental solids.

Focusing Mirrors for Use with Microfocus X-ray Tubes

Several different types of X-ray mirrors suitable for use with a microfocus X-ray tube and intended principally for single-crystal diffractometry are discussed and compared. The construction and performance of ellipsoidal mirrors made by an electroforming method are described in detail. The intensity at the mirror focus is comparable with the flux obtained with conventional arrangements with X-ray tubes dissipating more than 100 times the power of the microfocus tube.

A High-Power Laser-Driven Source of Sub-nanosecond Soft X-Ray Pulses for Single-Shot Radiobiology Experiments

Abstract Davídková, M., Juha, L., Bittner, M., Koptyaev, S., Krása, J., Pfeifer, M., Štísová, V., Bartnik, A., Fiedorowicz, H., Mikolajczyk, J., Ryc, L., Pína, L., Horváth, M., Babánková, D., Cihelka, J. and Civiš, S. A High-Power Laser-Driven Source of Sub-nanosecond Soft X-Ray Pulses for Single-Shot Radiobiology Experiments. Radiat. Res. 168, 382–387 (2007). A large-scale, double-stream gas puff target has been illuminated by sub-kJ, near-infrared (NIR) focused laser pulses at the PALS facility (Prague Asterix Laser System) to produce high-energy pulses of soft X rays from hot, dense plasma. The double-puff arrangement ensures high gas density and conversion efficiency from NIR to X rays approaching that typical for solid targets. In addition, its major advantage over solid targets is that it is free of debris and has substantially suppressed charged-particle emission. The X-ray emission characteristics of the source were determined for a range of gases that included krypton, xenon, N2, CO and N2-CO. A demonstrated application of the xenon-based source is a single-shot damage induction to plasmid DNA. The yields of single-strand breaks (SSBs) and double-strand breaks (DSBs) were determined as a function of energy fluence adjusted by varying distance of sample from the source and thickness of aluminum filters.

Lobster-eye x-ray telescopes: recent progress

We describe and discuss the LOBSTER EYE X-ray telescope project including recent results of the development and tests of advanced telescope prototypes. They include both very small (3 × 3 mm) as well as large (300 × 300 mm) Schmidt lenses. Considerations for a space experiment on a small scientific satellite of a Nadezhda type are also discussed.

Lobster eye x-ray optics

The imaging x-ray telescopes in current use mostly have limited field of view. The alternative x-ray optics geometries achieving very large fields of view have been theoretically suggested in the 70s but have been not constructed and used so far. We review the design and basic properties of the wide-field x-ray optical system based on one- and two-dimensional lobster-eye geometry and suggest technologies for their development and construction. First results of the development of replicated x-ray reflecting cells for use in 2D x-ray optics of Angel lobster eye type are presented and discussed.

Replicated grazing incidence x-ray optics: past, present, and future

The development of x-ray optics with focus on replicated grazing incidence mirrors has a long tradition in the Czech Republic. The design of the first x-ray imaging lenses stated in late 60s and the first mirrors have been available since 1970. They were flown on 8 space probes and/or experiments so far. Recently, we participate in the design and development of innovative x-ray optics for future space missions, especially for those with very large field of view. These lenses are believed to allow the first deep monitoring of the sky sphere in x-rays. There are also numerous ground-based laboratory applications.

Investigation of soft x-ray emission in the water window for microscopy using a double-stream gas puff target irradiated with the Prague Asterix Laser System (PALS)

Measurements of soft x-ray emission from a nitrogen/helium double-stream gas puff target irradiated with the Prague Asterix Laser System (PALS) have been performed. The aim of the studies was to measure the absolute yields of soft x-ray radiation in the water window from a gas puff laser plasma source and to verify the possibilities of using of this source in x-ray imaging microscopy.

Ablation of Organic Polymers and Elemental Solids Induced by Intense XUV Radiation

The ablation efficiency of organic polymers (polymethylmethacrylate ‐ PMMA, polytetrafluoroethylene ‐ PTFE, polyethyleneterephtalate ‐ PET, and polyimide ‐ PI) and elemental solids (aluminum and silicon) by single pulses of extreme ultraviolet (XUV) radiation emitted from Z‐pinch, plasma‐focus, and laser‐produced plasmas was investigated. The ablation characteristics measured for these plasma‐based sources will be compared with those obtained for irradiation of samples with XUV radiation generated by a free‐electron laser (FEL). The Z‐pinch was driven by the S‐300 pulsed‐power machine (Kurchatov Institute, Moscow) and the plasma focus was realized in the PF‐1000 machine (Institute of Plasma Physics and Laser Microfusion, Warsaw). Higher temperature plasma than with the discharge plasmas was obtained by focusing the near‐infrared (fundamental frequency) beam from the PALS high‐power iodine laser system (Czech Academy of Sciences, Prague) on the surface of a metallic slab target or into single‐ and double‐g...

Progress in Lobster - Eye X-ray optics development

The Lobster-eye optics represents a promising way of very wide field X-ray imaging with numerous applications especially in future X-ray astronomy projects and in fast yet sensitive monitoring of X-ray sky. We report on recent developments in design and construction of wide-field optical elements of Schmidt and Angel geometry. New compact Lobster-eye modules with both geometrical arrangements have been developed and tested. They feature improved parameters such as surface quality and angular resolution. Computer ray-tracing and first experimental results obtained in visible and X-ray regions are presented.