The body of methods for studying atomic nuclei by the radiation that accompanies nuclear transformations and the transitions of nuclei from one state to another. Measurement of the energy, the intensity, the angular distribution and the polarisation of the radiations emitted by a nucleus either in the course of radioactive decay (α- and β-spectroscopy), or in a transition of the nucleus from an excited state to a less excited one (γ-spectroscopy), or in nuclear reactions (direct nuclear reactions, reactions of Coulomb excitation of the nucleus and resonance reactions) gives information about the spectrum of nuclear states — energies, spins, parities, isotopic spins and other quantum characteristics. Neutron spectroscopy holds a special place.
The arsenal of technical means of modern nuclear spectroscopy is varied. It includes magnetic spectrometers for measuring the energies of charged particles, crystal-diffraction spectrometers for measuring the energies of γ-radiation, and various particle detectors that make it possible to record particles and γ-quanta and to measure their energy from the effects of the interaction of fast particles with the atoms of a substance (excitation and ionisation of atoms). Among instruments of this type solid-state detectors have gained great importance (Scintillation counter, Semiconductor detector); they combine good energy resolution (~1—10%) with a high “light-gathering power” (the fraction of the radiation that is effectively used), which in some instruments reaches values close to 1.
The appearance of semiconductor detectors and the development of accelerator technology (Charged-particle accelerators), together with the use of computers (for accumulating and processing experimental data and for controlling the experiment), have given rise to automated measuring complexes that make it possible to obtain large volumes of systematised precision information about the properties of nuclei. The methods of nuclear spectroscopy are used in practically all nuclear research, and beyond physics as well — in biology, chemistry, medicine and engineering; for example, activation analysis relies on data about the decay schemes of radioactive nuclei; the Mössbauer effect, originally used in nuclear spectroscopy as a method of measuring the lifetimes of excited states of nuclei, is applied to the study of the electronic structure of solids, the structure of molecules and more. Data from nuclear spectroscopy are also needed in chemical, biological and other research by isotopic tracer methods.
The arsenal of technical means of modern nuclear spectroscopy is varied. It includes magnetic spectrometers for measuring the energies of charged particles, crystal-diffraction spectrometers for measuring the energies of γ-radiation, and various particle detectors that make it possible to record particles and γ-quanta and to measure their energy from the effects of the interaction of fast particles with the atoms of a substance (excitation and ionisation of atoms). Among instruments of this type solid-state detectors have gained great importance (Scintillation counter, Semiconductor detector); they combine good energy resolution (~1—10%) with a high “light-gathering power” (the fraction of the radiation that is effectively used), which in some instruments reaches values close to 1.
The appearance of semiconductor detectors and the development of accelerator technology (Charged-particle accelerators), together with the use of computers (for accumulating and processing experimental data and for controlling the experiment), have given rise to automated measuring complexes that make it possible to obtain large volumes of systematised precision information about the properties of nuclei. The methods of nuclear spectroscopy are used in practically all nuclear research, and beyond physics as well — in biology, chemistry, medicine and engineering; for example, activation analysis relies on data about the decay schemes of radioactive nuclei; the Mössbauer effect, originally used in nuclear spectroscopy as a method of measuring the lifetimes of excited states of nuclei, is applied to the study of the electronic structure of solids, the structure of molecules and more. Data from nuclear spectroscopy are also needed in chemical, biological and other research by isotopic tracer methods.