Electron Accelerators and Applications

1F - Industrial and Medical Accelerators

Paper Title Page
TUP063 Development of a New Highly Bright X-ray Generator 539
  • S. Ohsawa, M. Ikeda, N. Sakabe, T. Sugimura
    KEK, Ibaraki

A new type of rotating anticathode X-ray generator has been developed, in which the electron beam irradiates the inner surface of a U-shaped anticathode. A high-flux electron beam is focused on the inner surface by optimizing the shape of the bending magnet. In order to minimize the sizes of the X-ray source, the electron beam is focused strongly in a short distance by the bending magnet which is small and is close to the rotating anticathode. The power of the electron beam can be increased to the point at which the irradiated part of the inner surface is melted, because a strong centrifugal force fixes the melted part on the inner surface. We have achieved emission of X-rays 10 times more brilliant than can be attained by a conventional rotating anticathode. The development is still in progress. New results will be reported in detail.

TUP064 Nuclear Reaction Analysis by Using Quasi-Elastic Scattering of Ultra Low Intensity Electron Beams 542
  • R. Taniguchi, T. Kojima, S. Okuda, R. Sasaki
    Osaka Prefecture University, Sakai

Energetic electron beams higher than several MeV occasionally induce direct nuclear reactions with the target nuclei. These processes are attributed to the quasi-elastic scattering of electrons (e,e') with the target nuclei and similar to the photo-nuclear reactions. These reactions are considered to be useful for the non-destructive analysis of heavy elements such as U and Th. In addition, a two-dimensional analysis is realized only by scanning of electron beam. On the other hand, the huge X-ray burst caused by the bremsstrahlung with the electron pulse bombardment is the most harmful phenomenon for the radiation measurement system. In this study, an ultra low intensity electron beam was used for relieving the problem, which has been developed by modifying an electron linear accelerator. The minimum beam charge about several aC/pulse has been achieved at the present. Consequently, the neutron emitted by Pb(e,e'n)Pb reaction was measured successfully by the use of the low intensity beams. The linearity between the neutron count and the concentration of Pb in the target was verified experimentally.

TUP065 Demonstration of Multi-Pulse X-ray Generation via Laser-Compton Scattering Using Pulsed-Laser Super-Cavity 545
  • K. Sakaue, M. Washio
    RISE, Tokyo
  • S. Araki, M.K. Fukuda, Y. Higashi, Y. Honda, T. Taniguchi, N. Terunuma, J. Urakawa
    KEK, Ibaraki
  • N. Sasao
    Kyoto University, Kyoto

Funding: Work supported by a Grant-In-Aid for Creative Scientific Research of JSPS (KAKENHI 17GS0210) and a Grant-In-Aid for JSPS Fellows (19-5789)
A compact and high quality X-ray source is required for various field, such as medical diagnosis, drug manifacturing and biological sciences. Laser-Compton based X-ray source that consist of a compact electron storage ring and a pulsed-laser super-cavity is one of the solutions of a compact X-ray source. Pulsed-laser super-cavity has been developed at Waseda University for a compact high brightness X-ray source. The pulsed-laser super-cavity enables to make high peak power and small waist laser at the collision point with the electron beam. 357 MHz mode-locked Nd:VAN laser pulses can be stacked stably in a 420 mm long Fabry-Perot cavity with "burst mode", which means stacking of electron beam synchronized amplified pulses in our R&D. In view of this successful result, we have started an X-ray generation experiment using a super-cavity and a multi-bunch electron beam at KEK-LUCX. Recently, the demonstration experiment between the burst mode pulsed-laser super-cavity and the 100bunch multi-bunch electron beam is successfully performed. Development of the super-cavity and the experimental results of X-ray generation will be presented at the conference.

TUP066 Commissioning of 10-MeV L-band Electron Linac for Industrial Applications 548
  • S.H. Kim, M.-H. Cho, W. Namkung, H.R. Yang
    POSTECH, Pohang, Kyungbuk
  • S.D. Jang, S.J. Park, Y.G. Son
    PAL, Pohang, Kyungbuk
  • J.-S. Oh
    NFRI, Daejon

Funding: This work is supported by KAPRA and POSTECH Physics BK21 Program.
An intense L-band electron linear accelerator is now being commissioned at CESC (Cheorwon Electron-beam Service Center) for industrial applications. It is capable of producing 10 MeV electron beams with 30 kW average beam power. For a high-power capability, we adopted the traveling-wave structure operated with the 2π/3 mode at 1.3 GHz. The structure is powered by a 25 MW pulsed klystron with 60 kW average rf power. The rf pulse length is 7 μs while the beam pulse length is 6 μs due to the filling time in the accelerating structure. The accelerating gradient is 4.2 MV/m at the beam current of 1.45 A which is the fully beam-loaded condition. In this paper, we present details of the accelerator system and commissioning results.

TUP068 Project of a Neutron Source Based on the Sub-Critical Assembly Driven by Electron Linear Accelerator 551
  • I.M. Karnaukhov, V. Azhazha, A.N. Dovbnya, A.S. Kostromin, V.E. Krasnorutzkiy, I.M. Neklyudov, S.A. Perezhogin, S. Soldatov, A.Y. Zelinsky
    NSC/KIPT, Kharkov
  • I. Bolshinsky
    Idaho National Laboratory, Idaho
  • M.Y.A. Gohar
    ANL, Argonne

Today accelerator driven subcritical assembly is candidate for the next generation of energy-generating nuclear facility, which could provide safe energy production, burning of transuranium elements and transmutation of radionuclides. Use of the electron beam with particle energy up to 150-200 MeV secures several advantages. Electron linear accelerators are much cheaper compared to hadron accelerators. Homogeneous irradiation of the assembly with neutrons could be provided. NSC KIPT together with ANL develops the project of a neutron source based on the sub-critical assembly driven by electron linear accelerator. Energy of electrons is 100-200 MeV. The target and assembly design is optimized to maximize the neutron source intensity with subcriticality of 0.98. Accelerator on average beam power of 100 kW, with repetition rate up to 300 Hz and pulse duration of 3,2 ms is under development. Transportation line should provide beam transfer with minimal losses of electrons and should form homogeneous distribution of the particle density at the target. Maximal value of a neutron flux is Fm=2x1013 n/(cm2s), and power of energy release in the result of nuclei fission is Pm≈ 100 kW.

TUP069 Low Energy Photoemission Electron Source for Applications in THz Radiation Production and Time-Resolved Electron Microscopy 554
  • N. Vinogradov, P. Piot, C.R. Prokop
    Northern Illinois University, DeKalb, Illinois
  • J.W. Lewellen, J. Noonan
    ANL, Argonne

Funding: Work supported by the Department of Education under contract P116Z010035 with Northern Illinois University.
A simple, inexpensive, and compact low-energy (~20 KeV) photoemission electron source was designed, built and recently commissioned. It uses a commercial ultraviolet photocathode drive laser producing 3 ns RMS pulse. The source will eventually be used to drive a table-top THz radiation source, based on the Smith-Purcell free-electron laser scheme, and could also have potential application to time-resolved electron microcopy. We present experimental measurements of the photoemitted electron beam and numerical simulations of the anticipated parameters. We also discuss the generation of flat beams required to efficiently drive the THz radiation source.