Interprétation des résultats des « jets » des mésons

Hoang, T. F.

doi:10.1051/jphysrad:01954001505033700

Cited by 7 publications

(6 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, Morrison, Olbert, and Rossi 25 have shown that in order for the interstellar motions to result in the observed energy spectrum as a consequence of (21), as originally suggested by Fermi,7 it is necessary that the interstellar velocities be of the order of 120 km/sec, reversing their sign every light year. But it is readily shown 26 that the viscous losses of such small-scale and violent motions are prohibitive: The cosmic-ray energy density of 10~1 2 erg/cm 3 with a life of the order of 4X10 6 years requires an energy input of the order of 10~~2 6 erg/cm 3 /sec; the mechanism of Oort and Spitzer 27-30 may perhaps supply sufficient energy to the interstellar motions for maintaining the input to the cosmic rays, but the mechanism is entirely inadequate to support the viscous losses, which are 100 times greater than 10~2 6 erg/cm 3 /sec.…”

Section: A Isolated Moving Inhomogeneitiesmentioning

confidence: 93%

“…In the original version of Fermi's mechanism, 7 wherein the cosmic-ray particles were in a space filled with separate and independently moving clumps of magnetic field, the mean fractional energy gain per collision of a relativistic particle with a moving clump of field, was…”

Section: A Isolated Moving Inhomogeneitiesmentioning

confidence: 99%

“…We consider a charged particle with velocity w whose radius of curvature in Bo is small compared to the pulse width L It follows from (19) that in the frame of reference in which a given pulse is stationary, the angle of pitch 6 (the angle between w and the total magnetic field) varies in the well-known manner 7 : Penetration of the pulse occurs when 9 is sufficiently small that 6<9 C in the uniform field between pulses, where sm%=Bo/B max .…”

Section: B Continuous Wavesmentioning

confidence: 99%

“…We suppose that po is the uniform hydrostatic pressure when the system is unperturbed, and that the fluid satisfies the equation of state P = po(p/p*) 7 .…”

Section: Appendixmentioning

confidence: 99%

“…3 velocities apparently occurs in regions as dense as the solar chromosphere, 6 as active as supernovae, [3][4][5] and as large-scale and cool as the interstellar medium. 7 Presumably, therefore, the process, or processes, of acceleration are not at all a freak occurrence, but must arise from some naturally and not uncommonly occurring dynamical condition.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Origin and Dynamics of Cosmic Rays

Parker

1958

Phys. Rev.

118

View full text Add to dashboard Cite

direction using the 180-Mev bremsstrahlung. Backgrounds due to cosmic rays varied from about 25% at 6=0° to about 2% at 6=90°. Other backgrounds, mostly due to accidental coincidences, were determined by measurements below counting threshold at 150 Mev. At 0=90° these backgrounds were about 25%. At all other angles they were 10% or less. Several runs were taken at each angle. An attempt was made to alternate the runs on each side of 0=45° to reduce systematic errors. These data have been corrected for the expected geometrical asymmetry discussed above.The angular distribution of Fig. 4 indicates no marked asymmetry. A least squares fit of the form f(6) = 1+a cos 4 0 gives a value of a = 0.025±0.090.As a consequence of our inability to observe directly the origin of a cosmic-ray particle, we begin the development with a discussion of the limitations within which we can construct a cosmic-ray accelerator mechanism. We find that we are allowed only the betatron effect and the Fermi mechanism. We review some of the many variations of these mechanisms which are to be found in the literature. Then it is shown that trains of oppositely moving hydromagnetic waves of large amplitude and with sharp crests can accomplish large and continued particle accelerations which are adequate to maintain the observed galactic cosmic-ray held. The large acceleration arises as a consequence of the simple fact that each wave tends to sweep up the cosmic-ray particles before it, so that head-on collisions of particles with waves are much more common than overtaking collisions. It is pointed out that the sharp crests of the waves are a natural consequence of the observed supersonic mass motions. Therefore, the acceleration by oppositely moving waves does not depend upon any special wave form, and we suggest that it is the naturally occuring acceleration process. * Assisted in part by the Office

show abstract

Section: A Isolated Moving Inhomogeneitiesmentioning

confidence: 93%

Section: A Isolated Moving Inhomogeneitiesmentioning

confidence: 99%

Section: B Continuous Wavesmentioning

confidence: 99%

“…We suppose that po is the uniform hydrostatic pressure when the system is unperturbed, and that the fluid satisfies the equation of state P = po(p/p*) 7 .…”

Section: Appendixmentioning

confidence: 99%