Letter of Intent for SPES NUCLEAR MOMENT STUDIES WITH GALILEO R. Lozeva1, C.A. Ur2, D.L. Balabanski2, C. Beck1, G. Benzoni3, D. Curien1, G. Duchene1, J.M. Daugas4 and M. Hass5 1. IPHC, CNRS/IN2P3, Strasbourg, France 2. ELI-NP, Bucharest, Romania 3. INFN Milano, Italy 4. CEA, DAM/DIF, Arpajon, France 5. The Weizmann Institute, Rehovot, Israel

NUCLEAR MOMENT MEASUREMENTS nuclear s.p. structure purity wave function magnetic moment quadrupole moment collective properties nuclear deformation fusion-evaporation ~50% fission (spontaneous/relativistic) ~40% / ~20% fragmentation ~15-30% multi-nucleon transfer and DI ? /(d,p) ~20-30% Spin-orientation (reaction-induced)

Time Differential Perturbed Angular Distribution THE TDPAD TECHNIQUE Isomeric decay R(t) function g-factor: external B field Q: host with E field gradient Time Differential Perturbed Angular Distribution

POSSIBLE CONFIGURATION @ SPES for g-factor measurements using G.GALILEO (4-8 3-cluster detectors) in a horizontal plane around electromagnet (e.g. g-RISING detector configuration) -> 4 detectors @ 18 cm: e: 2% Ebeam~5 MeV/u -> BG -> TA/host sandwich (variable thickness to adjust stopping range) -> coupling to particle detectors (DANTE, TRACE, LuSiA,…) secondary TA host beam dump x B some info from g-RISING (43cm -> e: 2.3%), 1T electro-magnet, ancilary detectors (validation+veto) to reject BG Tandem-ALTO/GANIL 4 Ge coax detectors (10cm -> e: 3.5 %)

POSSIBLE CONFIGURATION @ SPES secondary TA host beam dump x B The GAMIPE setup @ LNL (Hall I) - planar Ge detectors - GASP Ge detectors - pulsed beam: res. 2 ns repetition 200 ns – 6.4 µs G.GALILEO - Ge triple clusters

PHYSICS CASE : p-rich & n-rich neutron-deficient nuclei around 100Sn: 94Pd, 96,97Pd, 98Cd… (but possible to study only with proton-rich beams as 58Ni, 68Ge… >> update: not available @SPES) neutron-rich nuclei around 132Sn: 129,131In, 134,6,8Sn, 134Te… (and many others newly found e.g. in the recent campaigns at in-beam facilities) plenty of isomers in ns-ms range Initial physics goals of this LoI were to study both p-rich and n-rich nuclei, however as the p-rich will not anymore be available, we concentrate on two n-rich regions of key-importance (around Sn and around Ni) as will be shown in the next slide. We also note that the proposed methodology can be applied to any region of the nuclear chart, from light to heavy nuclei, thus if approved one could think of a campaign on moment measurements with many different physics cases. (slide to be flashed) Challenges isomeric structure: p/h configurations on doubly-magic core states, p-n interaction fix/assign spins/parities properties M1 operator: ? quenching @ the two extremes of isospin (100Sn <-> 132Sn) seniority isomers & core excitations, competition between pairing & deformation single/particle <-> collective properties, …

PHYSICS CASE : n-rich only updated neutron-rich nuclei around 68-78Ni: 68- 70Ni,71,2,5Cu, 71,78Zn, 78Ga, 75Ge, 79As… (large landscape of possibilities with high- intensity n-rich beams) neutron-rich nuclei around 132Sn: 129,131In, 134,6,8Sn, 134Te… (and many others newly found e.g. in the recent campaigns at in-beam facilities) plenty of isomers in ns-ms range (slide to be discussed) Challenges isomeric structure: p/h configurations on doubly-magic core states, p-n interaction fix/assign spins/parities odd/even isotopes properties M1 operator: ? quenching/evolution of shell gaps N=82, N=90 (Sn/In,Te); size of N=50 and evolution of N=56 (Ni/Ge,Se); seniority isomers & core excitations, competition between pairing & deformation single/particle <-> collective properties, …

FEASIBILITY @ SPES : n-rich only neutron-rich beams e.g. 125-130In, 132-136Sn, … high-intensity > 105-7/s combined with light-targets e.g. 2H (d,p) (d,t) 9Be targets (+) very clean reactions (+) have spin-alignment / (-) can not go very far combined with 238U: e.g. MNT, DI (-) ? do no know much about the spin-alignment / (+) can go more exotic (+) heavier targets/s => some pre-SPES investigations required ! (-) ? beam pulsing (d,p), (d,t) MULTI-NUCLEON TRANSFER, DEEP-INELASTIC Sn Ni neutron-rich beams e.g. 70Ni, 77Cu, 80Zn, 83Ga, 85Ge, 87As, 89Se… (phase 1: 70,3Cu,73,6Zn,77,81Ga,78-84As) high-intensity > 104-7/s combined with targets e.g. 2H, 9Be can do many ns-ms isomers in 68-70Ni,71,2,5Cu, 71,78Zn, 78Ga, 75Ge, 79As… an example: (phase 1/phase 2) 72Cu(d,p) 73Cu/74Cu(d,p) 75Cu/135Sn(d,p)136Sn s~10 mb @ 240 MeV target thickness: 1-2 mg/cm2, int: 105-7/s eg: 2%, isomeric ratio: 10-15% -> 3x106 ions/week -> 104 g/det/week => g-factor can be measured with <5% uncertainty ! 2x104 delayed g -> ~3.5% 2x105 delayed g ~1% quality/uncertainty in g-factor mearements (real data) Last slide of the presentation: discussion may be done around the reaction types: d,p and mnt/DI to access even more exotic nuclei. The intensities of phase 1 will allow many of the nuclei of interest to be accessed for moment studies, however the advantage of beams and intensities in phase 2 (tables from the web-page of the Spes WS) is obvious and indispensable for the very neutron-rich species.

Thank you

FEASIBILITY @ SPES : p-rich & n-rich FUSION–EVAPORATION neutron-deficient beams e.g. 81Kr, 88Y high-intensity > 105-6/s combined with targets e.g. 50Cr, 40Ca energies 3-5 MeV/u from ALPI re-accelerator (batch mode) beam pulsing is ensured BG problems due to the more intense accompanying radioactive ions (-) not enough p-rich to produce p-rich nuclei (d,p), (d,t) MULTI-NUCLEON TRANSFER, DEEP-INELASTIC neutron-rich beams e.g. 125-130In, 132-133Sn, … high-intensity > 105-6/s combined with light-targets e.g. 2H (d,p) (d,t) 9Be targets (+) have spin-alignment / (-) can not go very far combined with 238U: e.g. MNT, DI (-) ? do no know much about the spin-alignment / (+) can go more exotic => some pre-SPES investigations required ! (-) ? beam pulsing Sn Sn an example: 40Ca(56Ni,2p2n) 94Pd s~6-10 mb @ 190 MeV target thickness: 1-2 mg/cm2, int: 107/s eg: 2%, isomeric ratio: 10-15% -> 3x106 ions/week -> 104 g/det/week => g-factor can be measured with <5% uncertainty ! 2x104 delayed g -> ~3.5% 2x105 delayed g ~1% quality/uncertainty in g-factor mearements (real data) Old slide p-rich and n-rich (can be used in case of a discussion on the initial demand of this LoI)