Differences

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--- pld:start [2014/08/05 15:10] – janet
+++ pld:start [2015/04/22 13:54] – james
@@ Line 23: / Line 23: @@
 === Roughing Pump ===
-The main chamber roughing and turbo pumps are manufactured by BOC Edwards.  Like the Alcatel roughing pump, the oil should be changed every 6 months.  However, it is essential that the oil **is not hydrocarbon oil**.  The replacement oil **must be Krytox 1506** or Fomblin 06/6.  The use of Krytox 1506 is preferred since the Fomblin type oils tend to leak and seep through seals in the pump, while the Krytox will not.  Typically, Krytox is sold by mass rather than by volume like most other oils.  To successfully change the oil, 3kg are needed. As of 5/25/2011 Krytox 1506 costs ~$200/kg. 8/2014: Krytox 1506 costs $2,500/gal = $312.50/kg @ 8kg/gal.  We use about 3kg/year.  Krytox 1506 can be obtained about 6x more cheaply by **recycling** our used Krytox - approx $400/gal - from Kurt Lesker (2 gal minimum) or Ideal Gas (1 gal minimum).
+The main chamber roughing and turbo pumps are manufactured by BOC Edwards.  Like the Alcatel roughing pump, the oil on the Edwards roughing pump should be changed every 6 months.  However, it is essential that the oil **is not hydrocarbon oil**.  The replacement oil **must be Krytox 1506** or Fomblin 06/6.  Krytox 1506 is preferred since the Fomblin-type oils tend to leak and seep through seals in the pump, while the Krytox will not.  Typically, Krytox is sold by mass rather than by volume like most other oils.  To successfully change the oil, 3kg are needed. We use about 3kg/year.
+/2014: Ideal Gas sells Krytox 1506 (new) for $200/kg; Lesker sells Krytox 1506 (new) for $2,500/gal = $312.50/kg @ 8kg/gal.
+Krytox 1506 can be obtained about 6x more cheaply by **recycling** our used Krytox - approx $400/gal = - from Kurt Lesker (but must recycle 2 gal minimum) or from Ideal Gas (1 gal minimum).
+/25/2011: Krytox 1506 costs ~$200/kg.
 Do not mix these PFPE oils with hydrocarbon oils; if this happens the pump must be cleaned according to the manual's instructions as these oils are not compatible.  This means that they are not soluble in one another, and the material properties will change across the interface, foaming may occur, and the pump will not be properly lubricated.  Krytox is used because it is highly resistant to attack by oxygen or corrosive process gasses.  **DO NOT EVER USE OXYGEN PROCESS GAS WITH HYDROCARBON OILS!**
@@ Line 38: / Line 44: @@
 FIXME
 =====Power Outages=====
-//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.
+//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.
+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|}}
-If you discover that the power has gone out while the pressure is still fairly low (10<sup>-3</sup> Torr), you can use {{:pld:thermionicsreset.pdf|these instructions}} to pump the system down.  If the pressure is too high, then start the system up normally after restoring power to the pumps and TMP controllers (toggle switch up on silver panel, reset buttons on black panels - check fuses if nothing happens).
-The Edwards roughing pump on the main chamber frequently fails to start.  If this happens, unplug it from the gray power strip and plug it directly into the wall.  Let it run for a few minutes and then plug it back into the power strip and try to turn it on again.
 //Neocera chamber//:
@@ Line 55: / Line 61: @@
 ==== 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.
 {{: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}}.
 ==== 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.
 ===== Procedure =====
@@ Line 69: / Line 77: @@
 {{:pld:neocera.pld.instructions.pdf|Neocera Chamber}}
-{{:pld:gas_change_20120606.pdf|Laser Gas Change}}
+{{:pld:gas_change_20150416.pdf|Laser Gas Change}}
+__**Viewing window cleaning procedures**__
+Use the paste from lambda physik called Vienna chalk, it is actually a white powder. You need to make a slurry, and a few drops of water go a long way.
+When you think that the slurry is too thick, it is just right.  If it is too watery, the abrasive in the slurry will be ineffective at cleaning.
+Change lens tissues often. As the voids in the paper clog, the cleaning efficiency goes way down.
+After you have cleaned a window, there will be water droplets in small voids that are difficult to dry. This will kill the chamber pressure for quite a long time. You can reduce this by rinsing the window with isopropanol, and then blow drying with N2 gas.  Do this 3-4 times, and be thorough.  Ideally, you would bake the window at 120 C for an hour after this treatment, but most windows will not fit in the furnace we have available.
+FIXME
+Chamber cleaning procedures
 ===== Routine Maintenance =====

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