CM200 FEG usage: GUN: FEG Register Program (Windows) can save gun parameters and alignments useful for different setups (electron diff and imaging) FEG Registers on microscope can save gun parameters in 6 registers To turn up extraction voltage either turn up manually or press "Preset Extractor" which goes up to 3.8kV automatically, must advance more manually extraction voltage of 4.1 kV used for tests Turn down to 180kV overnight "Free Control" on gun kV page and turn focus know to get 180 kV - use step size for control Energy spread of the beam increases with extraction voltage should have been measured for our EM and available in Mahwah During alignment, beam should look triangular in spot 1 due to condensor astigmatism Goal during alignment is to center beam in spot Lenses: EXP button normalizes lenses when screen is lowered RST puts preset currents in lenses Coils: pivot Point Alignment: first do beam coils alignments by hitting ALIGN button second to image coils by going into Service Calibrate must go through whole procedure hitting "ready" after each step repeat one time perhaps necessary to do this with EBID board switched either on or off, depending on application Spot Scan: put beam on small screen and read exposure time adjust size of spot and compare with small screen and multiply by ratio of real spot area/small screen area Goiniometer: tilt axis => x axis and 144 deg relative to x = tilt axis but can change low-dose axes for beam/image shift (search mode) under "measuring", Measuring Stereo, axis calib use mag for imaging center particle shift image along desired axis (tilt axis = x watch numbers for true x axis) use beam shift to put particle back to center Maybe best to leave uncalibrated and use 144 deg for tilt axis Plate jamb: no FEG restart: close gun valve go to camera page and press "reset" unplug electronics camera air remove camera chamber window remove plate from sled close up and continue replug electronics alternative involving FEG restart: go to STANDBY remove plate restart FEG Water Temperature: final goal is to get temperature of holder inside EM same as temperature while outside EM To go for simultaneous measurement of two temperatures: tape themocouple to holder tip and compare resulting temperatures insert holder and measure temperature hang thermocouple near column and compare adjust water temperature as column will take a long time to equilibrate with changes in room air 23.25 deg taped to Oxford holder (Oxford reads 21.6) 23.7 deg taped to left hand side of column at stage level 23.27 deg hanging in air near column 25.65 deg taped inside goiniometer air lock (warmer due to motors) General: "reset" button will clear alignment values if in alignment page all alignments lost only when do RAM INITIATE or dowload new program to do RAM initiate service calibrate select RAM initiate push RESTART button immediately For PANIC situation: DO NOT push RESTART button (will let small amount of air into column to help start) Go to STANDBY Then push ON - which will restart computer but preserve vacuum Low Mag Resolution test: below about 115kx, the grain size of the film becomes important use 4489 film to do high resol tests at 66kx and underdevelop for best results Gatan MSC Camera 14 bit data from camera Turbo mode ~10/sec is 8 bit Detector setup on microscope should be in TV-SYST position Gain Reference every day for best data - especially if camera turned off Retract camera when not in use to prevent dirt falling on it Camera can be left cold to maintain stable temperature, but should be heated up every 2 weeks or so to evaporate contamination from surface of CCD Get Temp Script will get camera temperature should leave camera on if plan to use it as temperature is rather unstable and takes a long time to equilibrate and tempreature determines level of dark noise HIGH resolution package in Packages folder - Remote control for MaC from Philips will allow Gatan Scripts for autotuning from Grimm of Baumeister's group Global Info -> tags has paramters for scripts which can be changes (e.g. drift measurement parameters) Global Info -> tags -> MSC: camera mag factor was set at 1.4271122 Hit ESC to stop image acquisition immediately (space after next image) Contact Paul Mooney about uncharging CCD after diffraction idea is that a few elements get charged up and need to put intense uniform beam across whole CCD to drain away charge Ivo's Spot Scan program Delay on Display Functions of 5 msec causes better image for 4-spot mode - due to historesis of coils during fast movement Adjust fast/slow axis with slide bars - different sensitivities depending on where you push - arrows is finest, scroll bar next Shutter automatically openned upon start of scan - even when "auto Shutter" disabled on setup page - this allows shutter to be closed manually before scan Sorcus board: module 3: beam shift x and y module 2: image shift x and y module 1: shutter and obj lens control (focus) Oxford Cryo-holder