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XeCl excimer laser; magnetic pulse compressor; saturable inductor; micro-machining.

Performance characteristics of an excimer laser (XeCl) with single-stage magnetic pulse compression suitable for material processing applications are presented here. The laser incorporates in-built compact gas circulation and gas cooling to ensure fresh gas mixture between the electrodes for repetitive operation. A magnetically coupled tangential blower is used for gas circulation inside the laser chamber for repetitive operation. The exciter consists of C–C energy transfer circuit and thyratron is used as a high-voltage main switch with singlestage magnetic pulse compression (MPC) between thyratron and the laser electrodes. Low inductance of the laser head and uniform and intense pre-ionization are the main features of the electric circuit used in the laser. A 250 ns rise time voltage pulse was compressed to 100 ns duration with a single-stage magnetic pulse compressor using Ni–Zn ferrite cores. The laser can generate about 150 mJ at ∼100 Hz rep-rate reliably from a discharge volumeof 100 cm$^3$. 2D spatial laser beam profile generated is presented here. The profile shows that the laser beam is completely filled with flat-top which is suitable for material processing applications. The SEM image of the microhole generated on copper target is presented here.

N K VARSHNAY¹ A A SINGH¹ N S BENERJI¹

1. Excimer Laser Section, Laser Material Processing Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013, India

Published

16 February 2017

Manuscript received

21 December 2015

Manuscript revised

23 May 2016

Accepted

20 July 2016

Early published

10 January 2017