exploring the drip lines: where are the proton and neutron drip lines exotic decay modes: - two-proton radioactivity - -delayed multi-particle emission Bertram Blank for the « Limits » sub-task (if there is…)
the region around 100 Sn: predicted rates (200 A): direct: Sn: 6.8 * 10 6 pps Sn: 1.5 * 10 3 pps Sn: 1.1 * pps second fragmentation of 104 Sn (EPAX2): Sn:8.8 * 10 0 pps Sn: 4.4 * pps - 98 Sn: 3.9 * pps Drip line: 95,96 Sn Difficult to reach…. FAIR?
the region around 132 Sn: predicted rates (200 A): direct: Sn: 3.0 * pps In: 5.9 * pps Cd: 1.2 * 10 3 pps Ag: 5.1 * pps second fragmentation of 132 Sn (COFRA): In: 3.8 * 10 8 pps Cd: 4.6 * 10 6 pps Ag: 7.6 * 10 4 pps (last known 127 Ag) Pd: 3.0 * 10 2 pps (last known 123 Pd) Rh: 2.5 * 10 0 pps (last known 121 Rh) Ru: 1.0 * pps (last known 118 Ru) Tc: 3.3 * pps = 3 ppd ( 115 Tc) Drip line (ETFSI): 134 Tc, 118 Kr(N=82)
Can we reach the drip line in the calcium region? Can we compete with 64 Ni or 86 Kr fragmentation? Predicted rates: 70 Ni: 3.0 * 10 5 pps 94 Kr: 2.4 * 10 8 pps 96 Kr:2.9 * 10 6 pps
production of isotopes below 132 Sn - half-life measurements - decay studies (e.g. neutron emission probability) scan the neutron drip line in the calcium region - half-life measurements - test of mass models via 1n or 2n separation energy fragmentation of 132 Sn, 94 Kr, 104 Sn etc to understand fragmentation process of n-rich and p-rich isotopes
Two-proton emitter with even Z
Simultanous emission: three-body decay A~50 region: half-lives long enough due to Coulomb barrier 2 He radioactivity 45 Fe, 48 Ni, 54 Zn, ?… Sequential emission: -2p decays of 22 Al, 26 P, 31 Ar,… Sequential emission: very light nuclei with broad states
45 Fe 54 Zn 48 Ni
New candidates for the future: 59 Ge 62,63 Se 66,67 Kr 70,71 Sr 74,75 Zr …. What can we learn from two-proton radioactivity: masses of nuclei beyond drip line pairing in nuclei sequence of single-particle levels deformation tunneling process BUT: Is this really a physics topic for an ISOL facility? short half-lives long extraction times secondary fragmentation very far from stability
known cases: 22 Al, 23 Si, 26 P, 27 S, 31 Ar, 35 Ca, 39 Ti, 43 Cr, 50 Ni studied cases: 22 Al (a little), 31 Ar (raisonably well) other cases (from the IAS): 22 Si, 42 Cr, 46,47 Fe, 49,50,51 Ni, 55 Zn, 59 Ge, 63 Se, 67 Kr, 71 Sr…. setup: 8 charged-particle detector:
Study of neutron-neutron correlation advantage: no Coulomb barrier no disturbance of correlation cases: 11 Li (4%), 17 B (11%), 17 C (7%), 30,31 Na (1%), 32,33 Na (10%) other cases? cases: 11 Li (3n), 17 B (3n, 4n) other cases? setup: high-granularity neutron detector
search for low-lying resonances in 26,27,28 O 2p knock-out from 28,29,30 Ne isotopes present detectors: - neutron efficiency: 10% for 1n - 26 O is feasible today ( Ne / s) needs: - increased neutron detection efficiency - sweeper magnet to detect heavy ejectile 24 O 1p knock-out to study neutron bound and unbound states in 27,28,29 F needs: - increased neutron detection efficiency - sweeper magnet to detect heavy ejectile 24 O - high-efficiency -ray detection