Changes

==Updates for June==

==Updates for June==

*Based on the observed beam characteristics and advice from neighboring laser groups, it was decided that the main gas cavity may be dirty therefore preventing passivation of the system. After an exciplex molecule has emitted a photon it returns to its stable state of fluorine and argon, before it can be used for lasing again it requires a rest period. A flow of gas from a circulating fan supplies fresh gas to the lasing window to compensate for this lag time. As the gas is cycled it passes through a series of heat exchangers and a particle filtration system. Each of these are possible sites for corrosion build up which would contaminate the fluorine gas during the cycling process. The figure bellow illustrates the typical gas cavity setup within an excimer laser.

*Based on the observed beam characteristics and advice from neighboring laser groups, it was decided that the main gas cavity may be dirty therefore preventing passivation of the system. After an exciplex molecule has emitted a photon it returns to its stable state of fluorine and argon, before it can be used for lasing again it requires a rest period. A flow of gas from a circulating fan supplies fresh gas to the lasing window to compensate for this lag time. As the gas is cycled it passes through a series of heat exchangers and a particle filtration system. Each of these are possible sites for corrosion build up which would contaminate the fluorine gas during the cycling process. The figure bellow illustrates the typical gas cavity setup within an excimer laser.

[[Image:Gas_Cavity.png|center|thumb|500px|]]

[[Image:Gas_Cavity.png|center|thumb|400px|]]

The plan is to take the laser completely apart and remove the gas cavity for cleaning. Depending on the amount of debris we see, we will be able to determine if this was a likely cause of poor passivation.

The plan is to take the laser completely apart and remove the gas cavity for cleaning. Depending on the amount of debris we see, we will be able to determine if this was a likely cause of poor passivation.

*After removing the electronics and the lasing tube it was clear that there was a large amount of green/yellow corrosion within the gas cavity. Once we saw this we decided to remove the entire gas assembly and under go a complete cleaning of the gas recirculation system. Below are a series of pictures showing the pieces before and after the cleaning which was done with ethanol sandpaper and Kim wipes with a final propanol rinse.

==Passivation for ArF==

==Passivation for ArF==