All issues
Successor
Volume 8 (1962)
- Issue 6 Pages 647-
- Issue 5 Pages 537-
- Issue 4 Pages 433-
- Issue 3 Pages 165-
- Issue 2 Pages 97-
- Issue 1 Pages 1-
Volume 8, Issue 4
Displaying 1-4 of 4 articles from this issue
- |<
- <
- 1
- >
- >|
-
M. Yoshikawa, H. Kubo1962 Volume 8 Issue 4 Pages 433-440
Published: 1962
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSCoherent radiation of high intensity from optical masers, when concentrated into a small region, can produce violent electron oscillation and, this being converted into random motions by means of collisions, results in a rapid increase of local electron temperature. The radiation, replaced with familiar millimeter microwave, is also found to be a more efficient and more feasible diagnostic tool when the deusity of plasma is over 1015/cc.View full abstractDownload PDF (603K) -
Relaxation of an Elliptic DistributionM. Ogasawara1962 Volume 8 Issue 4 Pages 441-452
Published: 1962
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSDownload PDF (683K) -
M. Kumagai, T. Tsukishima1962 Volume 8 Issue 4 Pages 453-478
Published: 1962
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSThe rate of increase of the electron density in a pulsed microwave field (5550 Mc/s) applied to gas mixtures of neon and argon at a fixed total pressure of 100 mmHg is calculated by taking account of various possible atomic processes and an energy distribution of electrons in the mixed gases.
The electron density increases exponentially with a time constant τb in the density range smaller than 1011/cm3. The relations between τb and the relative partial pressure of argon, r, are obtained for various values of.E/p where. E/p is the ratio of the electric field strength to the total pressure of the mixed gas (in volt/cm mmHg). The value of r giving a minimum value of τb, min=9×10-7 sec is 0.01 for E/p=3, while it is 0.07 at τb, min=3.8×10-9 sec for E/p=17, A tendency is also obtained that the larger the value of E/p, the slower the inclination of τb in the τb r diagram for the range r<rm (which gives the minimum value of τb). This is explained in terms of that, with increasing E/p, the direct ionizations by collisions between electrons and neutral neon or argon atoms predominate over the ionizations by collisions between metastabe neon atoms and the neutral argon atoms, the latter process corresponding to the so-called “Penning effect”. A fairly good agreement is obtained between the calculated τ'bs and our experimental one's within a range of the experimental errors.View full abstractDownload PDF (1577K) -
N. Hokkyo1962 Volume 8 Issue 4 Pages 479-490
Published: 1962
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSThe influence of the presence of a large amplitude plasma wave eψl exp (ωet-er) on the damping of another wave (ωk, k) in a plasma is considered. It is seen that the usual Landau's damping coefficient is increased by a factor [1+eψl/hωk] 2exp [- (kD/k) 2 (eψl/hωk) 2] if e and k are related by Pe/m_??_p k/m-eψl/h, the result being due to the fact that the resonant momentum p of electrons for emission (upper sign) and absorption (lower sign) of-plasmon plasmon (ωk. k) is determined by a conservation equation W (p+h, e) +hωk-W (p.e) =0 where W=W (p, e.;ψl) is the dispersion relation of an electron of momentum p in the periodic electric field associated with the plasma wave (ωe, e). The diffusion in the velocity space of electrons in a collisionless plasma is next considered. Various features of relaxation processes of electron velocity distribution may be understood by imagining an electron undergoing a sequence of displacements (recoils) in the velocity space, each recoil being either in the backward, or in “forward” direction depending on whether the electron emits or absorbs a plasmon. The probability that the electron suffers a forward (backward) displacement by absorbing (emiting) a plasmon is governed by a distribution in (phase) velocity space of plasmons, since, for instance, electrons cannot absorb plasmons from plasmon vacuum and whenever they arrive at a region of plasmon vacuum in the velocity space after a sequence of forward displacements by successive absorption of plasmons they suddenly become incapable of sufferring further forward displacements.View full abstractDownload PDF (729K)
- |<
- <
- 1
- >
- >|