CM-20
OPERATION PROCEDURES FOR PHILIPS/FEI CM-20
TRANSMISSION ELECTRON MICROSCOPE
General Comments
Normally the microscope will be left in the power ON (standby ready to operate)
condition; i.e., all circuits will be continuously energized and the microscope will be under full
vacuum (MAIN, VACUUM, HIGH TENSION lamps on the right control panel are all lit if the
PANEL DIM is pressed). If it is not in this condition do not operate the microscope. Seek help
from authorized personnel.
If the microscope is in standby ready condition, proceed with the following abbreviated
procedures for high voltage application and alignment before beginning any observation. If the
microscope is not properly aligned, good results will not be obtained.
I. Start-Up (This procedure is when the microscope starts from cold)
(1) Run the cooling water (for vacuum and lens systems).
(2) Turn on the main power line (in mechanical room, behind the microscope room).
(3) Press the ON power switch on MICROSCOPE. The microscope will go through a series
of self check by the computer program. It will automatically turn on VACUUM
SYSTEM, and reach to the high vacuum state as indicated by the UHV and HI VAC
lights.
II. Specimen Exchange
(i) Specimen Unloading:
(1) Make sure specimen position is at center, i.e., SHIFT (right at 0, left at 10), TILT
indicator at 0 and 11 (HOLDER/azimuth) and tilt drive is engaged.
(2) From holding position (B): Pull out the specimen holder gently until it no longer moves
and then turn it clockwise about 180 degree until it stops (A position, make sure it no
longer turns, the indicator box face down).
(3) Gently extract the holder from the airlock.
(4) Place the specimen holder onto a proper sample holder stand/support for specimen
loading/unloading.
(ii) Specimen Loading:
(1) Set specimen onto suitable specimen holder. USE GLOVES! Caution: No direct
contact of your hand with a specimen holder and any other part which will be placed
inside the microscope.
WAC, 09/27/02
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(2) Hold the specimen holder with the airlock-opening pin up. Carefully insert the specimen
holder into the airlock entry and slide it in until stop. At this point, pre-pumping of the
airlock commences as indicated by illumination of the red airlock indicator light.
(3) After hearing a click sound, grape the specimen holder and turn clockwise, the specimen
holder will slide into a groove in the airlock by vacuum.
(4) Wait until the airlock indicator light extinguishes, then rotate the holder counter
clockwise until it reaches a position where it will slide inwards. The holder is pulled
strongly inward by the pressure differential, which may damage the sapphire pivot at the
holder tip by colliding with the thrust rod of the specimen control. We recommend to
keep your hand on the specimen holder handle and keep it moving slowly inward.
(5) Turn counterclockwise a few degrees and insert the specimen holder to the beam path (C
position).
III Routine Alignment (See Alignment Procedures for CM-20 TEM)
IV. Shut Down
(1) Set Magnification at 100 kx.
(2) Remove objective aperture and SAD apertures (levers to the right).
(3) Press MODES on TEM bright field page.
(4) Press CONFIGURATION on mode selection page.
(5) Turn the FILAMENT knob counterclockwise slowly (with 5-10 seconds between each
setting/click) until the number after ACTUAL on the configuration page is 0.
(6) Set sample stage to center position (right = 0, left = 10).
(7) Make sure goniometer is locked and back to 0 tilt position (tilt = 0, azimuth = 11).
(8) Carefully remove specimen holder out of the microscope column.
(9) Remove your specimen and insert the specimen holder into the microscope (keep in high
vacuum).
(10) Cover viewing ports.
(A) If no pictures taken:
(1) Press READY twice to go back start-up page.
(2) Pull the PANEL DIM knob and leave the microscope for the next user (do not turn off
the high voltage).
(3) Fill out TEM log book.
(4) Clean the desk and keep the microscope room clean.
(B) If Pictures taken:
(1)
Press VACUUM on TEM bright field page.
(2) Press CAM AIR on vacuum status page to leak air (nitrogen) into the camera.
(3) Wait for 3 minutes and then replace the camera box in the microscope with the camera
box in the pre-evacuation chamber (desiccator outside the dark room).
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(4) Make sure the camera cover is correctly placed, and then press CAM AIR again to pump
the camera chamber. You should be able to hear the mechanical pump starting. Pull on
the camera lid to ensure the vacuum is pulling.
(5) Press READY, then TEM CAMERA, and CAM INIT.
(6) Press RESET to reset film number (to 36), and press READY.
(7) Press MODES and then READY to go to start-up page.
(8) Develop your films (negatives). Be careful not to contaminate any chemicals onto the
unexposed films when you changing films in the dark room. Make sure there are 36
films in the unexposed camera box.
(9) On the start-up page, if the VACUUM STATUS says READY, push HIGH TENSION
button and the green LED should light. If the VACUUM STATUS says START-UP (i.e.,
the microscope column not reach to high vacuum yet), wait for it to say READY and then
push the HIGH TENSION button.
(10) Pull the PANEL DIM knob and leave the microscope for the next user.
(11) Fill out TEM log book.
(12) Make sure the microscope room and working areas (TEM consol, table/bench, and put
chair into proper position…etc.) are clean before you leave.
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ROUTINE ALIGNMENT PROCEDURES FOR PHILIPS CM-20 TEM
The following protocol is not intended to be specific. It is intended to be used as a mean
to refresh one’s memory in carry out step by step procedures which are necessary to obtain
reasonably good results with the transmission electron microscopes. More specific information
can be obtained from the instruction manual from the Microscopist in Charge or the Center
Director. Please do not hesitate to ask about anything you do not understand.
I. Before Starting, Verify:
(1) Check log book. Enter your name in the log book before any action on the microscope.
Note cumulative hours on filament and past difficulties. Note: You must have your name
on the reservation.
(2) Push PANEL DIM and turn DATA DIM knobs in to turn on display.
(3) Ascertain vacuum in good condition by press VACUUM on the screen. IGP<25. UHV,
HIVAC (under vacuum system) are lit.
(4) Fill cold trap with liquid nitrogen (LN2 cylinder located outside the TEM room).
(5) All apertures out (levers should be to the right) except condenser aperture.
(6) Tilt indicator is at 0
(7) Specimen holder position at 0 (right) and 10 (left) position.
II. To Apply High Voltage:
Normally the microscope is in standby condition with HV on. Check high tension LED
(green light). If it is on, go to step III. If it is not, you need to turn on the voltage.
(1) Press MODES and TEM to enter the TEM bright field page.
(2) Press PARAMETERS on the TEM bright field page.
(3) Select Emission 1 (or the default number) and High Tension 20 kV using soft keys. If the
microscope has been used, then set at 200 kV (see below),
(4) Make sure IGP<25 on vacuum page.
(5) The following procedures (step 5 through 8) are applied after changing a new filament or
the accelerating voltage has been off for some time (a few days). If the microscope has
been continuously used, then make sure the setting is at 200 and push HIGH TENSION to
turn on the accelerating voltage. Go to step III (to apply filament current) after the HT
has stabilized (i.e., Emission meter is stable).
o
(TILT) and 11o (HOLDER) degree, respectively.
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