L4 X-Rays

X-Rays 1
A. 25keV−250keV
B. 25 000V
C. Thermionic emission

X-Rays 2
A. 3
B. The background tail stretches twice the length along the frequency axis.

X-Rays 3
A. Photoelectric effect

X-Rays 4
A. The Compton effect is the scattering of a photon off an electron, whereas in the photoelectric effect the photon is absorbed when the electron is freed.

X-Rays 5
A. To reduce the intensity of the lower energy X-rays which tend to scatter more

X-Rays 6
A. Because they have their origin in atomic electron energy changes, whereas gammas are due to nuclear energy changes
B. The source of X-rays can be turned on and off, whereas the gamma source is always on.

X-Rays 7
A. 3, 5, 7

X-Rays 8
A. The grid may be made of vertical long, thin lead strips along the X and Y directions, with the width of the strips upright rather than flat. The lead strips can absorb some of the scattered X-rays which are passing through the grid at a shallow angle, rather than those which travel in a direct line from the source to the film.

X-Rays 9
A. barium sulfate

X-Rays 10
A. power/area W^m−2
B. 1/(distance needed to reduce the intensity to 1/e of original level). m^-1
C. 2 cm^-1