Effects of laser prepulse on proton generation: active manipulation of the distribution of laser accelerated proton beams

Journal Article · Tue Jun 24 00:00:00 EDT 2008 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2958208· OSTI ID:21148863

Batani, D; Redaelli, R; Dezulian, R ^[1]; Lundh, O; Lindau, F; Persson, A; Osvay, K; Wahlstroem, C -G ^[2]; Carroll, D C; McKenna, P ^[3]; Bandyopadhyay, S; Pepler, D; Neely, D ^[4]; Kar, S; Simpson, P T; Markey, K; Zepf, M ^[5]; Xu, M H; Li, Y T ^[6]

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1. Dipartimento di Fisica G.Occhialini, Universita di Milano Bicocca, Milan (Italy)
2. Department of Physics, Lund University, P.O. Box 118, S-22100 Lund (Sweden)
3. SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom)
4. CLF, Rutherford Appleton Laboratory, Didcot OX11 0QX (United Kingdom)
5. School of Mathematics and Physics, Queen's University Belfast, Belfast (United Kingdom)
6. Beijing National Laboratory for Condensed Matter Physics, Beijing (China)

Laser pre-pulse is a major issue in experiments on laser-generation of protons, often limiting the performances of laser sources. In this paper, we show how we can actively use a low intensity prepulse (<10{sup 13} W/cm{sup 2}, ns duration) to manipulate the proton beam direction or spatial energy distribution. The prepulse is focused onto the front surface of a thin foil before the arrival of the high intensity pulse ({approx_equal}10{sup 19} W/cm{sup 2}, ps duration). Under oblique high-intensity irradiation and for low prepulse intensities, the proton beam is directed away from the target normal. Deviation is towards the laser forward direction, with an angle that increases with the level and duration of the ASE pedestal. Also, for a given laser pulse, beam deviation increases with proton energy. The observations are discussed in terms of Target Normal Sheath Acceleration, in combination with a laser-controllable shock wave locally deforming the target surface. Results obtained with an annular intensity distribution of the prepulse show smooth proton beams with a sharp circular boundary at all energies. Potential mechanisms to explain the observations are discussed.

• OSTI ID: 21148863
• Journal Information: AIP Conference Proceedings, Vol. 1024, Issue 1; Conference: 1. international symposium on laser-driven relativistic plasmas applied for science, industry and medicine, Kyoto (Japan), 17-20 Sep 2007; Other Information: DOI: 10.1063/1.2958208; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
ABLATION
ACCELERATION
BEAM PRODUCTION
BEAM-PLASMA SYSTEMS
COLLECTIVE ACCELERATORS
ENERGY SPECTRA
FOILS
IRRADIATION
LASER RADIATION
LASERS
PLASMA PRODUCTION
PLASMA SHEATH
PLASMA WAVES
PROTON BEAMS
PROTONS
PULSES
SHOCK WAVES