-2
\$\begingroup\$

What are the reasons X-ray vacuum tubes could not be replaced by solid state alternatives?

I'm thinking if it is possible to make a compact solid-state X-ray or higher energy photons generator just like how vacuum tube amplifiers, computers, etc. are going to be replaced by solid-state amplifiers, computers, etc. but not 100% replaced as we can still find vacuum tube amplifiers everywhere but vacuum tube computers are already very rare.

But if I have to form the reason why vacuum tubes are still used to generate high energy radiations instead of solid-state devices with my own reasoning (although I have very limited background in physics), high speed electrons are only possible if there is some kind of chamber inside. So, common sense tells us that there is a need to include a chamber inside that thing so electrons can move freely instead of flowing through solids that will pose many difficulties.

\$\endgroup\$
17
  • 3
    \$\begingroup\$ How do you know they can't be replaced? What research have you done about the subject? \$\endgroup\$
    – Justme
    Commented Oct 22, 2020 at 6:30
  • 4
    \$\begingroup\$ you basically asked exactly the same way before, and the reasons are mostly the same. In this new question of yours, you don't even show any additional research since that previous question, nor a glimpse of understanding the answers you've gotten. This bodes badly. \$\endgroup\$
    – Marcus Müller
    Commented Oct 22, 2020 at 7:32
  • 2
    \$\begingroup\$ @MohamedObeidallah you even recognized that yourself in a comment to your previous question, where you literally said "Oh, they don't generate high-energy radiation at all". This question is really about the same topic, and you make zero references to your previous question and the things you've learned from the comments and the answer there. Don't know how to help you learn if you don't incorporate the things that you've learned. \$\endgroup\$
    – Marcus Müller
    Commented Oct 22, 2020 at 8:10
  • 2
    \$\begingroup\$ Can you give me a reason why rubber boots don't emit bremsstrahlung? There's no high-speed electrons. I mean, why should they? This question makes no sense! \$\endgroup\$
    – Marcus Müller
    Commented Oct 22, 2020 at 8:12
  • 3
    \$\begingroup\$ yes, that sounds correct, and also, this sounds like it should be part of your question text, not written in a comment after we asked you a million times to explain why you think solid state devices are capable of doing that. Please edit your question to explain your full train of thought. \$\endgroup\$
    – Marcus Müller
    Commented Oct 22, 2020 at 8:32

1 Answer 1

Reset to default
1
\$\begingroup\$

Semiconductors or actually the electrons which have a role in the conducting of the current operate within so narrow energy level variation range that no emitted photons can get high enough energy to be in X-ray wavelength range when an electron falls to lower energy state. To get energetic enough transitions we should have a solid semiconductor material with hundreds of times wider gap between the valence band and the conduction band than in our current materials.

To generate X-rays with DC in solid material needs probably a new principle or the ordinary long wavelength radiation maybe could be converted to X-rays. I am not a physicist so I have no idea how for ex. the conversion laser could work in X-rays because ordinary mirrors at least are useless.

\$\endgroup\$
5
  • \$\begingroup\$ So, at least large gaps are needed to separate the conduction and valence band so the electrons can move much more freely. Then, high energy photons such as X-ray and beyond can be easily generated. Thus, adding some kind of cavity is necessary even when we are using solid-state devices to generate such radiations. Like this amptek.com/internal-products/…. Is that correct? \$\endgroup\$
    – SnoopyKid
    Commented Oct 22, 2020 at 10:52
  • 2
    \$\begingroup\$ The pyroelectric X-ray generator IS a new principle, totally different than what happens in LEDs. See this: researchgate.net/publication/… About semiconductors: Diamond is quite a wide gap material that can be a semiconductor. But something much wider is needed. BTW the gap isn't a cavity inside material, it's a zone in the energy state diagram of the material. Read some solid state physics or elementary semiconductor theory in undergraduate academic level. \$\endgroup\$
    – user136077
    Commented Oct 22, 2020 at 11:28
  • \$\begingroup\$ How about this energyeducation.ca/encyclopedia/Conduction_band? Is it possible to combine an insulator with a semiconductor to prevent the issue that semiconductors have when it comes to generating high energy photons? \$\endgroup\$
    – SnoopyKid
    Commented Oct 22, 2020 at 11:30
  • \$\begingroup\$ Sorry, but I am not a scientist, I can connect and burn electronic components and sometimes I succeed to guess right how a circuit works. Your question needs a solid state physics aware scientist to answer. I must be happy with available components. I really have no idea how to calculate what electron state structure become possible by somehow mixing insulator and semiconductor. \$\endgroup\$
    – user136077
    Commented Oct 22, 2020 at 15:10
  • \$\begingroup\$ Nevermind it's okay. Thanks again for your responses! \$\endgroup\$
    – SnoopyKid
    Commented Oct 22, 2020 at 15:15

Not the answer you're looking for? Browse other questions tagged or ask your own question.