Set-up for a transversely excited laser operating at atmospheric pressure

A high power pulsed laser set-up comprising a laser-tube and a generator, screened at least transversely from the environment, by a housing that forms a conductor for one of the electrodes of the tube.

BACKGROUND OF THE INVENTION 
The invention relates to an improvement in the construction of a high power 
pulsed laser set-up, comprising a laser tube with substantially uniform 
field electrodes, with trigger means, with a generator connected to the 
said electrodes and with a resistor in one of the conductors to the 
electrodes. 
Such a set-up is known in the art. In this set-up known in the art the 
laser tube and the generator are independent units, which are 
interconnected by conductors. It has been found that such a set-up sets 
limits to both input energy per volume-unit of the tube and to the 
efficiency with which this energy is converted into pulses in the tube. 
SUMMARY OF THE INVENTION 
The object of the invention is to raise these limits and, therefore, it is 
characterized in that, at least transversely, the generator and the laser 
tube together are screened from the environment by a housing that forms a 
conductor for one of the electrodes of the tube. 
It was found that by applying the invention, the input energy and the 
efficiency of conversion could be raised. 
The invention yields to a very fast circuit, because the circuit has a very 
low self-induction with respect to the circuits known in the art. This 
might be an explanation for the improvement. 
In a specific embodiment of the set-up according to the invention the tube 
is symmetrically attached on top of the generator. As a result of this 
set-up a substantially induction-free room has been created in the housing 
and so near and in the tube, as a result of which the influence on the gas 
in the tube of the current through the conductors has been greatly reduced 
.

In FIG. 1 cavity resonator 1 of laser tube 2 is provided with electrodes 3, 
4 with Rogowski profiles. Via conductors 5, 6 electrodes 3, 4 are 
connected with a generator unit 7. 
It has been found that with a set-up as is shown in FIG. 1, limits have 
been set to the input energy per liter of cavity resonator, which 
manifests itself in a maximum discharge height X, which is approximately 
6.5 cm. 
By designing, as shown in FIG. 2, conductor 6 as a housing and as a result 
with a very low self-induction, in combination with a very short conductor 
5, a very fast circuit was realized, which was found to be a condition for 
a rise in the values of the above limits. 
This effect may be furthermore increased by applying a generator 7 with a 
higher output voltage at a constant output energy. Such a generator 7 has 
lower capacities and as a result a smaller RC-constant. This RC-constant 
can be adapted to cavity resonator 1 with the aid of a copper sulphate 
resistor 8 in conductor 5. 
In the embodiment of the invention as has been shown in FIG. 2 
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generator 7 is: a marx generator 
peak voltage 240 kV 
energy 2,400 Joules 
resistor 8 is: 20 Ohms 
laser tube 2: diameter y' 15 cm 
cavity resonator 1 l .times. b .times. h 
100 .times. 50 .times. 10 cm.sup.3 
discharge length: 60 cm 
discharge breadth: 
10 cm 
discharge height X = 
10 cm 
screen 6 Cu thickness 0.1 cm 
length 1' 100 cm 
breadth b' 70 cm 
height h' 120 cm 
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