Characterization of multiterawatt laser-solid interactions for proton acceleration

A comprehensive characterization of experimental parameters in a study of proton acceleration by short-pulse laser–solid interactions at intensities up to 10 19   W cm −2 is reported. Laser pulse and prepulse conditions were measured, with a contrast ratio of the order of 10 −6 obtained. The focused...

Full description

Saved in:
Bibliographic Details
Published in:Review of scientific instruments 2002-12, Vol.73 (12), p.4176-4184
Main Authors: McKenna, P., Ledingham, K. W. D., Spencer, I., McCany, T., Singhal, R. P., Ziener, C., Foster, P. S., Divall, E. J., Hooker, C. J., Neely, D., Langley, A. J., Clarke, R. J., Norreys, P. A., Krushelnick, K., Clark, E. L.
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A comprehensive characterization of experimental parameters in a study of proton acceleration by short-pulse laser–solid interactions at intensities up to 10 19   W cm −2 is reported. Laser pulse and prepulse conditions were measured, with a contrast ratio of the order of 10 −6 obtained. The focused laser intensity was experimentally calibrated using a time-of-flight spectrometer to resolve the stages of ionization of a target gas. By comparing the measured ion yields with predictions of an atomic tunneling ionization model a factor of 1.5 uncertainty in the focused intensity was determined. Drive mechanisms for mounting solid targets with thickness in the range of 0.2 to 125 μm have been developed for use with high-repetition rate lasers. A retro-focus imaging system has also been implemented to position the target relative to the laser focus. The techniques have been applied to study proton acceleration as a function of various laser and target parameters. Measurements of the energy distribution of protons as a function of laser intensity are presented for both mylar and Al targets. A maximum proton energy of 1.5 MeV was observed. A compilation of recent results from a number of laser systems on the conversion efficiency of laser energy to protons is discussed. By comparison, an efficiency of about 0.7% for the present study is encouraging for future tabletop-laser-based ion acceleration.
ISSN:0034-6748
1089-7623
DOI:10.1063/1.1516855