Hi dear friends
As everybody knows, electromagnetic waves penetration depth have invers correlation with frequency. Whay the3 reason of Gama Ray penetration into the Skull (During Radiotheropay seances by Gama knife). During this type of radiothedrapy Gama waves focus on targeted tumor and tumor ablation occures during waves interaction. The question is this: according electromagnetic spectrum waves theory, the higher frequency the lower penetration depth. This view contradicts with mentioned explanations. Any one can help me. I really confused !!
thanks in advance
Behzad
there is no controversy! i.e. the frequency of gamma radiation is more than radio waves, accordingly the penetration of gamma radiation is low than radio waves. radio waves can travel 10s of kilometers in free space while gamma radiation could not travel more than 100 cm...
there are another point here: the energy per photon increases as the frequency increase. so, the gamma photons have so much high energy per photon that could kill the cancer cells.
The skin depth depends on the electric permittivity (and conductivity) and the magnetic permeability. These are functions of frequency. They are very different at the frequency of gamma radiation to what they are for example, with microwaves. Gamma radiation hardly interacts with tissue, as its wavelength (e.g. a picometre for 300 exahertz) is small compared to the size of an atom. When it does interact, it has a big effect because of the huge amount of energy in each photon (compared to the energy it takes to break molecules or ionise atoms), and it can do a lot of damage.
Dear Behzad Nasseri
Radiation therapy uses high-energy radiation to shrink tumors and kill cancer cells . X-rays, gamma rays, and charged particles are types of radiation used for cancer treatment.
Radiation therapy kills cancer cells by damaging their DNA (the molecules inside cells that carry genetic information and pass it from one generation to the next). Radiation therapy can either damage DNA directly or create charged particles (free radicals) within the cells that can in turn damage the DNA.
I would like to explain this mathematically:
If we consider a Radio wave an X-ray whose frequency are 300 MHz and 3*1019 Hz respectively now if energy associated along with wave wave can be calculated using the relation E=hf, where E=energy, h=plancks constant (3.326*10-23Js) and f=frequency of the wave.
This gives the energy of Xray is
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