Post on 26-Jan-2016
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Kerstin Sonnabend, IKP, TU Darmstadt S-DALINAC: Nuclear Structure Physics
Nuclear Structure Physics at the Darmstadt superconducting electron linear accelerator
S-DALINAC
N. Pietralla and K. Sonnabendfor the SFB 634
Workshop on European Small-Scale Accelerator Facilities
Aghios Nikolaos, Crete, Greece
September 7th to 8th, 2007
supported by the DFG under grant No. SFB 634
Kerstin Sonnabend, IKP, TU Darmstadt S-DALINAC: Nuclear Structure Physics
Accelerator hall of the S-DALINAC
– electron energies from 2 to 130 MeV available– cw and pulsed beam operation possible– source for polarized electron beams under construction
HIPS
Kerstin Sonnabend, IKP, TU Darmstadt S-DALINAC: Nuclear Structure Physics
HIPS – High-intensity photon setup
– continuous-energy bremsstrahlung
– 2 MeV ≤ Emax ≤ 11 MeV
– photon intensities: 106 keV-1s-1cm-2
– two target positions for simultanuous (,‘) experiments
– up to four HPGe detectors partly passively shielded partly segmented
Kerstin Sonnabend, IKP, TU Darmstadt S-DALINAC: Nuclear Structure Physics
HIPS – High-intensity photon setup
11B
11B
1-
1-
Kerstin Sonnabend, IKP, TU Darmstadt S-DALINAC: Nuclear Structure Physics
Experimental hall of the S-DALINAC
NEPTUN – High-resolution tagger
taggersystem
Kerstin Sonnabend, IKP, TU Darmstadt S-DALINAC: Nuclear Structure Physics
NEPTUN – High-resolution tagger
Energy range: 6 MeV ≤ E ≤ 20 MeV
Energy resolution:E = 25 keV @ 10 MeV
Energy window: ≈ 3 MeV
Photon intensity: ≈ 104 keV-1s-1
1 m
Photon energy: E = Ei - Ee
focal plane
radiator
magnet
coincidence
experiment
Kerstin Sonnabend, IKP, TU Darmstadt S-DALINAC: Nuclear Structure Physics
NEPTUN – High-resolution tagger
– untagged photon spectrum
– tagged photon spectrum: E = 10 MeV
– simulation of detector response
Kerstin Sonnabend, IKP, TU Darmstadt S-DALINAC: Nuclear Structure Physics
Experimental hall of the S-DALINAC
LINTOTT – High-resolution spectrometer
LINTOTT
Kerstin Sonnabend, IKP, TU Darmstadt S-DALINAC: Nuclear Structure Physics
LINTOTT – High-resolution spectrometer
scatteringchamber
electrons
energy range:18 MeV ≤ Ee ≤ 120 MeV
scatteredelectrons
deflection angle:169.6º ± 0.1º
energy resolution:E/E ≈ 1 10-4
data rate: up to 100 kHz
detectorsystem
detector system:96 silicon strip detectors
Kerstin Sonnabend, IKP, TU Darmstadt S-DALINAC: Nuclear Structure Physics
LINTOTT – High-resolution spectrometer
94Mo(e,e’)
excitation energy / MeV0 1 2 3 4
coun
ts /
C
0.0
0.1
0.2
O.Burda et al., PRL 99 (2007) 092503
– very good energy resolution (see ground-state)
– ideal method to study one-phonon modes
– far-off yrast spectroscopy possible (up to observed)
€
214+
symmetric octupole phonon
€
31−
symmetric quadrupole phonon
€
21+
mixed-symmetry state
€
23+
Kerstin Sonnabend, IKP, TU Darmstadt S-DALINAC: Nuclear Structure Physics
LINTOTT – High-resolution spectrometer
Planned experimental program
Determination of excitation strengths and form factorsof low-spin excitations
– mixed-symmetry states in mass regions A = 90 and 130
– intrinsic structures in shape-phase transitional nuclei
– investigation of new electric dipole modes (besides IVGDR)
form factors of PDR states in N = 82 isotones and 208Pb
find evidence for purely transverse E1 mode below GDR
Kerstin Sonnabend, IKP, TU Darmstadt S-DALINAC: Nuclear Structure Physics
Experimental hall of the S-DALINAC
QCLAM – Large acceptance spectrometer
QCLAM
Kerstin Sonnabend, IKP, TU Darmstadt S-DALINAC: Nuclear Structure Physics
QCLAM – Large-acceptance spectrometer
Planned experimental program
– (e,e‘x) coincidence experiments for the investigation of new electric dipole modes (besides IVGDR)
form factors of PDR states in N = 82 isotones and 208Pb
find evidence for purely transverse E1 mode below GDR
– excitation and decay of ISGDR in 58Ni, 90Zr, 140Ce, and 208Pb
– experiments on -cluster states in light N = Z nuclei
– (e,e‘) coincidence measurements using Ge detectors
Kerstin Sonnabend, IKP, TU Darmstadt S-DALINAC: Nuclear Structure Physics
Experimental hall of the S-DALINAC
QCLAM
LINTOTT
NEPTUN
HIPS