Gautam C. Patil

Switching of a TEA CO 2 laser with its own UV emitting parallel spark channels

The efficient operation of a TEA CO(2) laser wherein the parallel spark channel preioniser of the laser itself functioned as a switch is reported. Simultaneous closure of the parallel gaps without an external switch has been achieved by ballasting them with mutually coupled inductances. The repetitive operation capability of such a laser is also discussed.

Simultaneous closure of multiple high voltage parallel spark channels without switch: A parametric study

Results of a detailed parametric study of a self-switched mutually inductively coupled high voltage parallel spark preionizer are presented. The maximal behavior exhibited by the breakdown voltage of the parallel gaps with respect to the number of mutually coupled turns has been explained. It has been found that there exists a threshold rise time of the current pulse beyond which simultaneous closure of the parallel gaps is not possible and that this threshold value is independent of the nature and geometry of the cores used for the mutual coupling. The degree of simultaneity of the closure of the self-switched parallel gaps matched that of the conventional operation of such gaps.

Exploitation of thermophoresis effect to prevent re-deposition of expelled particulates in laser assisted surface cleaning

Evidence in the improvement of the cleaning efficiency in the case of laser assisted surface decontamination wherein the phenomenon of thermophoresis has been exploited to prevent re-deposition of minute particulates is reported. The thermophoresis effect was made to set in by providing an appropriate temperature gradient in the vicinity of the laser exposed surface. The effectiveness of thermophoresis towards improving the laser assisted cleaning efficiency of polished stainless steel (SS) surface contaminated with copper telluride metal chalcogenide nanoparticles has been studied and compared with that obtained under ambient and dynamic vacuum conditions.

Repetitive operation of switchless transverse flow transversely excited atmosphere CO2 lasers

The enhanced preionisation efficiency of a mutually coupled parallel spark preioniser has been exploited to achieve switchless operation of a transversely excited atmosphere (TEA) CO(2) laser in the conventional transverse gas flow configuration. This made the laser more compatible to repetitive operation and the satisfactory performance of a switchless TEA CO(2) laser of ~8 cc active volume is reported here up to a maximum repetition rate of 100 Hz at a gas replenishment factor of ~2.