Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Megavoltage therapy:
Kerst developed the betatron which accelerates electrons to high energy .It open a new radiation therapy era-the supervoltage or megavoltage era.Another development in the radiation therapy is the application of man made radioactive source .
One of the radioactive sources:
Cobalt 60: it emits penetrating gamma rays of about 1.25 Mev energy.60Co units (also called cobalt teletherapy and cobalt bomb units)
-The high energy gamma rays emitted by 60Co are absorbed by tissue and produce high energy electrons .- Most of electrons move in the same direction as the original beam .- As the gamma ray beam penetrates the first few mm beneath the skin ,the no. of electrons increases and the energy deposited by them increases.- The dose maximum occurs about 5 mm below the skin .-The relatively low dose at the skin from high energy x-rays of gamma rays is referred to as the skin –sparing effect.-The radiation from 60Co teletherapy unit is emitted continuously ,the unit is turned on by rotating the source wheel until the source is over the beam port in the large lead shield .It is turn off by rotating the source wheel until the source shielded by the wheel fig (1).
Mega voltage therapy has three major advantages :
- The maximum dose occurs below the skin and the skin sparing effect greatly reduces the pain from the treatment.- The high energy is almost completely in the Compton effect region and doses not give a large doses to the bone .- The greater penetrating ability permits better treatment of tumors deep inside the body.
define biased clipper?
What is motion
A negatively charged particle is cranium due north straight toward a straight vertical wire which carries a downward current. What is the direction of the force if any use on the c
Metallization: It is the process of giving electrical connections among different parts of the circuit. Aluminium is commonly used. It has a high electrical conductivity and a low
Example of state function
COHERENCE : 1) Visible light energy is emitted when the excited electrons in atoms undergo transitions to the ground state. 2) In ordinary light sources, these transitions
Automatic gas generator This is a semi-micro Kipps apparatus. The solid reagent (zinc, marble, iron sulphide, etc.) is placed in a large test tube with holes in it, and the aci
Explain Simple Harmonic Motion Many repeating motion problems can be solved by taking the displacement as where d is distance in meters, A is amplitude in meters,
Do you write essays for a fee?
Sievert; Sv: The derived SI unit of dose equivalent, explained as the absorbed dose of ionizing radiation multiplied through internationally-agreed-upon dimensionless weights,
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!
whatsapp: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd