Hot Electron and Pair Production from the Texas Petawatt Laser Irradiating Thick Gold Targets

TL;DR

This study investigates hot electron generation and pair production when the Texas Petawatt Laser irradiates thick gold targets, revealing unique electron spectra and no detectable positron production at high energies.

Contribution

First detailed measurement of relativistic hot electron spectra from the Texas Petawatt Laser on thick gold targets, highlighting spectral differences from other PW laser experiments.

Findings

Hot electron spectra show a peak around 10-20 MeV.

No direct evidence of positron production above background.

Spectral shape differs from other petawatt laser experiments.

Abstract

We present data for relativistic hot electron production by the Texas Petawatt Laser irradiating solid Au targets with thickness between 1 and 4 mm. The experiment was performed at the short focus target chamber TC1 in July 2011, with laser energies around 50 J. We measured hot electron spectra out to 50 MeV which show a narrow peak around 10 - 20 MeV plus high energy exponential tail. The hot electron spectral shape differs from those reported for other PW lasers. We did not observe direct evidence of positron production above background.