JPH0479386A - Ion laser apparatus - Google Patents

Abstract

PURPOSE:To reduce sputter materials causing pollutions and reduce gas exhaustion as well and enable extending the life of a laser tube, by inserting a pair of coils in between an electrode and a Brewster's window part, the coils being the same in number of turns and opposite to each other in direction of generative magnetic field. CONSTITUTION:In a solenoid coil 8 for a shield, a coil 8a of the side of a cathode generates the magnetic field of the same direction as a solenoid coil 7, and a coil 8b of the side of a Brewster's window part generates a field in the opposite direction to the solenoid coil 7. When sputter materials pass the part of the solenoid coil 8 for a shield, they receive the force of the direction of them diverging, and are prevented from entering the Brewster's window part. Also, the solenoid coil 8 for a shield acts in such direction that the magnetic lines of force in the end part of a laser capillary converge more effectively. Therefore, the sputter in the end part of the laser capillary is reduced.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an ion laser device.

[Conventional technology]

FIG. 3 is a schematic diagram of a conventional ion laser device. A conventional ion laser device consists of a laser tube and a cathode (2), which also serves as a thermoelectron supply source, placed on both sides of the laser tube. Ion laser tube 5 consisting of an anode 3 and Brewster section 4
A pair of optical resonator mirrors are arranged opposite to the Brewster section 4 at both ends of the solenoid coil 7 for plasma convergence.
is arranged around the laser thin tube 1.

The solenoid coil 7 had the role of converging the plasma, increasing the laser oscillation efficiency, and controlling the sputtering of ions to the wall of the laser tube.

[Problem to be solved by the invention]

Conventional ion laser equipment is equipped with a solenoid coil for plasma convergence, but it is not possible to completely prevent sputtering of the laser tube wall by ions, and the sputtered material moves to the Brewster section and enters the Brewster window. This was one of the major causes of a decrease in laser output. Furthermore, since the magnetic field generated by the solenoid coil tends to spread outward at both ends, the ends of the laser tube are more likely to be spattered, and if the magnetic field is strengthened in an attempt to converge the plasma, the spatter at the ends of the laser tube will be increased. It had the disadvantage of being intense.

[Means to solve the problem]

The sputtered material described above is positively charged because it has been sputtered by positive ions. The charged object moves spirally along the lines of magnetic force, so if a magnetic field is applied in a direction that causes the sputtered material to spread outward, it is possible to block the sputtered material from advancing toward the Brewster portion. Therefore, in the present invention, a pair of coils having the same number of turns and generating magnetic fields in opposite directions is inserted between the electrode and the Brewster section. The coil on the electrode side generates a magnetic field in the same direction as the plasma convergence coil, and the adjacent coil on the Brewster side generates a magnetic field in the opposite direction.

As a result, the lines of magnetic force diverge outward, so that charged sputtered materials can be blocked. Furthermore, since the pair of coils act in a direction to converge the lines of magnetic force at the end of the laser tube, spatter itself can be reduced.

〔Example〕

Next, the present invention will be described in more detail with reference to the accompanying drawings, but what is shown below is only one embodiment of the present invention and does not limit the technical scope of the present invention in any way.

FIG. 1 is a schematic diagram of an ion laser device according to the present invention. The ion laser device consists of an ion laser tube 1.5 consisting of a laser thin tube 1, a cathode 2 which also serves as a thermoelectron supply source, an anode 3, and a Brewster section 4, and a pair of light beams installed to face the ion laser tube 5. A resonance crisis mirror 6, a plasma convergence solenoid coil 7, and a pair of cutoff solenoid coils installed between the cathode 2 and the Brewster section 4 are arranged. In the cutoff solenoid coil 8, the cathode side coil 8a generates a magnetic field in the same direction as the solenoid coil 7, and the Brewster side coil 8b generates a magnetic field in the opposite direction to the solenoid coil 7. The shielding solenoid coil 8 prevents the sputtered material from entering the Brewster section, as it receives a force in the direction of divergence when it passes through the section. Furthermore, the shielding solenoid coil 8 acts in a direction to further converge the direction of the magnetic lines of force at the end of the laser tube, thereby reducing spatter at the end of the laser tube.

FIG. 2 is a schematic diagram of a second embodiment of the present invention. In this embodiment, a pair of shielding solenoid coils 8 are also provided between the anode 3 and the Brewster section 4, and the anode side coil 8c generates a magnetic field in the same direction as the solenoid coil 7, and the Brewster section side coil 8c generates a magnetic field in the same direction as the solenoid coil 7. 8d is solenoid coil 7
It is designed to generate a magnetic field in the opposite direction to the Brewster part, thereby preventing negatively charged sputtered material from entering the Brewster section. The other configurations are the same as in the previous embodiment.

〔Effect of the invention〕

As described in detail above, the present invention installs a shielding solenoid coil consisting of a pair of coils that generate magnetic fields in different directions between the cathode or anode of the ion laser device and the Brewster section, so that the shielding solenoid coil that generates magnetic fields in different directions is installed. This prevents dirt from entering the Brewster window, prevents a drop in laser output, suppresses the spread of magnetic field lines at the end of the laser tube, reduces spatter at the end of the laser tube, and prevents dirt from entering the laser tube. It is possible to reduce the amount of spatter that causes sputtering, and also to reduce gas consumption, thereby extending the life of the laser tube.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an embodiment of the present invention. FIG. 2 is a schematic diagram of an embodiment of the present invention. FIG. 3 is a schematic diagram of an ion laser device according to the prior art. DESCRIPTION OF SYMBOLS 1... Laser thin tube, 2... Cathode, 3... Anode, 4... Brewster part, 5... Ion laser tube, 6... Mirror, 7... Solenoid coil, 8...
...Solenoid coil for shielding.

Claims (1)

[Claims] A pair of optical resonator mirrors are placed opposite to each other at both ends of the ion laser tube, which consists of a laser tube, cathode and anode electrodes placed at both ends, and a Brewster section, and a solenoid for plasma convergence is placed around the laser tube. In an ion laser device in which a coil is installed, a pair of magnetic fields having the same number of turns and generating magnetic fields in opposite directions is installed between one electrode and the Brewster section, or between both electrodes and the Brewster section. An ion laser device characterized in that a shielding solenoid coil made of a solenoid coil is provided, and of the pair of solenoid coils, the solenoid coil closer to the electrode generates a magnetic field in the same direction as the solenoid coil for plasma convergence.