Which method uses zinc sulphide crystal for detection?
Alpha particles produce intense localized scintillations because of high linear energy transfer. Zinc sulphide doped with silver activated phosphor converts alpha kinetic energy into visible light flashes when alpha strikes crystal lattice raising electrons to excited states. These flashes are counted under microscope or photomultiplier in spinthariscope. Beta and gamma radiations cause weak luminescence not efficiently captured by ZnS, and require organic or sodium iodide crystals. X-ray detection uses different phosphors. Hence zinc sulphide scintillation screen has been historically specifi
Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.
