| Budget Amount *help |
¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1998: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1997: ¥1,400,000 (Direct Cost: ¥1,400,000)
|
|---|
| Research Abstract |
1) We found that there are some difficulties in the idea for plasma flow measurements proposed by Chung because of so-called recycling probrem which occurs in a real plasma device such as tokamak.
2) In this study we have developed a new method, by which such a problem successfully reduced.
3) As a new plasma flow estimation, we put a separator in front of a Mach probe : using a MHD theory including plasma viscosity, we found that the ratio of the two saturation currents, i.e. with and without the separator gives the Mach velocity or Mach number of the plasma flow.
4) In order to check the reliability of our new method, we used an independent method to measure the flow velocity, i.e. the dispersion relation of the two shear Alfven waves ; one is launched from the upper stream side, and the other is from the down stream side. From the difference between two dispersion relations, we can estimate the real flow velocity.
5) As a result, our Mach probe is found to be useful and reliable for measuring the flow velocity, within errors of experiment and of theoretical approximations. Moreover, it should be emphasized that it can also estimate the viscosity of the plasma.
|
