Nps, neq, and dqe of x- ray detector, Physics

Assignment Help:

NPS, NEQ, and DQE of X- Ray Detector

1. An Example of a deterministic blurring. The digital flat panel detectors use discrete pixels to collect scintillation light from the phosphor. Each pixel integrates the light incident to its surface. Suppose the size of the pixel is a. When simplified to 1D case, this stage equivalents to convoluting the input quanta flux q(x) with a rectangular function (1/a) rect (x/a). Find out the MTF of this stage.

2. Phosphor screen of an x-ray imaging detector is exposed to monogenic 50keV x-ray. The absorption efficiency of x-ray photon is 50%. The absorption is assumed only through photoelectric effect and ignores the k-x-ray escape.  Thus, each absorbed x-ray will have an average of 100 scintillation light photons coming out of the phosphor. The blurring due to light scatter and spreading can be described by a MTF curve showing in the figure. The scintillation light photons are to be collected by a photo sensor, which have an efficiency of 40%. The average incident flux of 50 keV x-ray quanta is 1000 quanta/mm2 (q0)

204_NPS, NEQ, and DQE of X- Ray Detector.png

Please calculate the NPS, NEQ, and DQE of this x-ray detector at spatial frequency of 0 and 2.0 line-pair/mm.

(You should use a cascaded system to describe the phosphor. Calculate the NPS and NEQ after each stages, you only need to calculate DQE after last stage)

The tricks to solve this problem are:

1. Break the system down to cascaded stages and identify the type of each stage.

2. Write down the character of each stage: average gain, variance of gain and MTF.

3. Start from the first stage (incident x-ray) and transfer (or prorogate) the quanta (q),  NPS, SNR and NEQ through the stages, until you reach the last stage.

4. VERY IMPORTANT!  The quanta q, NPS and NEQ output from the previous stage will be the input quanta, NPS, and NEQ of the next stage.

5. Calculate DQE by the ratio of NEQ_out of the last stage to the NEQ_in of the first stage.


Related Discussions:- Nps, neq, and dqe of x- ray detector

Elastic Potential Energy/Spring Constant, I need help solving an equation o...

I need help solving an equation or two to find the elastic potential energy of a spring when compressed. Spring starts at .75 m, and is compressed to .25 m by a force of 12 newtons

Deuterium and tritium, Why is it easy to fuse hydrogen isotopes deuterium a...

Why is it easy to fuse hydrogen isotopes deuterium and tritium than ordinary hydrogen?

Explain frequency, Frequency The number of vibration done per second by...

Frequency The number of vibration done per second by an oscillation body is known its frequency. It is denoted by V. The S.I unit is Hz. V=1/T

Michelson inferometre experiment, Why the fringes are in circular form and ...

Why the fringes are in circular form and how does it form?

Give the overview of newton formulation of physical laws, Give the overview...

Give the overview of Newton formulation of physical laws. Newton's formulation of physical laws was so influential which his equations are still in use nowadays. By the beginni

Laws of motion.., A monkey of mass m climbs a rope slung over a light frict...

A monkey of mass m climbs a rope slung over a light frictionless pulley.The opposite end of the rope is tied to a block of Mass M lying on a smooth horizontal plane.Find the accele

What is the meaning of rate constant in the rate expression, A reaction is ...

A reaction is first order in A and second order in B. (a) Write differential rate equation. (b) How is the rate affected if the concentration of B is tripled? (c) How is

Stationary on inclined plane, A metal rod of mass 10 g and length 10 cm is ...

A metal rod of mass 10 g and length 10 cm is placed on a smooth 60 degree incline. A uniform magnetic field B is applied in the region vertically downwards . If a current of 3 A is

Determine focal length of this entire system, Two positive lens L 1 and L ...

Two positive lens L 1 and L 2 has the same focal length f>0. The distance between them is f/2. L 1 is placed to the left of L 2 . (a) An object is placed to the left of L1 wi

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