Strong field inverse bremsstrahlung via a Lorentz model

Abstract

The commonly employed results of Silin for inverse bremsstrahlung with strong field corrections are obtained in a simple manner from a Lorentz collision operator. The effective collision frequencies for linearly and circularly polarized light are given for arbitrary pump strength.

Heating mechanisms in radio-frequency-driven ultracold plasmas

“…Choosing further σ = 1 mm, T e = 1 K, and n = 10 8 cm −3 , Eqs. (2)- (8), (12), (16), and (25) give P ei /k B = 4 × 10 2 K/μs and R/n e = 3 × 10 −7 μs −1 , while the collisionless absorption rate is vanishingly small. Thus collisional absorption is expected to heat the plasma to the 100 K scale during the expansion time of the plasma, while the chance that an individual electron recombines is very small.…”

“…Using these values in Eqs. (2)- (8), (16), and (25) gives absorption rates per electron of P ei /k B = 3 K/μs and P p /k B = 0.002 K/μs at the highest reported frequency and amplitude. Considering the electron temperature of 100 K and the typical plasma expansion time of microseconds, these low absorption rates will not influence the plasma temperature and expansion much.…”

“…Here, T e is the electron temperature of the plasma. The effective collision frequency has been calculated first by classical kinetic theory using the Landau collision integral [15,16]. The result can be written as [21] …”

“…We consider two mechanisms by which the UCP can directly absorb energy from the rf field: collisional absorption and collisionless absorption due to the finite size of the plasma. The first of these has been studied extensively already in other contexts [15][16][17][18][19][20][21][22][23][24][25]. In Sec.…”

Collisional absorption of laser light in under-dense plasma: The role of Coulomb logarithm

“…In all other works, [1][2][3][4]9,[12][13][14] the timedependency in the collision frequency was ignored, and an average ei was used which can be obtained from the BM when ei ðtÞ is averaged with the oscillatory energy v 2 os ðtÞ=2 [using v os ðtÞ ¼ v 0 sinðxtÞ] of an electron over one laser period T 0 ¼ 2p=x. In the limit of v 0 =v th ( 1, the BM was found to reproduce the results of Silin.…”