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Volume 12 (1964)
- Issue 6 Pages 510-
- Issue 5 Pages 386-
- Issue 4 Pages 285-
- Issue 3 Pages 219-
- Issue 2 Pages 81-
- Issue 1 Pages 1-
Volume 12, Issue 6
Displaying 1-4 of 4 articles from this issue
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Kiyoshi Yatsui, Uichi Kubo, Yoshio Inuishi1964 Volume 12 Issue 6 Pages 510-527
Published: 1964
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSThe diffusion rate of ions in a plasma is studied with-respect to a longitudinal magnetic field in the range 0-1, 000 gauss (lower than the critical field for screw instability) from measurement of the diffusion current on the wall of the discharge tube.
Comparing with the classical ambipolar diffusion theory, a small deviation is found when the magnetic field comes to a certain value.
In addition, we investigated an oscillation of the plasma in a magnetic field.
As a result of these studies, it is turned out that the plasma becomes unstable suddenly to produce low frequency oscillations at a certain magnetic field where enhancement of the diffusion coefficient appears.
It seems to suggest that there is another kind of critical magnetic field for instability under the critical field for screw instability.View full abstractDownload PDF (1358K) -
Keiicni Hirano1964 Volume 12 Issue 6 Pages 528-555
Published: 1964
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSA pinched gun of linear type has been investigated as the sourse of high energy plasma jet.
The gun employs alow indicctance (18 mμH) power supply and pulsive aamition of gas into vacuum by a fast acting valve mounted on the bottom copper disk electrode.
Sufficcently high speed (-108 cm/sec) plasma jet of hydrogen gas has been Obtained when the gas diffusion delay time (t) is short.
It was-found that the performance of the plasma gun is closely related to the pinch effect taking place in the gun.
The ratio of the plasma speed to the mean pinching speed of the gun depends only on (t) and does not on the total amount of admitted gas. We learned that the meam pinchingspeed follows Rosenbluth's theory and was independent on (t), while it was only the function of average gas density in the gun.
For small (t), H is said to be constant about (t) and starting voltage of plasma driving condensers, and decreases suddenly for some critical value of (t) which becomes larger when the starting voltage of the condensers are higher.View full abstractDownload PDF (1701K) -
K. Shinano1964 Volume 12 Issue 6 Pages 556-563
Published: 1964
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSExperimeuts were done in order to know interactions between high density hydrogen plasmas and magnetic fields. (cusped field, single coil field and mirror field)
Behaviors of injected plasma were studied usuig streak photographs taken through a long slit imaged at the axis of the straight vacuum vessel.
Experimental results are as follows.
1) Single coil field
Plasma decreases its axial velocity in encountering strong field, and penetrates through it even when the field strenght is more than 8, 000 gauss.
2) Cusped field
After penetrating through the entrance cusp, plasma takes back its original speed and goes through the zero region of the field with this constant velocity up to a certain point where the velocity changes abruptly.
After then plasma moves toward the exit cusp and is reftected by a 6000-gauss field.
3) Mirror field
Plasma injected into mirror field is not trapped.View full abstractDownload PDF (779K) -
Ikuo Kaji, Masafumi Kito, Yasutomo Ozawa1964 Volume 12 Issue 6 Pages 564-572
Published: 1964
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSA dispersion relation for transverse plasma waves propagating along a uiform external magnetic field is obtained in the form of an algebric equation, for an anisotropic velocity distribution.
[{(ω/ωp) 2- (kc/ωp) 2} · {ω/ωp±Ω/ωp} -ω/ωp] × [ω/ωp±Ω/ωp] =1/2 (ο⊥/c) 2 (kc/ωp) 2,
where ωp is the plasma frequency, Ω the cyclotron frequency, and ο2⊥=2kT⊥/m.
When the range of vainable kc/ωp and parameters σ⊥/ c, , Ω/ωp is taken such that kc/ωp = 0, 0.5, …, 9.5, 10,
σ⊥/c = 2n×10-1; n= 0, -1, …, -7, -8, -∞,
Ω/ωp= 2n; n=4, 3, …, 0, …, -7, -8, -∞
the dispersion relation is solved by the use of the digital computer (HIPAC-103). For the right-handed circularly polarized waves, the dispersion curves are described and the stable region of transverse waves are determined for several parameters. The dispersion curves consist of two modes of electromagnetic waves, and of modes of growing and damped waves which oscillate in cyclotron frequency. In the absence of the external magnetic field, the growing waves with cyclotron frequency become spontaneously growing waves which was obtained by E.S. Weibel.View full abstractDownload PDF (735K)
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