Abstract. The output characteristics are described of an X-ray preionized discharge pumped XeC1 laser, fed by a low-impedance pulse forming line (PFL), at pressures up to 12 bar. The influence of a multichannel rail gap placed between the PFL and the laser head on the output energy was studied. We found an increase of output energy with increasing pressure up to 8 bar. At higher pressures a saturation behaviour was found. The maximum output energy per unit volume was 6.5 J/1.
PACS: 42.55G, 42.60High-efficiency operation in a self-sustained avalanche discharge XeC1 laser can be achieved when the laser is operated at high buffer gas pressures. This has been shown by Ernst et al. [1] in a corona preionized system for pressures up to 10 bar.When operating at high pressures and large apertures, the use of X-rays for preionizing the gas is advantageous over UV from, for instance, a corona discharge or an array of spark discharges because of the higher mass penetration depth of X-rays. Besides this, gas contamination caused by sparks or a corona discharge does not occur in X-ray preionized systems. This is especially important when the system is operated at a high repetition rate. Special attention should be paid to the construction of the window which separates the X-ray source from the laser chamber at high pressures; this window should be strong enough to withstand high pressures and as thin as possible to let the low energy X-rays penetrate the laser medium fairly unhampered.In order to obtain a highly efficient operation of the laser it is important to keep the inductance of the circuit low so that the current rise time becomes very short and energy can be delivered to the gas medium rapidly. To lower the current rise time a multichannel rail gap is often used. An optimization study was performed for the use of such a gap. Although numerous studies on large aperture X-ray preionized XeC1 lasers were performed at moderate gas pressures (up to about 5 bar) [24] little information exists on XeCI operation at higher pressures. Recently operation up to 10bar in this type of laser with comparable dimensions was described by Steyer and Voges [5]. In their laser system, however, discharge voltage and current, which have an important influence on the output energy, were limited because a thyratron was used for switching the main discharge. In the system described below the main discharge is fed by a waterfilled, low-impedance pulse forming line (PFL). A selftriggered multichannel rail gap (MCRG) could be mounted between the PFL and the laser head. In this way a higher discharge voltage and current could be obtained. For the high pressure regime we found an output behaviour partially different from others [5,6], as will be discussed below.In this paper we describe the successful operation of a high pressure X-ray preionized XeC1 laser. Details of the operation characteristics of the MCRG are given.
