how can we focus electron beam?
96221
use a collimator.or magnetic fields.
715593
yes in theory a small laser can be attached to nano machines to cut through matter, but we dont have the ability to create them yet.\n\nHowever, this is  not the best solution to destroying a meter, we could simply nuke it, or divert its dirrection if its in earths path
141111
Its like a microwave for metals, only kilohertz instead of gigahertz.  Its done with a coil instead of a magnetron.
1129376
You are referring to particle physics. In particle physics experiments beam of particles are accelerated and made to collide with a target, either another particle beam or a fixed target. Particle detectors around the collission point detect the debris of the collision which permits to deduce what happened.\n\nThe energy of these beams are usually given in units like GeV (giga electron volt) or MeV (mega electron volt). 1 MeV is the energy of a beam accelerated by a potential difference of 1 million volt. 1 GeV is 1000 times more.\n\nIntermediate energy refers to the energy of the particle beam. It is a somwhat subjective term.  High energy beams would be beams \nwith above 10 GeV. Low energy below 10 MeV. Intermediate energy everything in between.\n\nA scintillator detector is a type of particle detector. A particle traversing a scintillator counter will ionise the material and produce light usually in the blue and green regions. The photons are detected by photo amplifiers and transformed into an electrical signal. \n\nThe source leads to an introduction to particle physics.
173992
Well, I don't think it was discovered, but rather developed (or invented)... here's a quote:\n\nPrior to 1930, all microscopes were optical. In 1931, German physicist Ernst Ruska developed the electron microscope that used a beam of moving electronics to illuminate an object instead of light. Magnetic lenses or electric coils produce magnetic fields to deflect the electrons in the same manner that glass lenses bend light rays. The specimen has to be in a vacuum, however, because electrons cannot travel through air. Electron microscopes give point-to-point resolutions of less than 0.2 nanometers. This high resolution permits the direct visualization of many molecules and some atoms.
851333
Depends on the type of monitor you have - lets assume the old tube type monitor.  In that case, the entire monitor inside the shell is a big vaccuum tube with something called an electron gun in the back.  There is phosporous compounds on the back of the glass.   The electron gun fires a particle beam at the back of the glass starting at the top left and then move to the right.  WHen it gets to the right side, it goes back to the left and down a line (I won't got into interlacing - you can look that up).  This continues until the beam gets to the lower right corner and then it shuts off and goes back to the top left and starts all over.  \n\nSo, there is a constant beam going across your screen in that typewriter fashion - it happens many times per second (depends on the monitor - this is your refresh rate).  What happens when the beam hits the glass - well, the phosphorous glows.  For each little spot on the screen, there are three colors - red, blue, and green - that can be lit up by the particle beam.  The combination of colors gives you the screen.  The more spots you have that you can light up as a rgb unit, the better the resolution on your screen.\n\nHow is this electron gun moved?  Well, it doen't really move.  The  direction of the beam is altred by electromagnets aroudn the yolk of the glass tube (the yoke is the smaller part near the back).  power is applied to the magnets to control or bend the electorn beam.  These control magnets are controlled by the inputs from the video card from the main pc.\n\nSo, if you opened up an old tube TV or tube based (analog) monitor, you will find a big vaccuum tube wiht wires running around it and a circuit board or two.\n\nLCD and plasma work a bit differently.
935132
keep it far from electrodomestics\n\n:> peace\n.
1057571
lol\ni did this assignment before. i also had to research in on line because it was gong to be in my exams\n\nit really easy\n\nyou got to yahoo search engine and type microscope and click image search. you will find tons of microscope pictures from the very basic hand drawn kinds to state of the art compound electron microscope
66276
below i am enumerating the differentiatin points :-\n1)LIGHT MICROSCOPE>>this is also called optical microscope and it uses light as source of illumination.> image here is produced due to selective absorption of light by different parts of object.>this microscope doesn't require vacuum.>it employs ordinary glass lense and doesn't need magnets.> high voltage electricity is not required.>specimen is kept in liquid medium or a resin.>microscope is small n portable.>radiation risk absent.>contrast in image is achieved by use of dyes like fast green safranin.> image of stained specimen is coloured.\n2)ELECTRON MICROSCOPE->>source of illumintn is electron beam.>image obtained due to selective scattering of electrons by diff molecular components of object>image is black n white>no staining>apparatus enclosed in vacuum>glass lenses not used>electromagnetic lenses of high power used>microscope is large n fixed>radiation risk exists>specimen must be completely dry>high voltage current req to generate electron beam>contrast in image is achvd by use of heavy metals like lead acetate n phosphotungstate>spcmn is ultra thin\nand ah yes resolving power of lght mcrscpe is 0.25micrometre-0.3micrometre while\nfor electrn mcrscp, 2-10 angstrom though theoretically should be 0.25 angstrom.
147555
Yes but the range you require would not be possible. Gamma rays spread out. You cannot reflect it into a fine beam.\nSo it is very difficult. However if you invent one .I would strongly advice u not to kill all...(or for that matter any) humans using it:-)
1046710
1. make sure the specimen is actually under your field of view. then, keep adjusting the focus knobs gently until it comes into focus. also, you might want to restain your specimen.
1050299
To the best of my knowledge, it has to do with the fact that the scanning electron microscope (SEM) takes pictures progressively and the transmission electron microscope (TEM) takes a single image.  A TEM can be used to take multiple images if the item being scoped is sliced before and each slice is individually prepared (dehydrated, gold ion transfer, etc....it's been a while, sorry!), but the SEM will take images in a method similar to that of an MRI or CT scan - in progressive slices.
420181
no and yes,\nyou cannot "see" it with a big microscope and your eyes since the wavelength of light is larger than an atom. \n\nBUT using a beam of electrons, which have wavelengths smaller than an atom, you can use equipment that can detect the reflected electrons. this is the concept behind an electron microscope, like the previous poster talks about.\nhttp://en.wikipedia.org/wiki/Electron_microscope
28523
Simply speaking; x-rays are produced by first accelerating electrons toward a metal target. Usually tungsten.\n\nSo you know.....your tv set is an electron accelerator.\n\nUsually tungsten. When the electrons strike the metal, they impart their kinetic energy to the electrons of the metal atoms.\n\nIn so doing, those electrons change to a higher shell, or orbital around the nucleus of the metal atom. Since they do not want to reside there very long, they quickly decay.\n\nBut in order to decay they must give up the energy they used to get to this higher (energy) level shell. This energy is given off as a photon (light), but the wavelength is that of what we scientists call an x-ray.\n\nThis wavelength is beyond the visible portion of the electromagnetic spectrum so we cannot see it, but somewhat solid objects can stop them. This is why we can use them to see our bones and in other inspection type configurations.\n\n:)
206990
focus on a point in front of you.\n\nbetter yet, focus on TWO POINTS
353533
If you could find a transition between an inverted state and a ground state of 1 joule, you could probably make a laser of that frequency. At this point, hard gamma rays are the limit we have done.
18708
One way is to strip off a bunch of its electrons with\nlight pulses or with charged plates...and then send\nit to circulate through a curved magnetic field\n(since the atom has lost some electrons, it is now\ncharged, and charged particles speed up when you\nput them into a curved magnetic field). When you get\nthe atom going really really fast, change the field\nand let the particle slam into a target. Sort of\nlike throwing an alarm clock against a wall really hard....\nthe atom smashes open and we see its "insides"\ncome screaming out (using a special detector).\n \nThis is called a "particle accelerator,