Sodium iodide crystal (nai), Physics

Assignment Help:

Sodium iodide crystal (NaI)


It scintillate with good efficiency when gamma ray is absorbed, these crystals where attached directly to the PTM to detect a weak flashes of light .They where improved by adding a trace amounts of thallium(Tl)and often referred as NaI(Tl) detector. It is the most widely used detector in medicine .

A nuclear medicine scintillation detector system


1-Scince the NaI(Tl)detector is very sensitive ,it has to be well shielded from background  radiation .
2- five or more cm of lead surrounding the NaI(Tl)crystal except at the collimator .
3-The electron emitted at the photocathode of PTM produce an electrical pulse  at the output .
4-this pulse is electronically amplified at the amplifier.
5-The pulse can be directly counted by the scalar.
6-The pulse pass to the single channel  pulse height analyzer(PHA) to determine the energy of the gamma rays

It contain  an upper discriminator (it rejects the pulses larger than a chosen size)

                  lower  discriminator ( reject the pulses smaller than a chosen size)

                 window(it is the energy difference between the upper and lower limits )


Multi Chanel analyzer (MCA): it determine the pulse height distribution of all the pulses from the detector ,so it sorts the pulses according to the size.

 

12_Sodium iodide crystal (NaI).png


Related Discussions:- Sodium iodide crystal (nai)

Friction, why friction is called a necessery evil?

why friction is called a necessery evil?

Determine the input bias current, The op amp shown in Figure has an input b...

The op amp shown in Figure has an input bias current of 100nA at 20 ? C. Measure (a) The voltage gain, and (b) The output offset voltage due to the input bias current. (c

Correction of short sightedness, Correction of short sightedness To rem...

Correction of short sightedness To remove this defect a convex lens is used in front of eye.

Find the normal force, The mass of an automobile is 1140kg, and the distanc...

The mass of an automobile is 1140kg, and the distance between its front and rear axles is2.48 m. The center of gravity of theca is between the front and rear tires, and the horizon

What is angular velocity, The power of change of angular displacement with ...

The power of change of angular displacement with respect to time is known as angular velocity.

Seeing your whole body in a flat mirror, Is it possible to see your whole b...

Is it possible to see your whole body in a flat, planar mirror that is LESS THAN half your height if the mirror is at an angle? (i.e. not parallel to your body)

Point out the direction of the current, Point out the direction of the curr...

Point out the direction of the current if any induced to flow in the coil by the changing magnetic field. (Depicted is a view of the coil from the side. Toward the top of the displ

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