Jeol JEM Responsible personell: Endy ( ) Online booking is compulsory!

Transcription

1 Jeol JEM 1230 Responsible personell: Endy ( ) Online booking is compulsory! After training you will have access to working alone on the instrument. All insertion of samples is done by responsible MIC personell (Endy and Reidar). 1

2 JEOL JEM 1230 Table of content: The control panel page 3 The sample holder page 4 High tension and beam page 5 Simple beam alignment page 8 Focussing your sample page 9 Inserting camera page 11 Taking pictures page 12 How to save your dm3 images page 14 Converting dm3 images to tiff page 15 Turning off the system page 16 2

3 Control board This switch will change the magnification. Bring it to the left to go down in magnification and right to go up. Beam shift is used to align the beam (this is explained later). The wobbler is usefull for adjusting the focus. Focusing knobs: coarse and fine. Control the brightness of you beam. This button is used when acquiring a photo onto the film negative. This is rarely in use. Leave these buttons on (green light) to have a stepwise increase/decrease of the brightness and focus. 3

4 The sample holder The pentaholder will fit 5 samples at a time. MIC personnel will help you insert your samples into the microscope. Remember to fill out the form with the sample positions. Date: Name: Specimen: Once inserted, you can change between samples by turning the middle wheel (arrow). The number which shows up next to the white circle indicated the sample position on the holder. 4

5 Turning on the high tension and the beam 1. Click onto the circle in front of HT, then click onto ON A Ready will appear behind the HT within 10 seconds. 3. Now turn on the beam by clicking first into the circle in front of the beam, the click onto ON The beam will come on within 20 sec. You will notice the beam current rising from 33 to 44 µa. If the beam current does not rise, notify Endy, the filament could be broken. 5. Turn on the power (A) for the gatan camera. Turn on the cooling (B) for better images. Be careful not to «heat» the camera which is the same switch as for cooling. A B 5

6 Specimen position Make sure that the specimen position window is open to orientate yourself on the grid. Use the roller mouse to move the grid around in order to find your samples. You can also move around by clicking inside the speciment position monitor, but be sure to be in «point» mode. Roller mouse. Click onto the arrows to increase the speed. 6

7 Is the beam well aligned? Fluorescent screen Fluorescent sample mirror Beam slightly missaligned Ok alignment It is very simple to align the beam yourself: 1. Focus your beam (make it small) using the brightness knob. 2. Press beam shift on the control board (it should be green). 3. Use the right mouse button to move the beam into position. 4. Press beam shift again (green light comes off). 7

8 Focussing your sample Before focussing your sample, make sure the ocular is in focus for your eyes. When there is light on your sample, look into the ocular and use the black knob on the side to focus the black spot you see inside your field. 8

9 Focussing your sample To focus you sample use the two knobs (coarse and fine) and focus first on the large fluorescent screen. For fine focus, bring down the fluorescent sample mirror and use the oculars. Some people prefer to focus using the wobbler. Press wobbler on the control table and use the two focusing knobs to stop the image from moving. When image is still, you have focus. BUT: remember to turn off the wobbler! To bring down the fluorescent sample mirror, pull down this handle. Focus onto something with a lot of contrast. 9

10 Inserting the camera The Gatan camera has a resolusion of 1024x1024 pixels. The camera is very sensitive, so make sure the current density is under 10 pa/cm2 before inserting the camera! Open the software: DigitalMicrograph. Insert the camera, see other page. 10

11 Taking pictures To insert camera, make sure the current density is benieth 10 pa/cm2. Select camera inserted (you will hear a sound and your image on the fluorescent screen is gone). Select start view and a window with the live image shows up. Auto exposure just makes life a whole lot easier. If you don t have a homogenous sample, you might want to remove the «auto» function and test out different exposure times. The rectangular should be in this range before acquiring an image. This window is for the live image. The resolusion is not so good, and the refresh time is dependant upon the beam brightness. Yellow means too little light, red means too much and green means perfect illumination condition. This window is for the picture acquisition. Press start acquire when you want to take a picture. To change the settings for both live image and acquisition image, click onto the hammer sign (not 11 recomended).

12 Full resolution picture Preview picture After you press start acquire, the image will appear within a few seconds. The scalebar on the preview image is wrong, but the scalebar on the full resolution image is correct. 12

13 To save this image, go to file save image as, and save your image in the user-folder (shortcut on desktop). The image must be saved as a gatan file (dm3). This format is specific for the gatan software. You will export the images once you finish your session. 13

14 Converting dm3 images to tif After you ve acquired all your images, you can convert them to tif in the following way: File batch convert, find your folder and start the convertion from dm3 to tif. You will not loose your raw data, instead you will get extra copies as tif format. You can save the files temporarily on C:\users save here\ 14

15 Turning off the system when you have finished working 1. Make sure the camera is not inserted. Turn off the beam by selecting OFF in control window Turn off the HT by selecting OFF in control window. 3. You will be asked if it s ok to execute HT Mode OFF, select OK. 4. Turn off thee cooling (B) and the main power (A) for the gatan camera control box. 3. A B 15

16 Troubleshooting You should now see light on the fluorescent table. If it s dark: check if the current density is 0. If it s not, then turn up the brightness (on the control board) check that you are in the middle of your grid (specimen position window). Use the mouse to move around as you could be on top of a mesh. check if the camera is still inserted (through the software). If it s still dark, it could be a problem with the filament. contact Endy 16

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