Neutron Scattering Questions from the class

Q1: Can we perform neutron scattering experiment instead of x-ray scattering
experiment? (i.e., Can the X-ray diffraction method be replaced by neutron
diffraction method? If yes, why do need the two?)

Q2: Photon and neutron scattering are heavily used. How about electrons?

Q3: Neutron Energies and wavelengths
(a) The neutrons are produced from high energy accelerators or neutron
reactions, and their energy at that time is very high. So, the neutrons then enter  a moderator in order to reduce their energy through the collisions. How is neutron energy controlled by the temperature of the moderator?

(b) What neutron energy is desirable?

(c) In page (17), how can we prove the mathematical equation of the probe
wavelength?

(d) I wonder about the effect of the neutrons on the nucleus of the sample. In the production of neutrons, they have to be cooled so as to not be too quick, but in general is their effect on the
sample simply ignored? 

Q4: What is the difference between the scattering process and diffraction process?

Q5: What are the driving factors for either coherent or incoherent neutron
scattering will take place in sample? How we can control experimentally whether we do coherent or incoherent scattering?

Q6: In Fig. 4, we see neutron scattering from a fixed point. I'm not quite sure I understand why, from the physics point of view, the scattering of the plane wave becomes an isotropic circular wave.

Q7. Most of the methods suggest Monochromatic neutrons should be used. Is
there any method to use multi wavelength neutrons like Laue method in XRD?. 

Q8. In the powder diffraction at a spallation source (page 17) the interplaner
spacing (d) has a range of values for each detector bank? How is that
possible if the vector representing sample-detector bank distance doesn't change. 

Q9. In a SANS spectrometer, is it possible to use crystal monochromators
instead of mechanical velocity selectors to monochromatize the neutron beam?

Q10. In small angle neutron scattering spectroscopy, the gravity focuser is used to account the fact that neutron falls under gravity. Why cant the entire setup be fixed vertically to avoid the
trajectory path due to gravity? 

Q11. In his discussion on surface scattering, Pynn mentions a critical angle of
incidence that is proportional to the coherent scattering length density of
the material and the neutron wavelength. Is there a general expression for this
angle and, if so, how is it determined? 

Q12. Furthermore, does neutron surface scattering obey the Fresnel equations as Pynn suggests?