Sodium iodide crystal (nai), Physics

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

Posted Date: 10/1/2012 7:05:10 AM | Location : United States







Related Discussions:- Sodium iodide crystal (nai), Assignment Help, Ask Question on Sodium iodide crystal (nai), Get Answer, Expert's Help, Sodium iodide crystal (nai) Discussions

Write discussion on Sodium iodide crystal (nai)
Your posts are moderated
Related Questions
Describe the Michelson Morley's experiment and explain its negative result. What is "Length Contraction" and "Time Dilation" in relativistic mechanics? Explain.


The electric potential at a point in a consistent electric field in an evacuated region of space is 4 . 0 volts. The electric potential at a end 25 cm to the east of the first poin

What do you mean by pure spectrum? What is an impure spectrum?

Ask question how to plan and design a lab to measure the maximum recombination time of ions produced by a flame

Advantages of fibre optics: Fibre-optic communications systems have a large bandwidth, e.g. 1 GHz.  The bandwidth is the maximum rate at which information can be transmitted.

Difference between Fission and Fusion Fission                                                                                         Fusion 1. Heavy metal is divided int

Reducing friction with ball bearings  Find two tin cans that have a deep groove approximately the top, such as paint cans. Lay marbles in single groove and invert the other can

Meissner effect (W. Meissner; 1933): The reduction of the magnetic flux in a superconducting metal while it is cooled below the transition temperature. i.e., superconducting m

The primary coil of an ideal step-up transformer has 100 turns and the transformation ratio is also 100. The input voltage the power are 220 V and 1100 W respectively. Calculat