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the INFN Italy EXOTIC group Milano, Napoli, Padova, NIPNE Romania, Crakow Poland. Presented by C.Signorini Dept. of Physics and Astronomy Padova (Italy): University and INFN. STUDIES OF Dynamics of the interaction ad the Coulomb barrier induced by light loosely bound
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the INFN Italy EXOTIC group Milano, Napoli, Padova, NIPNE Romania, Crakow Poland. Presented by C.Signorini Dept. of Physics and Astronomy Padova (Italy): University and INFN STUDIES OF Dynamics of the interaction ad the Coulomb barrier induced by light loosely bound Radioactive Ion Beams produced at LNL Tandem Van de Graaff (ITALY) 17F >10^5 Hz 7Be >10^4 Hz 8B >10^3 Hz PRESENTS:→ →
Scattering of 17O by 58Ni at Coulomb barrier energies 1 – (new) Utilization Silicon Detectors with ASIC electronics Large reduction of electronics channels 2 – The physics case Interaction of loosely bound-radioactive nuclei at the Coulomb barrier. Its role played in the reaction cross section Comparison between the reaction cross sections induced by loosely bound (Radioactive Nuclei) and well bound (stable)
Problematic with RIB:projectiles LOOSELY or WELL BOUND Ni, Zn TARGETS LOOSELY BOUND ~ REACTION CROSS SECTION WELL BOUND +17F ~ BOMBARDING ENERGY
Si double sided, 2 mm strip, 32x32 strips, 64x64 mm2, 300 micron thick by MICRON+ two (slow, fast) commercial ASIC chips+home made 12bits multisampling ADC8xSAMPLING AT 50MhZ EXPER. SET UP AND PHYSICS Reaction cross section with170 stable well bound Sn= 4.1 MeV to be compared with 17F unstable loosely bound Sp=0.6MeV Mirror nuclei identical nuclear structure!
ASICS CHIPS ARCHITECTURE ONE CHIP FOR 32 CHANNELS !!!!
OHMIC SIDE JUNCTION SIDE 40m a→→ Si detector 300 m
IN BEAM EXPERIMENTAL SET UP 17O BEAM DIRECTION 2 DETECTORS
208Pb 58Ni 17O SCATT. SPECTRA AT 82°, 58Ni+208Pb mixed target Resolution DE/E ≈ 1.2 %
Reaction cross sections vs. projectile energy in reduced scales. Target 58Ni Loosely bound: 8B Sp = 0.1375 MeV, 17F Sp = 0.600 MeVWell bound: 17O Sn = 4.134 MeV , 16O Sα = 7.162 MeV 17O 17F 8B 16O
Comparison of reaction cross sections for loosely bound and well bound projectiles via different sreact(Ecm)scaling approaches y (sreact), x(Ecm) axis Scaled ALSO for different Coulomb Barrier widths y (s react.), x(Ecm) axis Scaled for different Coulomb Barrier and Radii
CONCLUSIONS 1 – The utilization of commercial ASIC chips reduces succesfully the number of channels of around a factor >10 ! 2 – Energy resolution ~85 keV for a, DE/E ≈ 1.2% in beam,with 50 MeV 17O 3 – 17O well bound scattering has reaction cross sections not smaller than the similar loosely bound projectile 17F . WHY ???