Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Energetic electron and ion generation from interactions of intense laser pulses with laser machined conical targets
AU - Matsuoka, T.
AU - Reed, S.
AU - McGuffey, C.
AU - Bulanov, S. S.
AU - Dollar, F.
AU - Willingale, L.
AU - Chvykov, V.
AU - Kalinchenko, G.
AU - Brantov, A.
AU - Bychenkov, V. Yu.
AU - Rousseau, P.
AU - Yanovsky, V.
AU - Litzenberg, D. W.
AU - Krushelnick, K.
AU - Maksimchuk, A.
PY - 2010/5
Y1 - 2010/5
N2 - The generation of energetic electron and proton beams was studied from the interaction of high intensity laser pulses with pre-drilled conical targets. These conical targets are laser machined onto flat targets using 7-180 mu J pulses whose axis of propagation is identical to that of the main high intensity pulse. This method significantly relaxes requirements for alignment of conical targets in systematic experimental investigations and also reduces the cost of target fabrication. These experiments showed that conical targets increase the electron beam charge by up to 44 +/- 18% compared with flat targets. We also found greater electron beam divergence for conical targets than for flat targets, which was due to escaping electrons from the surface of the cone wall into the surrounding solid target region. In addition, the experiments showed similar maximum proton energies for both targets since the larger electron beam divergence balances the increase in electron beam charge for conical targets. 2D particle in cell simulations were consistent with the experimental results. Simulations for conical target without preplasma showed higher energy gain for heavy ions due to 'directed coulomb explosion'. This may be useful for medical applications or for ion beam fast ignition fusion.
AB - The generation of energetic electron and proton beams was studied from the interaction of high intensity laser pulses with pre-drilled conical targets. These conical targets are laser machined onto flat targets using 7-180 mu J pulses whose axis of propagation is identical to that of the main high intensity pulse. This method significantly relaxes requirements for alignment of conical targets in systematic experimental investigations and also reduces the cost of target fabrication. These experiments showed that conical targets increase the electron beam charge by up to 44 +/- 18% compared with flat targets. We also found greater electron beam divergence for conical targets than for flat targets, which was due to escaping electrons from the surface of the cone wall into the surrounding solid target region. In addition, the experiments showed similar maximum proton energies for both targets since the larger electron beam divergence balances the increase in electron beam charge for conical targets. 2D particle in cell simulations were consistent with the experimental results. Simulations for conical target without preplasma showed higher energy gain for heavy ions due to 'directed coulomb explosion'. This may be useful for medical applications or for ion beam fast ignition fusion.
KW - PLASMA
KW - ULTRAINTENSE
KW - ULTRASHORT
KW - ABSORPTION
KW - DENSITY
KW - LIGHT
U2 - 10.1088/0029-5515/50/5/055006
DO - 10.1088/0029-5515/50/5/055006
M3 - Journal article
VL - 50
JO - Nuclear Fusion
JF - Nuclear Fusion
SN - 0029-5515
IS - 5
M1 - 055006
ER -