Hostname: page-component-cd9895bd7-8ctnn Total loading time: 0 Render date: 2024-12-23T19:42:16.106Z Has data issue: false hasContentIssue false

Effects of laser profiles on fast electron generation under the same laser energy

Published online by Cambridge University Press:  29 May 2013

M. Hata*
Affiliation:
Department of Physics, Nagoya University, Nagoya, Japan
H. Sakagami
Affiliation:
Fundamental Physics Simulation Research Division, National Institute for Fusion Science, Toki, Japan
T. Johzaki
Affiliation:
Mechanical Systems Engineering, Hiroshima University, Higashihiroshima, Japan
H. Nagatomo
Affiliation:
Institute of Laser Engineering, Osaka University, Suita, Japan
*
Address correspondence and reprint requests to: M. Hata, Department of Physics, Nagoya University, Nagoya 464-8602, Japan. E-mail: [email protected]

Abstract

In fast ignition, optimization of laser profile for core heating is one approach to ignite the core. However, the profile is not so optimized and its effects on fast electron characteristics are not fully clarified yet. The laser profile is optimized under the condition of same laser energy because laser energy is restricted in experiments. Therefore, we investigate effects of laser profile on fast electron generation under the condition of same laser energy. In this paper, each effect of laser temporal and spatial profile is estimated independently using two-dimensional Particle-In-Cell simulations. We conclude that lower intensity laser suitable for fast ignition under the limit of simulated parameters when energy of laser is same because efficient core-heating electrons are much generated and divergence angle is smaller in low-intensity case compared to high-intensity case.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2013 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Azechi, H. & The FIREX Project. (2006). Present status of the FIREX programme for the demonstration of ignition and burn. Plasma Phys. Cont. Fusion 48, B267B275.CrossRefGoogle Scholar
Beg, F., Bell, A., Dangor, A., Danson, C., Fews, A., Glinsky, M., et al. (1997). A study of picosecond laser-solid interactions up to 1019 W/cm2. Phys. Plasmas, 4, 447.CrossRefGoogle Scholar
Green, J., Ovchinnikov, V., Evans, R., Akli, K., Azechi, H., Beg, F., et al. (2008). Effect of laser intensity on fast-electron-beam divergence in solid-density plasmas. Phys. Rev. Lett., 100, 15003.Google ScholarPubMed
Haines, M., Wei, M., Beg, F. & Stephens, R. (2009). Hot-electron temperature and laser-light absorption in fast ignition. Phys. Rev. Lett., 102, 45008.CrossRefGoogle ScholarPubMed
Hata, M., Sakagami, H., Sunahara, A., Johzaki, T. & Nagatomo, H. (2012). Effects of ch foam preplasma on fast ignition. Laser Part. Beams 30, 189197.CrossRefGoogle Scholar
Johzaki, T., Nagatomo, H., Sunahara, A., Cai, H., Sakagami, H., Nakao, Y., et al. (2011). Pre-plasma effects on core heating and enhancing heating efficiency by extended double cone for firex. Nucl. Fusion 51, 073022.CrossRefGoogle Scholar
Key, M. (2007). Status of and prospects for the fast ignition inertial fusion concept. Phys. plasmas 14, 055502.CrossRefGoogle Scholar
Kodama, R., Shiraga, H., Shigemori, K., Toyama, Y., Fujioka, S., Azechi, H., et al. (2002). Nuclear fusion: fast heating scalable to laser fusion ignition. Nat. 418, 933934.CrossRefGoogle ScholarPubMed
Mima, K., Sunahara, A., Shiraga, H., Nishimura, H., Azechi, H., Nakamura, T., et al. (2010). Firex project and effects of self-generated electric and magnetic fields on electron-driven fast ignition. Plasma Phys. Contr. Fusion 52, 124047.CrossRefGoogle Scholar
Miyanaga, N., Azechi, H., Tanaka, K., Kanabe, T., Jitsuno, T., Kawanaka, J., et al. (2006). 10-kj pw laser for the firex-i program. Phys. 133, 8187.Google Scholar
Murakami, M., Nagatomo, H., Azechi, H., Ogando, F., Perlado, M. & Eliezer, S. (2006). Innovative ignition scheme for ICFimpact fast ignition. Nucl. Fusion 46, 99.CrossRefGoogle Scholar
Nakamura, T.Mima, K., Sakagami, H., Johzaki, T. & Nagatomo, H. (2008). Generation and confinement of high energy electrons generated by irradiation of ultra-intense short laser pulses onto cone targets. Laser Part. Beams 26, 207212.CrossRefGoogle Scholar
Norreys, P., Scott, R., Lancaster, K., Green, J., Robinson, A., Sherlock, M., et al. (2009). Recent fast electron energy transport experiments relevant to fast ignition inertial fusion. Nucl. Fusion 49, 104023.CrossRefGoogle Scholar
Pukhov, A., Sheng, Z. & Meyer-Ter-Vehn, J. (1999). Particle acceleration in relativistic laser channels. Phys. Plasmas 6, 28472854.CrossRefGoogle Scholar
Pukhov, A. & Vehn, J. Meyer-ter. (1997). Laser hole boring into overdense plasma and relativistic electron currents for fast ignition of icf targets. Phys. Rev. Lett., 79, 26862689.CrossRefGoogle Scholar
Roth, M., Cowan, T., Key, M., Hatchett, S., Brown, C., Fountain, W., et al. (2001). Fast ignition by intense laser-accelerated proton beams. Phys. Rev. Lett., 86, 436439.CrossRefGoogle ScholarPubMed
Sakagami, H., Johzaki, T., Nagatomo, H. & Mima, K. (2009). Generation control of fast electron beam by low-density foam for firex-i. Nucl. Fusion 49, 075026.CrossRefGoogle Scholar
Sakagami, H., Sunahara, A., Johzaki, T. & Nagatomo, H. (2011). Effects of long rarefied plasma on fast electron generation for firex-i targets. Laser Part. Beams 30, 103.Google Scholar
Shiraga, H., Fujioka, S., Nakai, M., Watari, T., Nakamura, H., Arikawa, Y., et al. (2011). Fast ignition integrated experiments with gekko and lfex lasers. Plasma Phys. Contr. Fusion 53, 124029.CrossRefGoogle Scholar
Sunahara, A., Johzaki, T., Nagatomo, H. & Mima, K. (2012). Generation of pre-formed plasma and its reduction for fast-ignition. Laser Part. Beams, 30, 95.CrossRefGoogle Scholar
Tabak, M., Clark, D., Hatchett, S., Key, M., Lasinski, B., Snavely, R., et al. (2005). Review of progress in Fast Ignition. Phys. Plasmas, 12, 057305.CrossRefGoogle Scholar
Tabak, M., Hammer, J., Glinsky, M.E., Kruer, W.L., Wilks, S.C., Gampbell, E.M., et al. (1994). Ignition and high gain with ultrapowerful lasers. Phys. Plasmas 1, 16261634.CrossRefGoogle Scholar
Wilks, S., Kruer, W., Tabak, M. & Langdon, A. (1992). Absorption of ultra-intense laser pulses. Phys. Rev. Lett. 69, 13831386.CrossRefGoogle ScholarPubMed