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Explore the collaborative research on Giant Resonances and neutron skin thickness, employing innovative experimental methods and setups. Investigate the SDR sum-rule, neutron detection, and the physics implications in unstable nuclei.
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GIANT RESONANCES, NEUTRON SKIN • Krasznahorkay, M. Csatlós, J. Gulyás, M. Hunyadi, Z. Máté, • B.M. Nyakó, D. Sohler, L. Zolnai • for the ATOMKI, KVI, RCNP, INFN collaboration Nothing tends so much to the advancement of knowledge as the application of a new instrument. -- Sir Humphrey Davy
History of the collaboration • Postdoctoral position at KVI (AK, 1989,1990) • GR studies with magnetic spectrographs • A split-pole magnetic spectrograph as a present • NWO + OTKA support • Study of HD states in Debrecen, + collaboration also with LMU • Postdoc position at KVI (MH, 2000,2001) • NWO-OTKA (1994-2002, 49 publications) • 2002-2007 + 30 common publications.
Electric Giant Resonances Isoscalar Isovector 1977 1983 Monopole Dipole 1948 1971 1980 Quadrupole
Experimental determination of the neutron-skin thickness neutrons protons
The GDR method Hatáskeresztmetszet számolások a GT és SJ modell alapján
Final state spectra for the 208Pb(, ’) reaction NaI det. Clover det.
Determination of the neutron-skin thickness of 208Pb GDR results 0.12±0.07 fm G.W. Hoffmann et al., Phys. Rev C21 (1980) 1488 0.14±0.04 fm Trzcinska et al., Phys. Rev. Lett.87 (2001) 82501 0.15±0.03
Vibrations in the spin-isospin space: Sum rule for the SDR strength A. Krasznahorkay et al., Phys. Rev. Lett. 82 (1999) 3216.
(p,p) GDR SDR A. Krasznahorkay et al., Phys. Rev. Lett. 82 (1999) 3216.
Experimental methods BBS E=177 MeV =3.2o
Isovector GR’s in unstable nuclei -The physics case • Macroscopic & microscopic info • Neutron skin • SDR sum-rule • Ex(GTR)-Ex(IAS) • astrophysics e.g. -process • Experimental considerations ((p,n) in inverse kinematics) • High cross sections (~10mb/sr) • Complete kinematics (use FRS) • low-En, no energy loss in target • Neutron detection • aim: 1MeV resolution in Ex • required: 10 En /En= 10 % flight path: 1 m, Timing resolution: 1 ns
The ELENA setup • Type of the scintillator: UPS-89 = NE102A • Syze of the scintillator: 10x45x1000 mm • PMTs: XP2262 + active dividers
Conclusions • GR studies in stable beams • GR studies in RIB’s • Challenges for the detectors