X Rays - A Level Physics

A basic description of the production of X rays for medical use in remote sensing. Part of the A Level Physics revision series.

[@jacktoholke6378]

Thank you so much! Very well X-plained!

[@AS-qi2lq]

I see what you did there.

[@tpodan79]

You explain so clearly in 18 minutes what took my teacher 50 minutes to explain and I still didn't get it. Thank you for an excellent explanation!

[@DrPhysicsA]

Thank you for your very kind comments. I'm very glad that it helped.

[@bikermoofrommars5922]

I'm a dental nurse studying for my radiography qualification and have been struggling with understanding some areas of physics. Just wanted to say how amazing this video is, and I'll be watching on repeat and taking revision notes from this ( aswell as my textbook of course!). Thanks so much

[@DrPhysicsA]

Hi Jake - Thanks for your kind comments. I would be very happy to do the videos you suggest but I'm afraid I cant do them in time for Monday and probably not for another week or so. But good luck in your exam. I hope it goes well.

[@anikasanjana6912]

This is so amazing! These explanations follow the exact contents which are in the application booklet, also maintaining the serial. Loved it!

[@DrPhysicsA]

In general ionisation means that an electron has been knocked out of an atom so that the atom is positively charged (ionized). Excitation means that the electron has been pushed up to a higher energy level (but still within the atom). The atom still has all its electrons and is not ionised. But the excited electron will soon fall back to a lower energy level emitting a photon.

[@a7med4s]

Perfect presentation,perfect demonestration I am so happy to watch this DrPhysicsA you are simply incredible

[@benjamincharles5492]

WOW! This is the best explanation of X-Rays...!! Thank you!

[@NWin86]

Thank Dr for uploaded this kind of professional lecture. It help me a lot.

[@andresjimenez3026]

Excellent video, has a wonderfully concise explanation.

[@thecontroller6786]

Great video!! Thank you so much for your explanation... All of your vids are all well-explained.

[@annagute7681]

The best x-ray explanation ever, THE BEST !

[@DrPhysicsA]

Yes. There is the braking radiation. But the main X rays come from high energy electrons knocking electrons from the inner shells of the anode. Outer shell electrons can then fall down the energy level to take the space vacated by the electron. This fall in energy is released as a photon - in this case in the X ray wavelength range.

[@MrKb7373]

Good simple explanation and useful practical/clinical tips. Just to correct one mistake DrPhysicsA in your explanation from 14:15 to 14:35, when x-rays strike the radiographic film it is blackened, not whitened or grayed. That is why the shadow of bone on the radiograph appears white or grey because the x-rays are attenuated by the dense bone. However the soft tissues do not stop the x-rays at all from penetrating hence that part of the radiographic film appears black.

[@valdemirpelegrinello7149]

Amazing explanation clearly and easy to understanding. Thank You so much

[@jakerichardson625]

Thanks anyway! Most of your videos cover most of the stuff, and have really made a difference for me. Thanks again

[@ilaydamumcuoglu8339]

finally I understood how x-rays work thank you so much for this amazing video

[@JennyCheng0102]

i learned so much in your video! biomedical imaging is making sense now! thank you!

[@Marimari-ev6rr]

I have my physics exam in a fee hours and I'm just watching this rn , lovely , but thank you sir for explaining everything in such a superb way !

[@IMrNuminous]

Glad I found these in time for my G485 exam, really good explanation. Feels like im getting a physics lecture off bruce forsyth :)

[@Mufti199]

U, my friend, are a life saver

[@1002em]

this is ridiculously helpful. thank you so much for these videos!

[@EllieGouldingFan]

I have the same exam on Monday - thank you so much for these videos! Good luck for Monday everyone! :)

[@DrPhysicsA]

My A Level Physics revision playlist has videos on Gravitation and Electricity, both of which refer to the inverse square law for Newton's or Coulomb's laws.

[@leeannhunt9122]

Wonderful explanation! This was super helpful!

[@razamate]

That was a really good explanation of xrays! Thank you very much!

[@vishvanthraja9165]

Really , the best explanation. Thank you very much

[@DrPhysicsA]

How kind. Glad it was of some help. All good wishes for your studies.

[@danielholden6849]

Thankyou for the great video, it really did help! I am just slightly confused with the graph. You said that were the minimum wavelength are seen high energy x-rays occur. On the y-axis there is intensity, so does that mean the x-rays produced on the left side of the graph have an high energy but low intensity?

[@DrPhysicsA]

Where x-rays are produced as a result of electrons falling from outer energy levels to inner energy levels then this will be a constant process because energy is constantly being given to the atom to enable electrons to jump up to the higher energy levels in the first place.

[@bostaphkatya]

Excellent! thank you so much for your explanation!

[@PaiigeeYeaah]

Ahhh everything makes so much more sense now! A big thank you to you!!!! :)

[@DrPhysicsA]

Thanks. Nice to know its recommended by your professor.

[@floridanews8786]

Beautiful explanation!

[@DrPhysicsA]

Ionisation is where the energy given to the electron (eg from a photon) is sufficient to kick the electron completely out of the atom. The atom therefore has a residual positive charge. Excitation is where the photon gives enough energy to promote the electron to a higher energy level but still in the atom.

[@vicky.medrano]

Best comprehensive explanation I've found. Thanks so much!! Just one critique; video quality ;)

[@syed5126]

Vicky Medrano its was made in 2012 what do you expect?

[@gautomdas9172]

Very very good one . just love it.

[@amanial-khalifa5299]

Excellent. Thank you!

[@vidulanarampanawa2540]

My ideal teacher of physics

[@DrPhysicsA]

Thanks. In my efforts to show where the X rays would penetrate and where they wouldn't I didn't properly cover their impact on the photographic plate. I've added an annotation.

[@TheBassHeavy]

Very well explained! Thank you!

[@reshamregmi272]

Thank you very much DrPhysicsA. It was very beneficial for me to learn physics in conceptual way. I think it would have been better if we can get your video in HD too.

[@biajidejajchowdhury1058]

Thank you professor, it's a great lecture.

[@emu98391]

You did a nice job! I think it will be help to review this when I study.

[@jasonbellamy9759]

This is fantastic - thank you so much!!!!!

[@jakerichardson625]

Hi I'm an A Level student and I have my AQA unit 5 exam on Monday, I find your videos so helpful. I learn more after watching them than I've learnt in all my lessons on those topics. If you have time would you be able to do some videos on other Medical Physics topics? such as the eye, ear, and heart? This is the stuff on my syllabus, if you could make a video on anything on here it would be extremely helpful!

[@Missamytta]

Awesome explanation! Thank you :)

[@streamleazefishhouse]

Awesome! I'm marking level 3 Btech course work and I'm a biologist...... Thank you!!!!!

[@confusion3146]

I just have a few questions, does the rotor part of the anode also rotate along with the disc? Which part of the mechanism actually controls the tube current, is it the tube part of the cathode or the thermionic filament? Also, the anode is the positive part but does this refer specifically to the disc of the anode or the rotor that's positive to attract the electrons?

[@ericpupek9044]

watched a ton of videos on x rays and sorry to say their are a ton of really bad Physics teachers out there, BUT your videos was awesome. Thank you I HIGHLY recommend.

[@shakirbaba6765]

Best explanation.. love it

[@samapanbhadury6228]

what happens to the electron when it delivers all its energy to radiation. zero kinetic energy implies it comes to a stop. But how is that possible?

[@MsSergey1313]

A excellent lesson! Thank you!

[@suppandi1000]

Hello DrPhysicsA, I'm a high school student. Just a little Q- The Duane-Hunt law (dealing with continuous radiation) is easy enough, but is there any theoretical derivation for Mosley's law? Thank you

[@nooli72]

My professor recommanded your video. thanks for great video.

[@luluahmed4079]

what happens to the projected electrons from the cathode if the metal anode melts? also thanx for the video very helpful! :D

[@zatulmutalif3230]

sir how do we know whether the x ray image produces a good contrast??the question that i did, the answer talk about the ratio of I°/I but i dont understand...

[@aal-dahir1773]

Help with a question sir Does changing intensity, changing penetration and changing voltage affect the x-ray spectrum?

[@smtsolutionanne6280]

How does an X-ray Tube Work (Radiation Protection)

[@weakwok3550]

why the electron accelerates round the nucleus release x-ray photon?

[@stervi2]

What would happen if an incident electron didn't make a head on collision with one of the tungsten electrons but got very close? would it excite the tungsten electron and that would then emit a photon when it falls back down to its original energy level? if so, would it emit x-rays?

[@Clintz83]

Thank you so much, this is really helpful!!!

[@Montymylie1]

Is ionisation when the x-rays are made and exitation when the are the body?

[@dvdmine]

Is there a reason we use tungsten as the anode?

[@DrPhysicsA]

Which A Level syllabus are you following?

[@twchen0402]

Dear DrPhysicsA: From the video, are you meaning the x-ray generation from the acceleration of electron beams is equivalent to that from the energy transition of the outer shell back into the inner shell. They are of the same, but different pictures. right ?

[@twchen0402]

I am sort of confused. So the braking radiation and inner shell electron transition are two different mechanisms. The latter is the usual way to generate x-ray. Right? and does the electron acceleration inside the CRT(cathode ray tube) create some long-wavelength x-ray or just the ultra-violet radiation ?

[@housseinmasri7704]

I want to know,how I can prevent cutoff?

[@rustyjeanz]

+DrPhysicsA Dear Dr. I got one question. At 14:00 why you draw the X Rays emerging from Anode not straight lines but around 15:00 you draw straight lines that are emerging from anode. Is this because the samples are bone and soft tissues respectively? If yes , but how do the X Rays know whats the sample. So Can you explain both cases considering the same straight lines emerging? Thanks

[@themrworf1701]

Thanks! You explained a lot!

[@hamnachaudhary4657]

You explained really well.

[@hartwiggrant4263]

I like this video, it helps a lot. Good Job, thanks...

[@rustyjeanz]

very nicely explained. Thanks a lot :)

[@kevinmun1]

Sir, I would like to ask.Like what you mentioned, high speed electron will hit the electron from the tungsten atom. And then the outer electron will jump into the inner shell to replace it. Energy lost is the X-Ray. After outer electron fall into the inner shell, The more outer electron, I mean will others electron replace the jumping electron? will X -ray produce also?

[@akshatasurati5448]

Precise and perfect

[@shaneellal1086]

This is very useful, thank you.

[@maiprue]

Hi Dr Physics A,, I'm confused.How can an electron being accelerated and at the same time losing energy(@min 4:15)?Also, it seems that accelerating and decelerating charges both emit radiation. When you said accelerating charges radiate light, do you mean that 1.the light is being radiated while the charges are being accelerated? or 2. (after the acceleration process is over) charges then decelerate and light is emitted as a result? To me, decelerating charges emit radiation makes sense but radiation is emitted while charges are being accelerated does not. Can you explain this in term of conservation of energy if that's possible? Thanks very much.

[@DrPhysicsA]

My videos certainly cover the OCR syllabus but they all so cover material in the AQA and Edexcel syllabus as well as some material in the Cambridge syllabus.

[@YaduPoudel]

Thank you. Your voice is amazing

[@drsheikh]

Excellent commentary.

[@DarkLevis]

Your welcome. I understand this but I assume there's a deeper reason to this. I'm guessing that low energy photons 'frequency' causes some interaction (resonace?) with molecules more easily that high 'frequency' does. Or is it just explain cause high freuquency photons pass due to having more energy(as some being absorbed but even few which pass leave a mark on plate) or even some other way? Thanks a lot!

[@nadalcathe3436]

I need some help with half-value thickness and linear attenuation coefficient. Can you help please Sir. :S

[@rucksapps]

Tungsten has a high electron density and, when hit by the electrons coming from the cathode, emits a characteristic x-ray, in that the waves have a high enough frequency and therefore, enough energy to penetrate the aluminium plate covering the tube and thus, enough energy to penetrate the bone etc to reach the lead (less penetrable material to absorb the photons)...

[@cusshoe]

Excellent video...

[@DrPhysicsA]

I'm stumped on that one I'm afraid. I guess the answer has to do with the technology and which element best provides the Xrays which are most suitable for medical purposes. But I could be wrong. Anyone else know?

[@pynewill]

Great video, but what about X-ray attenuation and image intensifiers, also contrast media and CAT scans are in the textbook

[@DrPhysicsA]

Thanks. Nice to have it explained.

[@moyrml]

that last part got me thinking about orthographic projection. is that grating essentially creating an ortho look? if it does then, is it possible to create an ortho-lens in that manner to attach to a regular (visible-light) camera? btw, great video, thank you!

[@adarshk19]

Hello awesome video that complemented my textbook and brought life to the application section of my physics course. Is there a video about the attenuation of X-rays? Like where we use the formula to fine resultant intensity and so on? thanks

[@nikoscharalampidis7153]

Wow. Great job.

[@DrPhysicsA]

Have you looked at "Attenuation coefficient" on Wikipedia?

[@aliciaroye7236]

Hi, Thanks for all your wonderful videos, been a big help in simplifying some topics in Physics. Do you have any lessons on the Inverse Square law? Thanks! Keep up the good work.

[@sameerprajapati2964]

but i think thermions are required for discharge of electrons doesnt it where are they produced

[@Cait09here]

Hi Thank you very much for your videos they are absolutely brilliant you explain things so well. I need to know what ionisation and excitation mean for my exam and from what I have gathered from your video because only 1% of electrons hitting the anode are converted into x-rays and 99% heat up the anode is this due to excitation and ionisation? Any help would be greatly appreciated :)

[@FakeDeath02]

This was very helpful thanks for the video

[@izzythomas9064]

Thank you so much this helped me a lot :)

[@soliltary]

Thnx for providing knowledge to people like us

[@MrKb7373]

You can add this correction as tag to your video for those minutes. [Reference: 'Nature of the radiographic image', pg. 3, Essentials of Dental Radiography and Radiology by Eric Whaites, 4th edition.]

[@Spirit-Consciousness]

Aweeeeeeeeeeeesomeeeeeeeeeeeeeeeeee videeoooooo .... u r the best physics teacher :) (y) subscribed..!