CW Ion-Argon-Lasers with the Supersonic Transverse Gas Flow

High-power CW UV Ar++laser with a transverse gas flow

“…The acceleration of atoms by a discharge (figure 4) seems to have two causes: gas heating and ionization, which lead to the depletion of atoms. The high value of atomic velocity at the high current V.: = 4.5 X lo4 cm s-' was also measured in an earlier paper [5]. However, this fact cannot be used for proof of SSF.…”

“…However, this fact cannot be used for proof of SSF. We have measured the pressure difference on the throat of SSNS used in [4,5] and have found that supersonic flow cannot be obtained without discharge in a wide pressure range (0.1 to 10 Torr). The error in previous works [4,5] lies in the fact that the pressure was measured far from the discharge channel (near the leak valve) and the resistance of upstream tubes was not taken into account.…”

“…Under the strong ionization condition it is necessary to take the depletion of atoms at the discharge axis [9] into account. The transverse flow of atoms may lead to the asymmetry of the discharge [5,7]. DTF theory [lo] gives a connection between mass How rate Q , asymmetry of the discharge AF and flow-ionization parameter y (2y is the ratio between the How of ions from the plasma and the flow of atoms to the plasma)…”

“…In the first experiments the sections used had the planar supersonic nozzles (SSN) as described in [4,5]. However, it was found that there is no supersonic flow (SSF) in such a construction.…”

“…The flow velocity of atoms in the discharge V: has been determined from the Doppler shift of the atomic line at 4158 8, [5].…”