Study of Proton stopping power in strongly coupled plasmas for Fast Ignition research.

2014 Fiscal Year Research-status Report

• Project/Area Number: 26820396
• Research Institution: Osaka University
• Principal Investigator: MORACE Alessio 大阪大学, レーザーエネルギー学研究センタ, 助教 (70724326)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: Fast Ignitor / Proton acceleration / ion stopping power

Outline of Annual Research Achievements

The results of the work so far were highly satisfactory.
In this first year we could assess almost all the preliminary issues related to the proposes experiment. In particular the target design has been modified and tested for radiation protection of the 10 micron Al foil used as proton beam generator from the radiation emitted by the implosion beams. The radiation protection has been assessed by adding a thin 5 micron thick Au layer between the cylindrical target body and the Al foil. Implosion of the cylindrical target was successfully tested using 6 GXII beams operating at 2 omega frequency (527 nm), 300 micron spot size and 300 J of energy.
Finally a test proton radiography of the cylindrical target was successfully performed. The protons were generated by focusing the LFEX pulse, with 1.4 kJ of energy, on the Al foil. A peak proton energy of 25 MeV was observed, this energy is more than sufficient to properly radiograph the cylindrical target, unimploded as well as imploded. The proton beam was recorded on a stack of radio-chromic films which analysis clearly shows the radiographed cross-section of the cylinder. The full scale experiment as well as an alternative target design will be tested in the next fiscal year.

Current Status of Research Progress

1: Research has progressed more than it was originally planned.

Reason

The initial plan was to create an experimental baseline for the ion stopping power experiment. This task was fully completed. Both implosion and ion source have been characterised and all the diagnostics worked perfectly. The target design has been improved in order to optimise the proton source and protect the proton generation foil from the ablation plasma and x-rays. The implosion of the cylindrical target has been demonstrated and the proton spectrum has been successfully recorded with proton energies exceeding 20 MeV. Moreover, a first test shot with proton generation and un-imploded cylinder has been successfully performed and the 2D cross sectional radiography of the cylinder has been obtained on radio-chromic films. The international team gathered at ILE to conduct together the measurements.
This preliminary work allowed us to have confidence about the success of the experiments for the next fiscal year.

Strategy for Future Research Activity

The project for FY2015 will be conducted as follows. A full scale experiment of the imploded cylinder plus proton source will be performed, using the data and knowledge developed in this FY2014 preparatory year. Multiple shots will be performed at different time delays between the imploding GXII pulses and the LFEX pulse for proton generation, in order to study the proton stopping power in different plasma conditions.
International collaborations have been set up to extend this research to international facilities and to improve the interpretation of the experimental results. In particular, similar experiments will be conducted in Spain, at the University of Salamanca, in collaboration with the local experimental group. Moreover, through a collaboration with the Universidad Politecnica de Madrid it will be possible to simulate the proton transport and stopping power in the compressed plasma. The modeling code uses a classic stopping power formula for ions in solid matter, and the difference between the simulated and the experimental results will evidence the differences between ion stopping in solid matter and dense plasmas. The research funding will be used both to purchase targets and diagnostics as well as to support travel expenses to international facilities and conferences.

Research Products

• [Journal Article] Direct measurements of enhanced relativistic-electron-beam energy losses in warm-dense aluminum (2015)
  • Author(s): X. Vaisseau, a. Debayle, J. J. Honrubia, S. Hulin, a. Morace,et al.
  • Journal Title: Physical Review Letters Volume: 114 Pages: 1-5
  • DOI: 10.1103/PhysRevLett.114.095004
  • Peer Reviewed / Open Access
• [Journal Article] Development of advanced X-ray Radiography for High Energy Density Physics (2014)
  • Author(s): A. Morace, L. Fedeli, D. Batani, S. Baton, F. N. Beg, S. Hulin, L. C. Jarrott, a. Margarit, M. Nakai, M. Nakatsutsumi, P. Nicolai, N. Piovella, M. S. Wei, X. Vaisseau, L. Volpe, and J. J. Santos
  • Journal Title: Physics of Plasmas Volume: 21 Pages: 102712-102717
  • DOI: 10.1063/1.4900867
  • Peer Reviewed / Open Access
• [Journal Article] Investigation of fast electron-induced K α x-rays in laser-produced blow- off plasma (2014)
  • Author(s): H. Sawada, M. S. Wei, S. Chawla, a. Morace, K. Akli, T. Yabuuchi, N. Nakanii, M. H. Key, P. K. Patel, a. J. Mackinnon, H. S. McLean, R. B. Stephens, and F. N. Beg
  • Journal Title: Physical Review E Volume: 89 Pages: 1-12
  • DOI: 10.1103/PhysRevE.89.033105
  • Peer Reviewed / Open Access
• [Journal Article] Photonuclear reaction based high-energy x-ray spectrometer to cover from 2 MeV to 20 MeV (2014)
  • Author(s): S. Sakata, Y. Arikawa, S. Kojima, T. Ikenouchi, T. Nagai, Y. Abe, H. Inoue, a. Morace, M. Utsugi, R. Kato, H. Nishimura, M. Nakai, H. Shiraga, S. Fujioka, and H. Azechi
  • Journal Title: Review of Scientific Instruments Volume: 85 Pages: 11D629-3
  • DOI: 10.1063/1.4893943
  • Peer Reviewed / Open Access
• [Journal Article] Accuracy of Compton X-ray Spectrometer Evaluated with Bremsstrahlung X Rays Generated by 6 MeV electron bunch (2014)
  • Author(s): S. Kojima, Y. Arikawa, Y. Nishimura, H. Togawa, Z. Zhang, T. Ikenouchi, T. Ozaki, A. Morace, T. Nagai, Y. Abe, S. Sakata, H. Inoue, M. Nakai, H. Nishimura and and H. A. R. Kato, S. Miyamoto, M. Yamaguchi, A. Takemoto, S. Fujioka
  • Journal Title: Review of Scientific Instruments Volume: 85 Pages: 11D634-3
  • DOI: 10.1063/1.4894447
  • Peer Reviewed / Open Access
• [Presentation] Recent LFEX laser performances in high and ultra-high contrast conditions (2015)
  • Author(s): A. Morace, A. Yogo , S. Fujioka , Y. Arikawa, S. Kojima, S. Sakata, Y. Abe, T. Nagai, S. H. Lee, Y. Taguchi, S. Tosaki, K. Matsuo, A. Sagisaka, K. Kondo, A. Pirozhkov, T. Norimatsu, T. Jitsuno, N. Miyanaga, H. Shiraga, M. Nakai, H. Nishimura, FIREX group and H. Azechi
  • Organizer: Japanese Physical Society
  • Place of Presentation: Waseda University
  • Year and Date: 2015-03-21 – 2015-03-25
• [Presentation] Improved Laser to Proton Energy Conversion Efficiency in Isolated Reduced Mass Targets (2014)
  • Author(s): A. Morace , C. Bellei, T. Bartal, L. Willingale, J, Kim, A. Maksimchuk, K. Krushelnick, M. S. Wei, P. K. Patel, D. Batani, N. Piovella, R. B. Stephens and F. N. Beg
  • Organizer: Plasma2014
  • Place of Presentation: Niigata, Japan
  • Year and Date: 2014-11-19 – 2014-11-21
• [Presentation] Plasma Mirror technology on a PW, multi-kJ class Laser for application to Fast Ignition research (2014)
  • Author(s): A. Morace, Y. Arikawa, A. Sunahara, S. Kojima, S. Fujioka, M. Nakai, H. Shiraga, H. Nishimura, A. Sagisaka, K. Ogura, A. Yogo, M Nishikino, T. Kawachi, A. S. Pirozhkov, M. Nishiuchi, M. Kando, K. Kondo. S. Tokita, J. Kawanaka, H. Jitsuno, N. Miyanaga, Y. Nakata LFEX-group, H.Azechi
  • Organizer: IAEA Fusion Energy Conference
  • Place of Presentation: Saint Petersburg, Russia
  • Year and Date: 2014-10-13 – 2014-10-17