| Project/Area Number |
11640269
|
|---|
| 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 | Nagoya University |
|---|
Principal Investigator |
DAITO Izuru Center for Integrated Research in Science and Engineering, Nagoya University Res.Assoc., 理工科学総合研究センター, 助手 (90303594)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
IWATA Takahiri School of Science, Nagoya University, Assoc.Prof., 理学研究科, 助手 (70211761)
MORI Kunikazu School of Science, Nagoya University, Prof., 理学研究科, 教授 (70022663)
HORIKAWA Naoaki Center for Integrated Research in Science and Engineering, Nagoya University Prof., 理工科学総合研究センター, 教授 (70022697)
WAKAI Atsushi Center for Integrated Research in Science and Engineering, Nagoya University, 理工科学総合研究センター, 非常勤研究員
|
|---|
| Project Period (FY) |
1999 – 2000
|
| Project Status |
Completed (Fiscal Year 2000)
|
| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2000: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1999: ¥2,500,000 (Direct Cost: ¥2,500,000)
|
|---|
| Keywords | Nuclear Fusion / Polarized Target / Spin / NMR / 核隔合 |
|---|
| Research Abstract |
To measure the polarization dependences of cross sections of pol. ^2H(pol. D, p)^3H fusion reaction at low energies, a polarized deuteron target system was constructed. The target system requires new four components.
1. Ultra low temperature and magnetic field
Dynamic Nuclear Polarization method(DNP)requires ultra low temperature(less than 500 mK)to polarize nuclei To obtain this low temperature, new ^3He-^4He dilution cryostat was constructed. The specifications of this cryostat are 1)lowest temperature is 200 mK, 2)the cooling power is 2.6 mW at 500 mK.A super-conducting Helmholtz coil was also constructed for a magnetic field of 2.5 Tesla. The homogeneity inside the central 5 mm sphere is 10^<-4>.
2. Development of target materials
To apply for low energy nuclear experiments, target materials should be thin to suppress a heat input caused by energy losses of beam. Deuterated polyethylene(CD_2)was used as a target material because it is easy to forming thin foil. We employed two methods
… More
to product paramagnetic center in target material. One is a chemical dope of TEMPO, which has a paramagnetic center. The result of polarization achieved is 11 %. The other way is irradiation by electron beam to cut chemical bonds between C-C and C-D.We obtained the polarization of 16.7 % by irradiation.
3. NMR system
Because of forming thin foil from material and a small volume of the uniform area of magnetic field, it is necessary construct new NMR system, which has a good sensitivity for small NMR signal. New method is named "SRT" (Synchronous Resonance Tuning). The SRT is realized by modulating the reverse bias voltage of a varactor diode to fulfill the resonance condition ω=√LC for each frequency of the sweep. By using this SRT, we can measure the output voltage of NMR circuit at the peak of Q-curve. Additionally, the transmission cable in LCR circuit was removed to avoid the frequency dependence of peak voltage of Q-curve.
The Signal to Noise ratio becomes better than that of the conventional Q-meter method. Less
|
