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X-rays (1 Viewer)

GaNeSh

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hey if they ask something like describe how xrays are currently produced...is is enough to get full marks if i say electrons accelerated blah blah blah...and hit the metal target or anode and rapidly decelerate, causing the kinetic energy of the electrons to converted into xrays(1%) & heat(99%).?? is that a correct explaination of how xrays are produced?
 

biscuit

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That is correct by my understanding, however in order to gain full marks you would also have to mention the underlying physics behind how X-radiation is produced

e.g. talk about the Bremsstrahlung ionisation that occurs - and how the amount of 'braking' of the electron will determine the frequency of the electromagnetic radiation released

This occurs when the electrons hit the tungsten target
 
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Haku

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biscuit said:
That is correct by my understanding, however in order to gain full marks you would also have to mention the underlying physics behind how X-radiation is produced

e.g. talk about the Bremsstrahlung ionisation that occurs - and how the amount of 'braking' of the electron will determine the frequency of the electromagnetic radiation released

This occurs when the electrons hit the tungsten target
wat? the electrons deceleration depend on how much voltage is proved. also it gives out a whole spectrum of waves, some of it being x-ray. the faster the electron = faster deceleration = more x-rays due to more energy, as x-ray on the high end of the spectrum.

talk about the other method, where the electron from the cathode knocks out an electron in the inner shell of the tungsten target. electrons in higher orbit fill the gap and release energy as x-rays, these are hard x-rays.
 

biscuit

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Yeah, you can mention either method -

Perhaps the ionisation method is better for medical physics; where the inner shell electron is knocked out, and thus is replaced by an outershell electron - the energy difference between the two electrons determines the frequency of the electromagnetic radiation

I could be wrong though, read jacaranda!:)
 

Haku

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ur right. lol dun have jackaranda. but i reckon u need to talk about both. even though i say they are different methods, i just dun see the difference!!!.

if decelerates by hitting the tungsten target. which causes electrons knock outs. so its the same thing... wtf
 

biscuit

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Haha shit, now i'm confused!
They are probably the same thing then, it would make sense. When the electron hits the tungsten target, the deceleration that occurs transfers the energy into heat and electromagnetic radiation.

then talk about electron shell's blah blah

and thats full marks:D
 

Haku

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lol, glad u see the sameness of it. when i explain to other people they just dun see it!!!

but yea i think its the same. but all books say it separately.
 

biscuit

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Well, if you mention both the examiners will be impressed

Not many people know how to articulate the physics behind the production of X-rays, its pretty complicated stuff, i think its one of the more complicated aspects of MP as well as MRI scans
 

Haku

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u rekon?

just another question, beside the calculation of Z and ratio of deflection is there any other calculations in med phy?
 

Abtari

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biscuit said:
Well, if you mention both the examiners will be impressed

Not many people know how to articulate the physics behind the production of X-rays, its pretty complicated stuff, i think its one of the more complicated aspects of MP as well as MRI scans
wth how is production of x-rays an aspect of mri scans???
 

Jago

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nosadness said:
wat? the electrons deceleration depend on how much voltage is proved. also it gives out a whole spectrum of waves, some of it being x-ray. the faster the electron = faster deceleration = more x-rays due to more energy, as x-ray on the high end of the spectrum.

talk about the other method, where the electron from the cathode knocks out an electron in the inner shell of the tungsten target. electrons in higher orbit fill the gap and release energy as x-rays, these are hard x-rays.
i always thought you needed to talk about both methods to gain the full marks..

Edit: they're similar in that they're both difficult to understand, i think thats what he's saying
 

Haku

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nono, thats so not what i am saying.

ie: for an electron to decelerate a quick speeds it needs to hit the tungsten target. But hitting the tungsten atoms will cause a inner electron to be knocked out and the energy released when an outer electrons falls back to the inner shell create x-ray, but so do the deceleration. So this occur simultaneously, so its the same method. one cannnot happen without the other.
 

Abtari

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who told you these are the same methods?

wrong! (in my opinion anyway)

these are separate ways in which x-rays are produced. when the accelerated electrons collide with electrons in inner orbits of anode atoms, and electron from outer orbit drops down to inner orbit etc... that forms a single frequency-type radiation....

but with the deflection due to attraction to positive nuclei of anode atoms, they produce another type of x-radiation i.e. a range of frequencies...it's not just one single frequency radiation.
 

biscuit

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Abtari said:
wth how is production of x-rays an aspect of mri scans???
I just ment that X-ray production is one of the more harder aspects of the topic, likewise with understanding MRI scans :)
 

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