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.
experiment measuring moment of magnet
does lights of different wavelengths help us to see different colour
One source of a star's energy is the fusion of two deuterons to form an alpha particle plus a gamma ray. a. Write down the nuclear equation for this fusion. b. Measure the m
Ratio of masses of proton and electron is: (1) Infinite (2) 1.8x10 3 (3) 1.8 (4) None of these Ans: (2) 1.8x10 3
If Joe rides his bicycle in a straight line for 15 min with an average velocity of 12.5 km/h south, how far has he ridden?
Q. Illustrate why does the pilot tilt the outer wing of the airplane inward while taking a turn? Answer:- Airplanes have two control surfaces implicated when turning the a
For an enzyme that follows Michealis-Menten kinetics, the initial velocity at different substrate concentration has been determined. [S] (mM) 0.1 0
Construct depletion MOSFET
Why is it that the frequency of light remains the constant as it undergoes refraction at the interface of two material mediums? Ans) If frequencies are dissimilar in different m
A flow rate of 200 gpm of oil with u=1.5 x 10 -3 lb-sec/ft2 and p=1.7 slug/ft3 occurs in a 4-in pipe. Determine the Reynolds number. Classify the flow as laminar or turbulent. Wha
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: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd