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

Volt meter, Ask question #Minimum 200 words accepted#

Ask question #Minimum 200 words accepted#

Explain law of conservation of momentum, LAW OF CONSERVATION OF MOMENTUM. ...

LAW OF CONSERVATION OF MOMENTUM. "The total linear momentum of an isolated system always constant"                                  OR  "If there is no external force ap

Define teacup engine, Define Teacup Engine? The astronaut was calmly dr...

Define Teacup Engine? The astronaut was calmly drinking tea at five o'clock galactic time, as was his wont, when he had an urgent situation outside the shuttle and he had to do

Determine the magnification produced, An object is placed at a distance of ...

An object is placed at a distance of 0.12m from a convex lens forms an image at a distance of 0.18m. Determine the magnification produced.

Explain the conservation of energy, Conservation of Energy Conservation...

Conservation of Energy Conservation of energy is not all about turning off the computer when you are not using it. Energy is not created or destroyed, it just changes forms. En

Determine joules of heat if energy dissipated by resistor, The potential di...

The potential difference across a 4 ohm resistor is 20 volts.  Assuming that all of the energy dissipated by this resistor is in the form of heat, how many joules of heat are radia

A lever of the second class, A lever of the second class Use a uniform ...

A lever of the second class Use a uniform wooden bar about 1 m long, 4 cm wide and 5 mm thick. Drill a hole near single end, in the centre of the width dimension. Also drill a

What is non-inertial frame of reference, NON-INERTIAL FRAME OF REFERENCE: ...

NON-INERTIAL FRAME OF REFERENCE: A frame which has non-uniform motion but particular acceleration is known as non-inertial frame of reference. Newton's first law of motion i

What instrument is utilized to measure volume, Q. What instrument is utiliz...

Q. What instrument is utilized to measure volume? Answer:- Liquid volume is measured with graduated cylinders, beakers, measuring cups, spoons and the like. For regular ob

Dimension, dimension of electric current

dimension of electric current

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