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
Discovery of X-rays and radioactivity
1895 – discovery of X-rays (W. C. Roentgen)
1896 – discovery of radioactivity H. Becquerel (by means of
photographic plate)
(fluorescence, scintillation, photographic plate and latter gas
filled ionization chamber are used for detection)
W.C. Roetgen
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
First X-ray
photograph
Alpha particles were observed using microscope by
means of ZnS scintillation in the original Rutheford
experiment
First energy determination
(Studies of basic properties of radioactive rays )
1905 – W. Bragg, R. Klieman – measurement of alpha range at gas –
different ranges → different energies – discrete spectra
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
Inventor of cloud chamber C.T.R. Wilson and his first photographs of alpha and beta particles
Begining of real spectroscopy
1912-15 - energy determination - Bragg diffraction on crystal planes
Max von Laue, W.H. a W.L. Braggs
Father and son Braggs
Max von Laue
Laue diagram No 5
from 1911 - 13 – beginning of spectroscopy studies
Electron and alpha movement through magnetic field
(alphas needs strong field)
1913 - First focusing beta spectrographs
1914 – Gamma energy measured by crystal diffraction method
1914 – Accuracy of alpha energy measurement ~ 1%
One of first crystal diffraction
spectrometers (detection by
ionization chamber) – F.C. Blake,
W. Duane, Phys Rev 10(1917)624
Beginig of neutron spectroscopy, scintillator detectors
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
Thirties and forties – artificial radioisotopes are accessible (P. and M. Curie,
E. Rutheford), first accelerators
1944 – Curran, Baker invent photomultiplier
1948 – NaI(Tl) scintillation detector R. Höfstadter – high efficiency,
energy determination in wide range spectra, FWHM ~ 7%
much later further materials (BGO, BaF2, plastics …)
R. Höfstadter and his article about NaI(Tl) crystals at Physical Review from the year 1949
Figure of NaI(Tl) signal compared with signal from pulser.
Broad development of classical spectroscopy
(scintillation detectors and magnetic spectrometers)
Example of work in the field of conversion electron spectroscopy
From forties, magnetic spectrograph, photographic method
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
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
Studies of nuclear structure, excited states, transitions …
Semiconductor detectors, development of electronics
Development of multiparametric multichannel analyzers – efficient usage of
scintillation detectors, coincidences, time characteristics, development of electronics
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)
Complex on beam measurements
Splitting to: application (medicine, material research…)
basic research (studies of nuclear structure
and reaction mechanism)
~ 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
1971 – anticompton spectrometer J.Konijn – suppression
of compton background up to one order
Golden age of classical spectrometry, its completion and
development of applications
Present commercial HPGe
detector of PGT company
Complex electronic experiments → high energies, rare phenomena
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 …
Set-up of HPGe detectors
JUROSPHERE
Combination of many types of detectors for different particles
Complex electronic systems, superconductive magnets
„Event by event“, 4π detectors, high energy and
heavy ion experiments (Plastic Ball)
New types of materials PbWO4, …
Plastic Ball at KVI Groningen
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