Magnification in scanning electron microscope, Physics

Assignment Help:

How is magnification in scanning electron microscope controlled?

Magnification in scanning electron microscope:

Magnification into a SEM (scanning electron microscope) can be controlled over a range of regarding 5 orders of magnitude start from x25 or less to x 250,000 or more. Not like optical and transmission electron microscopes, representation magnification into the SEM (scanning electron microscope) is not a function of the power of the purpose lens. SEMs (scanning electron microscopes) may have objective and condenser lenses, but their purpose is to focus the beam to a spot, and not to illustrate the specimen. Given the electron gun can produce a beam with sufficiently small diameter, a SEM (scanning electron microscope) could in principle work fully without condenser or objective lenses, although this might not be extremely versatile or attain very high resolution. In an SEM, as in scanning probe microscopy, magnification results through the ratio of the dimensions of the raster onto the specimen and the raster onto the display device. Assuming which the display screen has a fixed size, higher magnification results by reducing the size of the raster onto the specimen, and vice versa. Therefore Magnification is controlled through the current supplied to the x,y scanning coils, and not through objective lens power.


Related Discussions:- Magnification in scanning electron microscope

Simple pendulum frequency, A simple pendulum of frequency f has a metal bob...

A simple pendulum of frequency f has a metal bob.If the bob us negatively charged and is allowed to oscillate with a posively charged plate under it , the frequency will.? Ans) DUE

Evaluate frequency to shatter the glass, Evaluate frequency to shatter the ...

Evaluate frequency to shatter the glass with a resonant vibration? Standing-wave vibrations are set up in a crystal goblet with four nodes and four antinodes equally spaced arou

Pendulum, a pendulum is timed ,first for 20 swings and then for 50 swings ;...

a pendulum is timed ,first for 20 swings and then for 50 swings ; time for 20 swings = 17.4 sec and time for 50 sec = 43.2. calculate the average time per swing/

Physics, Current time base generator

Current time base generator

Straight line motion with gravity, a ball is thrown upward from the top of ...

a ball is thrown upward from the top of a building 60m hign with an initial velocity of 49.0 m/s. when is the ball 78.4 meters above its starting point?

How is plastic clad silica fibre used in optical fibres, How is plastic cla...

How is plastic clad silica fibre used in optical fibres? Plastic clad silica fibre: Plastic clad silica fibre (PCS) is other type of optical cable. This has an attenuation l

Give the applications of moseley''s law, Q. Give the applications of Mosele...

Q. Give the applications of Moseley's law. (i) The elements are organized in the periodic table according to the atomic numbers and not according to the atomic weights. (ii

If the ray is a principal ray where does it go from there, Portrayed is a r...

Portrayed is a ray from an object which heads toward and then into a lens. Suppose if the ray is a principal ray where does it go from there? Ans: This is the simple p

What is normal reaction, What Is Normal Reaction ?How To Find It? Norm...

What Is Normal Reaction ?How To Find It? Normal reaction is the force acting among two contact surfaces. Like, if you push a wall, you will feel an opposite force acting on yo

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd