# How do ionizing and non-ionizing radiation interact with each other?

Given an ionizing radiation $$X$$ and given non-ionizing radiation $$Y$$, how does this radiation 2 interact with each other?

For example I have X-rays (ionizing radiations) and Microwaves (non-ionizing radiations), I want to understand if there are models that explain how they can interact and what is needed for these 2 radiation classes to interact with each other?

What is the common ground?

• Please see the revision to my answer concerning the term "interaction". – Bob D Jul 9 at 17:43

The categories of ionizing and non-ionizing aren't particularly relevant here. They refer to whether or not the radiation can ionize atoms, which aren't present in your scenario. Microwaves and x-rays do not actually have qualitatively different properties from one another, in and of themselves.

Classically, microwaves and x-rays are electromagnetic waves, and Maxwell's equations are linear, so electromagnetic waves don't interact at all. In most real-world contexts, that's basically the whole story.

Quantum-mechanically, there is photon-photon scattering. Note that a scattering between a microwave photon and an x-ray photon can be made into a symmetric scattering problem by switching into the center of mass frame.

Extending this to all types of radiation is much too broad a question for this site. That would essentially mean giving you an entire course in quantum field theory.

• Well... I still gave you thumbs-up. But not technically zero interaction. x-rays and microwaves are both photons. The first interaction is a 4-vertex one, which is extremely weak. For normal purposes you can certainly ignore it. Even for most exotic purposes you can ignore it. I suppose there are probably experiments that could probe it but I can't come up with one just off hand. – puppetsock Jul 9 at 13:36
• @puppetsock: My answer doesn't say there's zero interaction. Your comment refers to quantum effects, which are discussed in the third paragraph of my answer. – Ben Crowell Jul 9 at 17:08

When electromagnetic waves of any nature pass or meet one another I believe there is the potential for constructive and destructive interference. While this is technically not an "interaction" between waves, which @Ben Crowell pointed out has a specific meaning with respect to electromagnetic waves, I assumed you used the term "interaction" as generally defined in the dictionary being "mutual or reciprocal action or influence" (Webster). If that's not what you meant, please let me know.

Once they pass they generally resume their original form in the absence of any dispersive medium. I would think that the degree of potential interference would depend on how similar the wavelengths are, the closer they are the greater the degree. To that extent, I wouldn't think microwave and x-rays, far apart in wavelength, would involve much if any interference.

That being said, I think of greater interest is how different types of electromagnetic waves interact with matter, particularly regarding ionizing vs non ionizing radiation and human tissue. For a good overview on the interaction of electromagnetic radiation and matter, I recommend you check out the following link:

http://hyperphysics.phy-astr.gsu.edu/hbase/mod3.html

Hope this helps.

• Linear wave interference isn't an interaction, it's a lack of an interaction. An interaction would be a deviation from linearity. – Ben Crowell Jul 9 at 17:10
• @BenCrowell I admit I was not aware that the term "interaction" had a specific meaning in electromagnetism. But I never used the term "interaction" in my answer. I assumed the OP when asking the question had in mind the general dictionary definition, "mutual or reciprocal action or influence" (Webster). Anyway I have revised my answer to clarify it. Thanks for your input. – Bob D Jul 9 at 17:42