CS202162B1 - Discharge lamp for the gas laser with inner gas reverse flow - Google Patents

Abstract

The discharge tube, for continuously-operated gas lasers, has the gas flow in the return channel increased and the risk of breakdown in this channel is reduced by providing the tube with at least one circular gap around its internal surface interrupted by a breakdown-preventing block. The main advantage of this arrangement lies in the gas being free to flow over the relatively cool outer wall. The circular gap between the segments and the enclosing quartz tube presents a large cross-section to the returning gas. Breakdown is avoided by placing the discharge and return channels relatively far apart.

Description

BACKGROUND OF THE INVENTION The present invention relates to a gas laser discharge lamp having the possibility for a backward flow of gas.

The invention is particularly intended for use in the design of continuously operating ion lasers. In such lasers, a pressure drop and a density along the discharge channel result from a gas discharge. The pressure gradient generated along the discharge channel as a result of the so-called gas pumping must be counteracted by appropriate measures.

It is known that external gas return ducts adversely affect production technology and the possibility of replacement in the event of failures of mass-produced gas lasers. To prevent unwanted inflammation, they had to be designed as helical tubes, see for example DE-AS 1,219.604. Therefore, gas return ducts extending inside the lamp are used unless extremely high powers require other solutions.

Known laser ion lamps, which are composed of conductive disks (segments), which are contained in a non-conductive, air-tightly sealed package, for example of quartz, comprise a gas return channel consisting of openings in the individual conductive disks. These openings are partially offset from each other to reduce the risk of ignition (IEEE Joum. Quantum Electronic, QE-3, 1967, pp. 66-72). For this reason, the holes have a very small diameter.

The number of return ducts in special embodiments has increased to such an extent that the conductive disc has taken the form of a sieve, see FIG. U.S. Patent No. 3,619,810. However, these measures substantially reduce the required high flow rate of the gas return ducts thus formed and impair its efficiency. Furthermore, the action of the hot walls of the gas return ducts increases the viscosity of the gas, which additionally adversely affects the conductivity of the gas stream.

The purpose of the invention is to substantially simplify the technology in the serial production of laser tubes with a discharge channel and an internal gas return channel.

SUMMARY OF THE INVENTION It is an object of the present invention to increase the conductivity in the high-current ion backflow gas channel while attaining ignition strength by making the return channel as flat as possible.

This object is achieved in the lamp according to the invention by providing an annular gap at the inner wall of the quartz tube, which is interrupted at least in one place by the anti-ignition plug segments.

The great advantage of this gas return duct arrangement lies above all in the. that the gas can flow along the relatively cold outer wall. A further advantage results from the fact that the annular gap arranged between the segments and the quartz tube has a return. a gas flow of a large cross section, which is either interrupted at only one or a few places by an ignition lock and that there is a risk of ignition. This is achieved by the fact that the discharge channel and the gas return channel are relatively far apart.

The essence of the invention will be. in another . of the text will be explained in more detail by way of an exemplary embodiment, shown in the drawing, where:

1 shows a longitudinal section. a quartz tube according to the invention;

na .obr. Fig. 2 shows a segment of the discharge channel, and Figs. 3 and 4 show two segments representing the closure against ignition.

FIG. 1 shows a quartz tube 1 which is part of a lamp which for the sake of simplicity. not shown in more detail. This quartz tube 1 forms the outer casing for the discharge channel formed of the individual segments 2. The segments 2 have the shape shown. in the front. 2. discharge channel realization and. . apertures 4 adapted to align the individual segments 2 at the outer edge. The channel segments 2 have. on its circumference, the protrusions 5 which abut the quartz tube 1. The two segments 6 and 7 (shown in FIGS. 3 and 4) and which form a closure against ignition differ from said shape. The segment 6 comprises a row of holes 8 on a circle near the edge, the adjacent segment 7 having these holes on a circle whose radius differs from the circle of segment 6. This creates an effective ignition closure, as can be seen in particular in FIG. optimal return line for gas.

Claims (1)

Gas discharge lamp with internal gas return, characterized in that an annular gap is provided at the inner wall of the quartz tube (1). interrupted in at least one point by the closure. anti-ignition segments (6, 7).