History of nuclear spectroscopy

1) First determination of radioactive ray energy – discovery and first studies of radioactive radiation nature

2) Beginning of spectroscopy („age of magnetic spectroscopes, diffraction spectroscopes …“) beginning of radiation nature and nuclear structure studies

3) Start of scintillation detectors and electronic (multichannel analyzers – beginning of classical nuclear spectroscopy golden age, study of many nuclear excited states and transitions

4) Start of semiconductor detectors, intensive development of electronics – golden age of classical nuclear spectroscopy – extensive catalogues of excited nuclear states and transitions for theory tests, broad advancement of nuclear spectrometry applications

5) Complicated 4pi detector setups, complicated multicoincidences, „event by event“ analysis – transition to high energies, studies of very rare and hyperfine effects (giant resonances, superdeformed states, high energy nuclear physics …). Wide development of nuclear spectrometry applications. Completion of classical nuclear spectrometry

1895 – discovery of X-rays (W. C. Roentgen)

1896 – discovery of radioactivity H. Becquerel (by means of photographic plate)

1900 – identification of alpha, beta and gamma rays (E. Rutherford, P. Villard …)1908 – gas filled detectors (E. Rutheford, Geiger)

Proportional counters – energy determination using full stopping of charged particle (from particle range)

Gamma rays – photoeffect and stopping of photoelectron

W.C. Roetgen

First X-rayphotograph

(fluorescence, scintillation, photographic plate and latter gas filled ionization chamber are used for detection)

Alpha particles were observed using microscope by means of ZnS scintillation in the original Rutheford experiment

Discovery of X-rays and radioactivity

1906 -11 - O. Hahn, L. Meytner – beta absorption at material → is not exponential → not only one energy, (incorrect assumption of exponential decreasing of monoenergetic electron beam intensity) O. Hahn, O. von Bayer - magnetic field usage + photographic plate → first magnetic spectrograph of electrons → complicated spectrum

1914 - James Chadwick beta spectrum is also continuous - definitely confirmed by calorimetrical measurements of C.D. Ellis and W. Wooster in the year 1927

1911 - Wilson cloud chamber ( C.T.R. Wilson) – energy from trace length

1905 – W. Bragg, R. Klieman – measurement of alpha range at gas – different ranges → different energies – discrete spectra

Inventor of cloud chamber C.T.R. Wilson and his first photographs of alpha and beta particles

First energy determination(Studies of basic properties of radioactive rays )

from 1911 - 13 – beginning of spectroscopy studies

Electron and alpha movement through magnetic field (alphas needs strong field)

1913 - First focusing beta spectrographs1914 – Gamma energy measured by crystal diffraction method1914 – Accuracy of alpha energy measurement ~ 1%

1912-15 - energy determination - Bragg diffraction on crystal planes Max von Laue, W.H. a W.L. Braggs

Father and son BraggsMax von Laue Laue diagram No 5

One of first crystal diffraction spectrometers (detection by ionization chamber) – F.C. Blake, W. Duane, Phys Rev 10(1917)624

Begining of real spectroscopy

Thirties and forties – artificial radioisotopes are accessible (P. and M. Curie, E. Rutheford), first accelerators

1948 – NaI(Tl) scintillation detector R. Höfstadter – high efficiency, energy determination in wide range spectra, FWHM ~ 7% much later further materials (BGO, BaF2, plastics …)

1930 – 1932 discovery of neutrons by W. Bothe and H. Becker (bombardment of Be, B or Li by alpha particles). J. Chadwick - neutral particle with mass near to proton - neutron. Detection by means of reactions, energy determination by the help of refracted proton

R. Höfstadter and his article about NaI(Tl) crystals at Physical Review from the year 1949Figure of NaI(Tl) signal compared with signal from pulser.

Beginig of neutron spectroscopy, scintillator detectors

1944 – Curran, Baker invent photomultiplier

Continuation of crystal diffraction spectrometers: (resolution – for 100 keV is FWHM ~ 1 eV very low efficiency) very accurate measurements of very intensive lines – calibration standards

Parallel development - better magnetic spectrometers of electrons (better energy resolution than NaI(Tl)) gamma transitions – by means of parallel conversion - photoeffect and determination of photoelectron energy disadvantage - electronic singlechannel, small solid angles,a higher energies → low conversion coefficients

- electrostatic spectrometers

Example of work in the field of conversion electron spectroscopy From forties, magnetic spectrograph, photographic method

Broad development of classical spectroscopy(scintillation detectors and magnetic spectrometers)

Studies of nuclear structure, excited states, transitions …

1960 – Semiconductor Ge(Li) detectors, resolution FWHM = 5 keV → 2 keV (very small energy needed for production of electron hole pair ~ 3 eV) later also Si(Li)

~ 1970 – HPGe – continual temperature of liquid nitrogen is not needed, better resolution and efficiency, smaller noise 1983 – USA abandoned of commercial production of Ge(Li) detectors

Complex on beam measurements

Splitting to: application (medicine, material research…) basic research (studies of nuclear structure and reaction mechanism)

1971 – anticompton spectrometer J.Konijn – suppression of compton background up to one order

Development of multiparametric multichannel analyzers – efficient usage ofscintillation detectors, coincidences, time characteristics, development of electronics

Present commercial HPGe detector of PGT company

Semiconductor detectors, development of electronics

Golden age of classical spectrometry, its completion and development of applications

The eighties and nineties – complex set-ups of scintillation detectors: study of nuclear structure – crystal sphere medical applications – PET chambers

later combination of HPGe (anticompton) and scintillator for gamma rays and „miniorange“ spectrometers for electrons

plastic scintillator „sandwich“ – identification of diferent charged particles

(Nordball, Crystalball, Plasticball …

Complex electronic systems, superconductive magnets

Combination of many types of detectors for different particles

New types of materials PbWO4, … Enable: Study of phenomena with very small probability, high multiplicities, complex coincidences, high energies … nuclear structure - superdeformed states, giant resonances, very accurate spectrometry – search of neutrino mass

Set-up of HPGe detectors JUROSPHERE

„Event by event“, 4π detectors, high energy and heavy ion experiments (Plastic Ball)

Complex electronic experiments → high energies, rare phenomena

Plastic Ball at KVI Groningen