| Project/Area Number |
12440113
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
物理学一般
|
|---|
| Research Institution | Himeji Institute of Technology |
|---|
Principal Investigator |
ISHIKAWA Kiyoshi Faculty of Science, Himeji Institute of Technology, Associate Professor, 理学部, 助教授 (00212837)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
TAKAGI Yoshihiro Faculty of Science, Himeji Institute of Technology, Professor, 理学部, 教授 (80106161)
|
|---|
| Project Period (FY) |
2000 – 2001
|
| Project Status |
Completed (Fiscal Year 2001)
|
| Budget Amount *help |
¥16,600,000 (Direct Cost: ¥16,600,000)
Fiscal Year 2001: ¥5,900,000 (Direct Cost: ¥5,900,000)
Fiscal Year 2000: ¥10,700,000 (Direct Cost: ¥10,700,000)
|
|---|
| Keywords | optical pumping / Hyperpolarized noble-gas / laser narrowing / high power laser diode / low field magnetic resonance / MR imaging / 高偏極希ガス / アルカリ金属原子 / 磁気共鳴 / 狭帯域化レーザー |
|---|
| Research Abstract |
In this project we intend the laser spectroscopy of hyperpolarized noble-gas atoms additionally using synchrotron radiation and magnetic resonance imaging. The efficient polarization of nuclear spin will be achieved by the narrowing of high power laser diode. We believe that the novel method of nuclear polarization is developed by studying the interaction of noble-gas atoms with dielectric or magnetic surface.
To detect the resonance signal of nuclear spins at low field (10 mT) we developed the equipment of low frequency (10 kHz - 10 MHz) magnetic resonance. By the optical pumping of Rb atoms, the polarization at 1 % could be detected for gas phase Xe atoms. We can obtained the high polarization and the efficient transfer of angular momentum from photon to Xe atom by the narrowing of high power laser diode, developed last year. The laser power is 2 W, and ten times weaker than the previously reported values. This year we stabilized the laser frequency and amplified the narrowed laser by the broad area laser array. This laser system promises the high efficiency of production of hyperpolarized noble gases. By removing Rb atoms, the polarization at 0.1 % is detected. It is possible to obtain the higher polarization for pure Xe gas, so we need to find the condition of lossless transfer of Xe atoms in order to detect the interaction with dielectric surface.
We reported the electron spin dynamics of dense Rb atoms which drastically depends on the polarization, the magnetic field, the atom density, and the pulse area of RF field. In the paper we demonstrated experimentally and theoretically the decay of atomic coherence is due to the spin-exchange interaction of dense Rb atoms.
|
