  We theoretically investigate a scheme for generations of single hard X-ray
pulses of controllable duration in the range of 1 ns - 100 ns from a
radioactive M\"ossbauer source. The scheme uses a magnetically perturbed
$^{57}$FeBO$_3$ crystal illuminated with recoilless 14.4 keV photons from a
radioisotope $^{57}$Co nuclide. Such compact X-ray source is useful for the
extension of quantum optics to 10 keV energy scale which has been spotlighted
in recent years. So far, experimental achievements are mostly performed in
synchrotron radiation facilities. However, tabletop and portable hard X-ray
sources are still limited for time-resolved measurements and for implementing
coherent controls over nuclear quantum optics systems. The availability of
compact hard X-ray sources may become the engine to apply schemes of quantum
information down to the subatomic scale. We demonstrate that the present method
is versatile and provides an economic solution utilizing a M\"ossbauer source
to perform time-resolved nuclear scattering, to produce suitable pulses for
photon storage and to flexibly generate X-ray single-photon entanglement.
