Task id15500

If a parallel beam of X-rays of wavelength L is allowed to fall on an arbitrarily oriented crystal of any substance, then, generally speaking, intense diffracted beams of rays will not arise. Such beams will appear: 1) if the beam of X-rays consists preferably of continuously distributed wavelengths, and does not represent a single wavelength; 2) if the sample is not a whole crystal, but a powder of small crystals. Please explain.