DWJ's+10.29-11.02


 * **10/29/07 Monday**

On Friday, I went to ND to search SEM. I have got many information about SEM, and also I have tried to use SEM too, ND's SEM has problem of picturing images. I have watched videos and listened lecture.

There are essentially 2 types of electron microscopes; SEM which permits one to distinguish minute differences in the external surface of an object and the transmission electron microscope which permits one to observe detailed structures of a very thin section of an object. ||
 * **10/30/07 Tuesday**

Today, I have read the book that Brighid Corcoran gave to me. It says a lot of things about SEM. A section that I read is how SEM is made up of.

The SEM is made up of two main comparments - the eletron gun column with the lower specimen chamber and the control/focusing console with the viewing screen. The electron gun (this looks like a gun, and it shoots electrons. I think that's why it is called electron gun) column has a tungsten filament near the top which when heated emits electrons which are directed downward in a beam due to a positive anode lower in the surface area of the specimen.



Modern SEM ||
 * **10/31/07 Wednesday**

I searched more deeply about electron gun today. A PC has been connected to the Learning Center SEM which means digital pictures can be generated as opposed to polaroids. || Today, I wanted to know how the SEM shows objects or samples, so I have searched how SEM works for that. SEM uses something similar to a light bulb to produce electrons. This is called the filament. The filament is a piece of wire and when electricity goes through it, not only is light given off, but also electrons. These electrons are focused by a series of magnets. The magnets are made magnetic by electricity and are called electromagnets. The electrons can be focused on the sample and when they hit the sample a signal is given off. A special type of detector acts like a TV camera and the image of the object is displayed on a tv screen. By changing how the electrons are bent and how the beam of electrons strikes the object, you can change the magnification and focus of the TV image.
 * I wanted to put some pictures of electron gun that I have taken at ND, but since this wikispace doesn't let me do it, I will put it later. *The electron gun column has a tungsten filament near the top which when heated emits electrons which are directed downward in a beam due to a positive anode lower in the column. After passing through focusing magnets the beam of electrons strikes a small surface area of the specimen. The beam moves ( scans ) back and forth over the surface of the object.The electrons in the beam interact with the elctrons in the atoms of the object causing some of their electrons (Secondary electrons) to be released. These electrons are detected by a detector and their signal changes the brightness of the electron beam on two CRT screens, forming an image. The image on one of the screens can be viewed by the operator.The second screen with the same image can be photographed.
 * **11/01/07 Thursday**

Today was a Half day ! yeah! I have got a picture taken from SEM I could see fly's face is not smooth.
 * 11/02/07 Friday**



23" x 19"
 * Black Fly
 * 1) DS-01** ||