Rules of use
- Only researchers with TEM experience are allowed to use electron microscopes of the centre.
- Other persons may be trained by members of the staff to operate the microscope themselves.
- When damage occurs as the result of improper use of the microscope, the user will be held responsible for the costs to repair the damage. When in doubt about the condition of the microscope, the staff of the centre must be consulted.
- When leaving the TEM unattended the access door must be locked.
Materials to be studied
- Before TEM investigations are started, the plans for TEM investigations are to be discussed with the staff of the centre.
- When magnetic material is to be studied the staff of the centre must be consulted first.
- When loss of magnetic material in the microscope occurs, the microscope must be opened to remove this material. The costs, between 2500 and 5000 Euro must be paid by the user.
- If specimens can be contaminating in the TEM, this must be discussed with the staff of the centre before insertion into the microscope.
TEM session, reservations
- Three TEM sessions exist on one day, for which reservations can be made:
- morning session: 9 am – 1 pm
- afternoon session: 1 pm – 5 pm
- evening session: 5 pm – 10 pm, the building is closed 10:30 pm – 7 am (9 am during weekend)
Sessions can be extended without overlap with other sessions and in mutual arrangement with other users if necessary. At least 4 hours should be used when a reservation is made. Suitable specimens in sufficient numbers must be prepared beforehand to guarantee full use of the microscope.
- In principle each user can make a reservation for one session a week. More reservations are allowed if possible. No rights can be claimed by way of reservations. The staff can always change reservations for emergency cases like maintenance of the microscope and other cases.
Starting a TEM session at the CM30T
- The high tension should be on before you start, if not consult the previous user. When in doubt a member of the staff should be consulted.
- The sample holder must be checked before use: the sapphire tip must be clean and undamaged (use the light microscope); all other components should be OK, if not, alert a member of the staff.
- Before inserting a specimen holder into the TEM, the vacuum must be better than IGP=25, and usuallythe liquid nitrogen cold finger must be cooled for at least 10 minutes.
- When inserting the holder into the TEM, take care not to let go of the holder: shock will damage the sapphire tip.
- When the vacuum is better than IGP=20 and the specimen holder is inserted, the filament current must be increased slowly (10 sec per step).
Starting a TEM session at the CM30UT-FEG
- The sample holder must be checked before use. Before inserting a double tilt holder into the TEM the wire must be connected to the microscope, the correct holder must be chosen on the menu, and the vacuum must be better than IGP=25, respectively. If a single tilt holder is used, do not attach the cable.
- Before opening the FEG valve, the specimen holder must be moved to extreme positions (at least 500 Î¼m) and back until leakage occurs.
- The high tension should be on before you start, if not consult a member of the staff. The FEG extraction voltage can be increased using the Tietz computer if the vacuum of the FEG is OK.
- The FEG valve can be opened slowly when the vacuum is better than IGP=25.
Operation of the TEM
- A TEM is a subtle instrument which must be operated with care. Never apply extra force during an operation if an unusual mechanical resistance is experienced.
- When in doubt before a specific TEM operation is performed, a member of the staff should be consulted. Never try actions of which the result is uncertain.
- Never leave the CM30UT-FEG without closing the FEG-valve.
- Always warn a staff member when unusual things happen or are found at the microscope.
Ending a TEM session
- The microscopist must leave the microscope in a good condition for the next user:
- Photographic plates should be changed when more than 6 plates have been used. Before pressing “cam air” it must be checked that: filament current has been turned off, high tension is turned off, the nitrogen pressure (meter at the wall) is smaller than 0.3 atm and the valve is open. When the plates have been changed, the plate number must be reset to 36, and the valve at the wall must be closed.
- The high tension must be turned on again when the vacuum of the microscope has recovered after changing plates.
- When nobody will use the TEM the same day after your session, the cold finger of the CM30T (not the UT) must be warmed up before changing plates. Before warming up the cold finger, HT and filament must be turned off. During warming up, IGP must be turned off when it rises above 32. It should be turned on again when P3 has lowered to 55. When the vacuum is OK (vacuum ready and V6 is closed), plates can be removed. If vacuum is OK again when fresh plates have been inserted, HT must be turned on (300 kV) before you leave.
- The microscope is to be left aligned at 300 kV.
- The magnification must be left at a value higher than 10000 in order to leave the objective lens activated and stabilised.
- The logbook must be filled in. The specimen holder must be checked before and after use. If OK, the appropriate boxes in the logbook must be checked, if not, the staff of the centre must be alerted.
- The alignment of the microscope must be saved after each session, using the appropriate program.
- The holder must be removed from the microscope gently: if too much force is applied, the vacuum system will fail.
- The holders must be stored in the appropriate place with the closing ring and anti-twist ring placed into the holder.
- At the CM30UT, if it is the last session of the day: the filling ring and clamp must be re-inserted into the holder, and the holder must be inserted back into the microscope. If it is not the last session of the day, the holder can be left on the table.
Reservations for a TEM session
- Reservations for a TEM can be made on the internet.
- In principle only one session a week can be reserved during day time. If more than one session is reserved, the staff can change reservations (after consultation if possible).
- No rights can be claimed by way of reservations. The staff can always change reservations for emergency cases like maintenance of the microscope and other cases.
Contact persons in cases of problems with the microscope
In case of doubt about the operation of the microscope: never do things you don’t know, ask some one who does.
For information about Safety & Health regulations and also for information about working in the laboratories outside office hours we like to refer to the website of the department Safety, Health and Environment of the Faculty of Applied Sciences, please follow this link