Ed. by T. Watanabe
Theoretical Study for ICRF Sustained LHD Type p-^11B Reactor
Date of publication:
p-^11B reactor, advanced fusion, D-^3He reactor, ignition condition, fusion reaction rate, quasilinear plateau distribution, ^4He confinement, ^4He exhaust, ICRF
At present, the energy sources are diversifying as shown in the spread of wind-power generation and the use of biomass energy. But, the quantitative increase of the energy consumed is always accompanied by the shift to a more clean and environmentally friendly energy resource. This will be a invariable principle proved by the history of mankind and will also apply to the nuclear fusion research. The fuel which can most easily sustain a thermonuclear reaction is a mixture of deuterium (D) and tritium (T). Notwithstanding the substantial advantages, the D-T reaction has several drawbacks produced by T breeding and fast neutron handling. Therefore, research on advanced nuclear fusion fuels continues. Proton-Boron fusion reactor (p-^11 B Reactor) p + ^11B rightarrow 3 alpha + 8.7 MeV probably offers the ultimate energy resource on the earth, because, * the fuels ( Proton and Boron) are ubiquitous on the earth, and * fast neutrons are not generated. It has been, however, considered, in the Proton-Boron fusion reactor that bremsstrahlung power loss is too large to satisfy the ignition condition, because the atomic number of boron is so large (Z_B = 5). But, the progress of LHD experimental and theoretic.al studies have brought, a new prospect for the Proton-Boron fusion reactor. *Production and confinement of high-energy particles by ICRF heating in the LHD. *Possibility of high beta plasma confinement in LHD. ICRF can sustain the high-energy proton to the optimal level for the fusion reaction, and can be Controlled not to produce the unnecessary extra-high energy proton which produce slow neutrons by the side-reaction. This is a summary of the workshop on " Theoretical Study for ICRF Sustained LHD Type p-^11B Reactor " held in National Institute for Fusion Science (NIFS) on .July 25, 2002. In the workshop, study of LHD type D-^3He reactor is also reported. A review concerning the advanced nuclear fusion fuels is also attached. This review was reported at the workshop of last year. The development of the p-^11B reactor research which uses the LHD magnetic field configuration has been briefly summarized in s1. In s2, an integrated report on advanced nuclear fusion fuels is given. Ignition conditions in a D-^3He helical reactor are summarized in s3. 0-dimensional particle and power balance equations are solved numerically assuming the ISS95 conflnement law including a confinement factor (gamma HH). It is shown that high average beta plasma confinement, a large confinement factor(gamma HH > 3) and the hot ion mode (T_i/T_e > 1.4) are necessary to achieve t,he ignition of the D-^3He helical reactor. Characteristics of ICRF sustained p-^11B reactor are analyzed in s4. The nuclear fusion reaction rate < (sigma upsilon > is derived assuming a quasilinear plateau distribution function (QPDF) for protons, and an ignition condition of p-^11B reactor is shown to be possible.