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

Evaluate the external-internal pressure difference, There is a maximum dept...

There is a maximum depth at which a diver can breathe through snorkel tube because as the depth increases, so does the pressure difference, tending to collapse the diver's lungs. S

What is meant by the sensitivity of a potentiometer, What is meant by the s...

What is meant by the sensitivity of a potentiometer? A battery E 1 of 4 V and a variable resistance R h are linked in series with the wire AB of the potentiometer. The length

Explain radio waves, Radio Waves: Radio waves are electromagnetic waves...

Radio Waves: Radio waves are electromagnetic waves with large range of wavelength from a few millimetres to many meters.

What is the electron''s speed?, An electron follows a helical path in a uni...

An electron follows a helical path in a uniform mag-netic field of magnitude 0.300 T. The pitch of the path is 6.00 um, and the magnitude of the magnetic force on the elec-tron is

Explain transverse waves, Transverse Waves: The traveling waves in whic...

Transverse Waves: The traveling waves in which particles of the elastic medium vibrate about perpendicular to the direction of propagation of waves are known as transverse wave

Circular motion, A car of mass 800 kg is pulling a trailer of mass 300 kg u...

A car of mass 800 kg is pulling a trailer of mass 300 kg up the slope of angle ? to the horizontal where sine ? = 1/200. Resistance to motion (apart from gravity) is 1.5 N per kg o

Extrapolate the experimental data to predict the pressure, Water at 20°C fl...

Water at 20°C flows through a long, straight pipe. The pressure drop is measured along a section of the pipe of length 1.3 m as a function of average velocity through the pipe. Res

Distinguish between the terms average value and rms value, A convex lens of...

A convex lens of refractive index 1.5 has a focal length of 18 cm in air. Measure the change in its focal length when it is immersed in water of refractive index. Distinguish am

Low of succeve disintigration, Dirive an expretion for low of succecive dis...

Dirive an expretion for low of succecive disintigretion

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