Target charging effects on proton acceleration during high-intensity short-pulse laser-solid interactions

Applied Physics Letters 84:15 (2004) 2766-2768

Authors:

FN Beg, MS Wei, AE Dangor, A Gopal, M Tatarakis, K Krushelnick, P Gibbon, EL Clark, RG Evans, KL Lancaster, PA Norreys, KWD Ledingham, P McKenna, M Zepf

Abstract:

The observations of proton emission from wire targets, performed at the Rutherford Appleton Laboratory were reported. The experiments were carried out by using the Chirped Pulsed Amplification beam line of VULCAN laser facility. It was observed that the presence of objects in the vicinity of the interaction had an effect on the angular emission pattern of protons from the primary targets. The results show that the objects in close proximity of the main target can become sheath formation on the secondary object.

High-intensity-laser-driven Z pinches

Physical Review Letters 92:9 (2004)

Authors:

FN Beg, EL Clark, MS Wei, AE Dangor, RG Evans, A Gopal, KL Lancaster, KWD Ledingham, P McKenna, PA Norreys, M Tatarakis, M Zepf, K Krushelnick

Abstract:

The use of ultrahigh intensity laser pulses (I>5×1019 W cm-2) to irradiate thin wire targets was analyzed. The current was produced by the escape of fast electrons from the target, which resulted in the well-localised optical emission from the additional wire . The MHD instabilities in the pinching plasmas along with field emission of electrons from nearby objects were also observed. The X-ray power levels can be enchanced from laser driven Z pinches using wire array and X-pinch configurations, the coherent optical transition radiation from adjacent objects was also observed.

Relativistic allowed and forbidden transition probabilities for fluorine-like Fe XVIII*

Astronomy & Astrophysics EDP Sciences 416:1 (2004) 383-389

Authors:

V Jonauskas, FP Keenan, ME Foord, RF Heeter, SJ Rose, PAM van Hoof, GJ Ferland, KM Aggarwal, R Kisielius, PH Norrington

Set the controls for the heart of the Sun

Contemporary Physics Taylor & Francis 45:2 (2004) 109-121

Nuclear reactions in copper induced by protons from a petawatt laser-foil interaction

Applied Physics Letters 84:5 (2004) 675-677

Authors:

JM Yang, P McKenna, KWD Ledingham, T McCanny, S Shimizu, L Robson, RJ Clarke, D Neely, PA Norreys, MS Wei, K Krushelnick, P Nilson, SPD Mangles, RP Singhal

Abstract:

A range of laser-driven proton-induced reactions in copper from a petawatt laser-solid interaction were investigated. The experiment was carried out on petawatt arm of VULCAN Nd:Glass laser at the Rutherford Appleton Laboratory, U.K. where Cu foils were exposed to the proton beams from the laser-irradiated target which induced nuclear reactions. This technique used a very thin layer of copper which was inserted into the proton beam which had a smaller impact on the proton beam and was optimized according to the energies and intensities of the protons. The results show that the energy spectrum of the accelerated protons was in the range of 10-40 MeV.