Development of a plasma channel for laser-electron beam compton scattering

• Project/Area Number: 14540273
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 素粒子・核・宇宙線
• Research Institution: Tokyo Metropolitan University
• Principal Investigator: KUMITA Tetsuro Tokyo Metropolitan U., Physics, Assistant Prof., 大学院・理学研究科, 助手 (30271159)
• Co-Investigator(Kenkyū-buntansha): IRAKO Mitsuhiro Tokyo Metropolitan U., Physics, Assistant Prof., 大学院・理学研究科, 助手 (60087004)
• Project Period (FY): 2002 – 2003
• Project Status: Completed (Fiscal Year 2003)
• Budget Amount: ¥3,400,000 (Direct Cost: ¥3,400,000); Fiscal Year 2003: ¥1,200,000 (Direct Cost: ¥1,200,000); Fiscal Year 2002: ¥2,200,000 (Direct Cost: ¥2,200,000)
• Keywords: Laser Compton scattering / plasma channel / plasma wakefield / plasma acceleration / レーザー・コンプトン散乱 / プラズマ航跡場加速 / CO_2レーザー / 電子加速器 / コンプトン散乱 / プラズマ

Research Abstract

Development of high-intensity, short-pulse, and compact X-ray sources is required for various fields of scientific, industrial, and medical applications. One of the most promising methods for producing such an X-ray beam is known as Laser Synchrotron Source (LSS), which utilizes relativistic Compton scattering via interaction between high-power pulsed laser and electron beams.
We demonstrated production of 1.7×10^8 X-ray photons/pulse with the pulse duration of 3.5 psec using a 14 GW CO_2 laser and a 60 MeV electron beam provided at the Brookhaven National Laboratory.
In this experiment, pulse duration of the CO_2 laser is 180psec while pulse duration of the electron beam is 3.5psec. Thus, only a small portion of the laser beam contributes X-ray production because Rayleigh length of the focused laser beam, which is about a millimeter, is much shorter than the pulse duration.
Use of a plasma channel to confine the laser-electron interaction can extend the interaction region over several ce ntimeters and thus high intensity X-rays can be produced with relatively long pulse laser. We used a plasma channel produced from discharge in a polypropylene capillary, which was developed by a group of Hebrew University.
We successfully transmitted the CO_2 laser through a 25-mm plasma channel with a transverse diameter of about 100 μm, about same size as the focal spot. During transmission of the electron beam through the plasma channel, a plasma wakefield acceleration was observed. A portion of the 60MeV electron beam was accelerated by 0.6MeV in a 17-mm plasma channel. It corresponds to an average acceleration gradient of 35MeV/m.
We studied this effect by using OOPIC (Object-Oriented Particle-In-Cell), which is a simulation program developed by UC Berkeley utilizing the Particle-In-Cell method.
The maximum acceleration of 0.5MeV was obtained in the simulation for homogeneous plasma of 10^<15> cm^<-3>. We conclude the plasma wakefield acceleration in the experiment was reproduced in the OOPIC simulation.

Research Products

• [Journal Article] Transmission of high-power CO_2 laser pulses through a plasma channel (2003)
  • Author(s): I.V.Pogorelsky, T.Kumita 他
  • Journal Title: Applied Physics Letters 83 Pages: 3459-3461
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Cohesive Acceleration and Focusing of Reletiristic Electrons in Overdense Plasma (2003)
  • Author(s): V.Yekimenko, T.Kumita 他
  • Journal Title: Physical Review Letters 91
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Transmission of high-power CO_2 laser pulses through a plasma channel (2003)
  • Author(s): I.V.Pogorelsky, I.V.Pavlishin, I.Ben-Zvi, T.Kumita, Y.Kamiya, T.Hirose, B.Greenberg, D.Kaganovich, A.Zigler, N.Andreev, N.Bobrova, P.Sasorov
  • Journal Title: Appl.Phys.Lett. 83 Pages: 3459-3461
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Cohesive Acceleration and Focusing of Relativistic Electrons in Overdense Plasma (2003)
  • Author(s): V.Yakimenko, I.V.Pogorelsky, I.V.Pavlishin, I.Ben-Zvi, K.Kusche, Yu.Eidelman, T.Hirose, T.Kumita, Y.Kamiya, J.Urakawa, A.Zigler, B.Greenberg
  • Journal Title: Phys.Rev.Lett. 91
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] V.Yakimenko, T.Kumita 他: "Cohesive Acceleration and Focusing of Relativistic Electrons in Overdense Plasma"Physical Review Letters. 91. 014802-1-014802-4 (2003)
• [Publications] I.V.Pogorelsky, T.Kumita 他: "Transmission of high-powr CO_2 laser pulses through a plasma channel"Applied Physics Letters. 83. 3459-3461 (2003)