Dear Subhajit Chakraborty ,

you will never get a specific value because the energy spectrum of the photons emerging from the focus of an x-ray tube is a very broad one ranging from roughly about 20 keV up to the keV value, which is identical to the kV preset of the tube voltage. They are in the range of up to about 30 to 40kV for mammography, in the range of about 50 to 60kV for x-raying of arms and legs and between roughly 80 and 140kV for whole body CT. All the kV values depend on the thickness of the part of the body being examined.

A mean value of the energy spectrum also depends on the depth inside the body part, which your are interested in.

For the primary radiation just at the surface of the body the mean photon energy is roughly about 2/3 to 3/4 of the preset kV value in keV; it depends on the inherent and additional filtration and the take-off angle of the x-ray target.

You may share for what kind of purpose(s) you need such number(s).

Maybe, we can help you...

Final remark: sorry, you asked for wavelengths;

the relation between wavelength lambda and x-ray photon energy E is:

E * lambda = h*c; in numbers: E[eV] * lambda[A] = 12398

You may convert by yourself, if necessary...

Best regards

G.M.

That's great. Too informative response.

Thank you so much.

This will help me a lot.

Thanks again.