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| pld:start [2015/01/29 14:45] – bethany | pld:start [2015/04/22 14:00] – james |
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| //Thermionics chamber//: The Thermionics chamber is set up so that in event of a power failure, the valves between the roughing and turbo pumps will remain closed and the pumps will not turn back on when power is restored. However, the gate valve to the main chamber will be automatically closed, which will prevent the chamber from venting to atmospheric pressure immediately. With the gate valve closed, the pressure should stay in the 10<sup>-7</sup> Torr range and very slowly increase until the system is reset. | //Thermionics chamber//: The Thermionics chamber is set up so that in event of a power failure, the valves between the roughing and turbo pumps will remain closed and the pumps will not turn back on when power is restored. However, the gate valve to the main chamber will be automatically closed, which will prevent the chamber from venting to atmospheric pressure immediately. With the gate valve closed, the pressure should stay in the 10<sup>-7</sup> Torr range and very slowly increase until the system is reset. |
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| If you discover that the power has gone out, make sure that the gate valve has closed (by the red indicator light if the power has been restored, or the white spot on the indicator beneath the gate valve motor is on closed). If the valve is closed, you can use {{:pld:pldthermionicsreset2014.pdf|these instructions}} to restore the system. If the pressure is higher than 10<sup>-3</sup> or if the gate valve does not appear to have closed, then follow the Pump Down Procedures in the instructions (toggle switch up on silver panel, reset buttons on black panels, wait for the pressure to drop below 10<sup>-3</sup> Torr range, then restart Turbo Pumps). Here is a schematic for reference.{{:pld:control_tower.gif|}} | If you discover that the power has gone out, make sure that the gate valve has closed (by the red indicator light if the power has been restored, or the white spot on the indicator beneath the gate valve motor is on closed). If the valve is closed, you can use {{:pld:pldthermionicsresetinstructions012915.pdf|these instructions}} to restore the system. If the pressure is higher than 10<sup>-3</sup> or if the gate valve does not appear to have closed, then follow the Pump Down Procedures in the instructions (toggle switch up on silver panel, reset buttons on black panels, wait for the pressure to drop below 10<sup>-3</sup> Torr range, then restart Turbo Pumps). Here is a schematic for reference.{{:pld:control_tower.gif|}} |
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| ==== Mirrors ==== | ==== Mirrors ==== |
| The 3 mirrors used in the optical tower are from OptoSigma (part no. 034-0185 and ). These mirrors are made of a borosilicate glass (BK7) and are designed specifically for KrF laser use at 45 degrees incidence. When configured in this way, the reflectance should be > 99%. The mirrors on the lowest two tiers of the optics tower are arranged at this angle of incidence. The mirror on the highest tier of the optics tower is setup such that the angle of incidence is 30 degrees. | The 3 mirrors used in the optical tower are from OptoSigma (part no. [[http://www.optosigma.com/products/optical-components/mirrors/laser-line-mirrors/034-0185|034-0185]] and ). These mirrors are made of a borosilicate glass (BK7) and are designed specifically for KrF laser use at 45 degrees incidence. When configured in this way, the reflectance should be > 99%. The mirrors on the lowest two tiers of the optics tower are arranged at this angle of incidence. The mirror on the highest tier of the optics tower is setup such that the angle of incidence is 30 degrees. |
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| {{:pld:bk7.jpg|thumb}} | {{:pld:bk7.jpg|thumb}} |
| \\==== Lenses ==== | \\ |
| The two focusing lenses (one for each chamber) used are of the plano-convex type, and are made of UV grade fused silica. The lenses used have no coatings, and have different focal lengths. The lens used with the Thermionics chamber is OptoSigma part no. 014-1315. | |
| | ==== Lenses ==== |
| | The two focusing lenses (one for each chamber) used are of the plano-convex type, and are made of UV grade fused silica. The lenses used have no coatings, and have different focal lengths. The lens used with the Thermionics chamber is OptoSigma part no. {{:pld:fused_silica_plano_convex_lenses.pdf|014-1315}}. |
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| ==== Windows ==== | ==== Windows ==== |
| There are many windows on the thermionics chamber. However, there are two UV grade laser windows. Each of these is mounted in a ConFlat flange. Each of the laser windows is made of fused silica, and measuring with the Coherent power meter, have a loss of approximately 10% at 248nm. | There are many windows on the thermionics chamber. However, there are two UV grade laser windows. Each of these is mounted in a ConFlat flange. Each of the laser windows is made of [[http://marketplace.idexop.com/store/SupportDocuments/MaterialProperties.pdf|fused silica]], and measuring with the Coherent power meter, have a loss of approximately 10% at 248nm. |
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| ===== Procedure ===== | ===== Procedure ===== |
| {{:pld:neocera.pld.instructions.pdf|Neocera Chamber}} | {{:pld:neocera.pld.instructions.pdf|Neocera Chamber}} |
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| {{:pld:gas_change_20120606.pdf|Laser Gas Change}} | {{:pld:gas_change_20150416.pdf|Laser Gas Change}} |
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| | {{:pld:PLD_viewing_window_cleaning_20150422.pdf|Chamber Window Cleaning}} |
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| | FIXME |
| | Chamber cleaning procedures |
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| ===== Routine Maintenance ===== | ===== Routine Maintenance ===== |
