Lateral movement of a laser-accelerated proton source on the target's rear surface.
The spatial dependence of proton acceleration at the rear surface of a target that is irradiated by high-contrast and ultraintense laser pulses is investigated. Lateral movement of the proton acceleration position at the rear surface is observed; this is tested by a two-pinhole measurement which results in the observation of protons with a narrow energy band. This drifting is only observed when relativistic-intensity laser pulses irradiate targets with a small preplasma at oblique incidence, as is confirmed by two-dimensional particle-in-cell simulations. This scenario of proton acceleration by the fast-moving sheath field leads to energy selection of the accelerated protons as a function of observing position.
Institute of Laser Engineering, Osaka University, Suita, Osaka, Japan. nakamura.tatsufumi@jaea.go.jp
Tatsufumi
T
Nakamura
Kunioki
K
Mima
Sargis
S
Ter-Avetisyan
Matthias
M
Schnürer
Thomas
T
Sokollik
Peter V
PV
Nickles
Wolfgang
W
Sandner