Radionuclide,metastable radionuclides , Physics

Assignment Help:

Radionuclide is appropriate when several radioactive elements are involved.Most clinical diagnostics procedures used photons of some type usually gamma rays. Gamma rays with energies above 100 keV can penetrate many centimeters in the tissue.

Metastable Radionuclides :It is means half stable ,like 99m Tc which is one of man –made radionuclides that emits type of radiation not emitted by natural radioactive substance .A metastable radionuclide decays by emitting gamma ray only and the daughter nucleus differs from its parent only in having less energy. For example 99m Tc decays to form 99 Tc by emitting gamma ray of 140 keV .This is a very useful energy for nuclear medicine applications since it is penetrating enough to get out of the body easily and it is easy to shield with a few mm of lead. When a metastable radionuclide is used internally the absence of beta rays greatly reduces the radiation dose to the patient.

 

Types of disintegrations in man –made radionuclide :


1.The emission of positive beta (+β) or positron
: this will lead to annihilation radiation ,It is accrue when the emitted positron annihilate with an electron ,energy equivalent to their masses (511keV each) is usually emitted this annihilation radiation is useful for mapping the distribution of positron emitters in the body.

2. Electron capture: The nucleus can capture one of its own electrons (usually K) which then complain with proton in the nucleus to form another neutron and thus reduces the charge on the nucleus for example the decay of 125I ,a characteristic (kα or kβ) x-ray is always emitted after k capture.
After 125I   has swallowed one of its own electron to become 125Xe the nucleus has 35 keV  of energy which is some times emitted as 35 keV gamma ray ,or the nucleus transfers this energy directly to the remaining K electron which then uses the energy to escape leaving another vacancy in the K shell, This is called internal conversion or isomeric transition(IT).

 

 

1555_Radionuclide,Metastable Radionuclides.jpg


Related Discussions:- Radionuclide,metastable radionuclides

How the angle of the sun''s rays changes, Demonstrating how the angle of th...

Demonstrating how the angle of the sun's rays changes from day to day at the same hour Cut a 1-cm round hole in a piece of paper or cardboard. Place this in a south window of y

Young modules, to measure the extension of an experimental wire due to diff...

to measure the extension of an experimental wire due to different pulling forces using searle''s apparatues.hence, determine the young modules of the material of the wire.

Damped and undamped eletromagnetic waves , What is damped and undamped elet...

What is damped and undamped eletromagnetic waves Ans) A damped wave is a wave whose amplitude of oscillation decreases with time, eventually going to zero.

Define persistence of hearing, The impression of sound heard by our ears pe...

The impression of sound heard by our ears persist in our mind for 1/10th of a second. If another sound is heard before 1/10 second is over, the impression of the two sound mixes up

A lever of the first class, A lever of the first class Saw off a stick ...

A lever of the first class Saw off a stick or board so that it is the similar height as a heavy desk or table in the classroom. Place another stick about the similar length on

Right-hand palm rule, Stretch the fingers and thumb of right hand at right ...

Stretch the fingers and thumb of right hand at right angles to one another. Then if the fingers shows in the direction of field and thumb in the direction of current i, then normal

Motion in two dimensions, Motion of an object in a plane is known two dimen...

Motion of an object in a plane is known two dimensional (2-D) motions. For 2-D motion acceleration or velocity can be defined by two elements in any two mutually perpendicular dire

Determine the dimension, The control lever is subject to a clockwise moment...

The control lever is subject to a clockwise moment of P26 N.m exerted by its shaft at A and is designed to operate with a force of P27 N.  The resultant of the couple and the force

Can i light a house with a fiber optic, Can I light a house with a fiber op...

Can I light a house with a fiber optic? A house can be light with anything, by candles and gas lamps to fiber optics. However, there is the question, of the efficiency of the s

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