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| groups:mg:experiment:vacuum [2017/10/24 06:39] – wfriesen | groups:mg:experiment:vacuum [2018/11/01 10:25] (current) – [Oil change of the pre-vacuum pump] fim | ||
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| | Switch off the ion getter pump: \\ According to Manual: Select LOCAL mode, briefly pressing the “MODE” key until LOCAL is shown on the display. Hold down the HV ON/OFF button while pressing the HV-x button where x is the number of the channel to be switched on/off. In case this does not work, or for any other issues, turning off the whole unit also works. \\ Ionengetterpumpe ausschalten|{{ : | | Switch off the ion getter pump: \\ According to Manual: Select LOCAL mode, briefly pressing the “MODE” key until LOCAL is shown on the display. Hold down the HV ON/OFF button while pressing the HV-x button where x is the number of the channel to be switched on/off. In case this does not work, or for any other issues, turning off the whole unit also works. \\ Ionengetterpumpe ausschalten|{{ : | ||
| | Close valve (under the table) between the main chamber and the big turbo pump: \\ Hochvakuumventil zwischen Hauptkammer und großer Turbopumpe schließen (unter dem Tisch)|{{ : | | Close valve (under the table) between the main chamber and the big turbo pump: \\ Hochvakuumventil zwischen Hauptkammer und großer Turbopumpe schließen (unter dem Tisch)|{{ : | ||
| - | |Close both pneumatic valve between turbopump and prevacuum by pressing | + | |Close both pneumatic valve between turbopump and prevacuum by taking out the plug from the wall near „Notaus“ at the door (it's connected to the orange switch). This closes both the pneumatic valves between the turbo pumps of the oven chamber and science chamber and their respective pre-vacuum. Make sure both valves are closed. The valve for the science chamber turbo pump is under the table. \\ Beide pneumatischen Magnetventile zwischen den Turbopumpen und dem Vorvakuum schließen, |
| | Close the (yellow) hand valve at the small turbo pump: \\ Handventil (gelb) an der Vorvakuumseite der kleinen Turbopumpe schließen|{{ : | | Close the (yellow) hand valve at the small turbo pump: \\ Handventil (gelb) an der Vorvakuumseite der kleinen Turbopumpe schließen|{{ : | ||
| | Switch off cold cathode measuring instrument: \\ Kaltkathoden-Messgerät (Hauptkammer) ausschalten (nicht für Druck > 10-3) mbar geeignet|{{ : | | Switch off cold cathode measuring instrument: \\ Kaltkathoden-Messgerät (Hauptkammer) ausschalten (nicht für Druck > 10-3) mbar geeignet|{{ : | ||
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| * 2015/12/17 Changed: Lattice Viewports from vacom, Zeeman Viewport, PMT viewport | * 2015/12/17 Changed: Lattice Viewports from vacom, Zeeman Viewport, PMT viewport | ||
| * 2015/12/23 Changed: Lattice viewports are now indium sealed again | * 2015/12/23 Changed: Lattice viewports are now indium sealed again | ||
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| + | ===== How to evacuate the vacuum chamber ===== | ||
| + | * Beforeyou close the vaccum chamber, disconnect the protective gas and the cable of the vent valve, to avoid overpressure in the chamber. | ||
| + | * Chack if all Viewports are assembled. | ||
| + | * Open (only!) the pneumatic magnetic valve of the small Turbo pump. Disconnect the plug for the pneumatic magnetic valve of the big turbo pump at the power extension board, which is located on top of the flowbox. After doing so plug in the yellow plug near the door and press ' | ||
| + | * Gently open the yellow hand valve at the small Turbo pump. This will pump down the chamber to the pre-vacuum level. Opening the valve will worse the pre-vacuum. Don't let the needle hit the end of the scale at the measuring device for the pre-vacuum. | ||
| + | * Wait until the pre-vacuum reach <10^1 mbar. | ||
| + | * Open the pneumatic magnetic valve at the big Turbo pump. | ||
| + | * Turn on both Turbo pumps and wait untill both have reached nominal speed. | ||
| + | * Open the valve under the table of the big Turbo pump by connecting the plug at the power extension board. | ||
| + | * Switch on the cold-cathod measuring device when the pressure in the main chamber is below 10^-3 mbar. | ||
| + | * Turn on the IGP when the pressure has reached 10^-6 mbar. Initially this will cause the pressure to rise again. | ||
| + | |||
| + | ===== How to refill magnesium in the oven ===== | ||
| + | * For opening the oven, at least two people are required. | ||
| + | * The Oven is attached to the chamber with a CF 63 flange. So keep a fresh CF63 copper gasket ready for replacement. | ||
| + | * Pump down the vacuuum chamber following the same procedure as above. | ||
| + | * Open the CF 63 flange connecting oven to the vacuum chamber. | ||
| + | * Oven is extended lengthwise into the vacuum chamber. Gently pull out the tube without hitting the walls of the chamber. | ||
| + | * The oven nozzle is connected in the end of the tube with a nut. Open this nut to take out the nozzle. | ||
| + | * Clean the nozzle as well as the inside of the oven with acetone. Make sure that acetone is fresh and does not contain any water. | ||
| + | * Also clean any other tools (spoons etc) that you will use to pour magnesium flakes into the oven. | ||
| + | * Now fill the oven to the top and again fix back the nut with the nozzle on it. | ||
| + | * Reconnect the oven flange to the vacuum chamber with a fresh copper gasket. Make sure that the vent gas is turned off before fixing the screws to avoid overpressure in the chamber. | ||
| + | |||
| + | {{: | ||
| + | |||
| ===== Heating the pumps (usefull for low 10^-9 pressures and below and after opening the vacuum) ===== | ===== Heating the pumps (usefull for low 10^-9 pressures and below and after opening the vacuum) ===== | ||
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| Either locally heat the window or the flange, where a window might be attached to, to like 160-180 °C. This will make the indium to become liquid (T_liquid ~ 156 °C). Now you can press slightly either from the side (if attached to the chamber) or from the other side of the flange. My suggestion is to use an oven to heat flanges. | Either locally heat the window or the flange, where a window might be attached to, to like 160-180 °C. This will make the indium to become liquid (T_liquid ~ 156 °C). Now you can press slightly either from the side (if attached to the chamber) or from the other side of the flange. My suggestion is to use an oven to heat flanges. | ||
| When still liquid or heated, it is also easier to remove indium residuals from the flange. Be careful not to scratch the window or sealing surface, because then they will become unusable for new sealings. | When still liquid or heated, it is also easier to remove indium residuals from the flange. Be careful not to scratch the window or sealing surface, because then they will become unusable for new sealings. | ||
| - | |||
| - | ===== How to evacuate the vacuum chamber ===== | ||
| - | * Beforeyou close the vaccum chamber, disconnect the protective gas and the cable of the vent valve, to avoid overpressure in the chamber. | ||
| - | * Chack if all Viewports are assembled. | ||
| - | * Open (only!) the pneumatic magnetic valve at the small Turbo pump. | ||
| - | * Gently open the yellow hand valve at the small Turbo pump. This will pump down the chamber to the pre-vacuum level. Opening the valve will worse the pre-vacuum. Don't let the needle hit the end of the scale at the measuring device for the pre-vacuum. This process can easily take two hours or more, until the yellow hand valve is completely opened. | ||
| - | * Wait until the pre-vacuum reach <10^1 mbar. | ||
| - | * Open the pneumatic magnetic valve at the big Turbo pump. | ||
| - | * Turn on both Turbo pumps and wait untill both have reached nominal speed. | ||
| - | * Open the valve under the table at the big Turbo pump. | ||
| - | * Switch on the cold-cathod measuring device when the pressure in the main chamber is below 10^-3 mbar. | ||
| - | * Turn on the IGP when the pressure has reached 10^-6 mbar. Initially this will cause the pressure to rise again. | ||
| ===== Datenblätter ===== | ===== Datenblätter ===== | ||
| Line 133: | Line 148: | ||
| *Turbomolekularpumpe TMU 260: {{: | *Turbomolekularpumpe TMU 260: {{: | ||
| #*In Betrieb seit XY | #*In Betrieb seit XY | ||
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| + | ====== Oil change of the pre-vacuum pump ====== | ||
| + | |||
| + | The oil has to be changed **every third year** approximately. | ||
| + | |||
| + | - First, close the big yellow vent at the source chamber. Second, close the pneumatik vents via the knob at the orange power outlet (close to the door) and check if both are really closed. | ||
| + | - CLose the black vent of the pump which is placed close to the on/off switch. | ||
| + | - Open the drain screw (No. 8 in manul) labed as " | ||
| + | - Open the vents once the preassure at the pump is the same as at the source chamber. | ||
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| + | Manual: {{ : | ||
| + | |||
| + | Last changes: nov 2018 | ||
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