Spectroscopy and lifetime measurements at ReA12 Hiro IWASAKI (NSCL/MSU) 7/12/2014Recoil Separator for ReA12 workshop1

Example : neutron-rich Ni isotopes 7/12/2014Recoil Separator for ReA12 workshop2 spectroscopy of band structure built upon the 0 2,3 + states Y.Tsunoda et al., Phys. Rev.C 89 (2014) (R) S.Suchyta et al., PRC89(14) (R) 68 Ni Low-energy reactions Studies beyond the 2 + states

Example2 : 3NF effects in n-rich O and Ca 7/12/2014Recoil Separator for ReA12 workshop3 transition rates and comparison to theory G.Hagen et al., PRL109(12) high-energy gamma-ray detection measurements of short lifetime (  ≤1ps) A.Gade, R.V.F.Janssens et al., PRC74(06)021302(R)

Recoil Distance Method 7/12/2014Recoil Separator for ReA12 workshop4 H. Iwasaki - Slide 4 model-independent determination of transition rates Advantages Disadvantages ∙ use of various reactions ∙ access to higher-lying states ∙ access to shorter (<1ps) lifetimes ∙ needs to measure at several distances ∙ broad charge-state distributions ∙ feeding effects (need g-g coincidence) Lifetime a sensitive probe for nuclear structure … B(E2), B(M1)

Recoil Separator for ReA12 workshop57/12/2014 Example : 128 Xe + Fe at 525MeV Detailed structure information is to be studied by (multiple) Coulomb excitation and lifetime measurements. Higher beam energies (>5AMeV) increase cross sections (particularly for higher-lying states) and allow use of thick targets. W.Rother et al., NIMA654(11)196 2mg/cm2 Fe target 4mg/cm2 Nb degrader Inverse-kinematics Coulomb excitation + RDDS lifetime measurements  gr =10 o With measured lifetime, GOSIA calculations are possible to determine Q(2 + )

Energy dependence of Coulex 7/12/2014Recoil Separator for ReA12 workshop6 HIE-ISOLDE the scientific opportunities CERN (2007) Multiple (safe and unsafe) Coulex : best at ReA12 CC (ECIS97) calculations for Sn+Pb 10 ReA12 FRIB

Excitation beyond the first 2 + state 7/12/2014Recoil Separator for ReA12 workshop7 Examples : 76 Kr + Pb at 4.4AMeV 132 Sn + Pb at 50AMeV (Ec=10AMeV) (  gr=6.5deg) E.Cle’ment et al., PRC56(2007) Need to cover large scattering angles

Grazing angles at 12AMeV 7/12/2014Recoil Separator for ReA12 workshop8 Examples : Ein = 12AMeV 32 Mg + Pb Fe + Pb Sn + Pb Mg + Fe Fe + Fe Sn + Fe 21 6  gr (CM) [degrees]  gr (Lab) [degrees] Ec =10AMeV Ec = 5AMeV

Charge States … 7/12/2014Recoil Separator for ReA12 workshop9 Example : 48 Ca (5AMeV) + Au/C N.K.Skobelev, ISSN IET2008, 51, p351

Beam 7/12/2014Recoil Separator for ReA12 workshop10 Lifetime setup at ReA12 ReA12 38cm cm Primary Secondary  (  ) Magic angle Angle for lifetime  Z 150AMeV 90AMeV 0.41(1.10) 67 deg < 40 deg (  =10%) 13cm ReA12 12AMeV 0.16(1.01) 80 deg < 50 deg 6cm (can use both rings)

Requirements … 7/12/2014Recoil Separator for ReA12 workshop11 H. Iwasaki - Slide 11 Angle Energy PID others ∙ (Multi) Coulex 0-20 degrees 5-10AMeV A and Z (and Q) rates at FP (0-10 degrees for inv. with medium mass target) ∙ Lifetime larger acceptance for different Q *) Rotatable or ~8 degrees acc. A and Z (and Q) A >= 100 dE>=10% *) tracking information for recoils (x,y,x’y’,  ) is required with 1mm,1mrad,1% precisions for Doppler-shift corrections and possible alignment measurements

Summary 7/12/2014Recoil Separator for ReA12 workshop12 H. Iwasaki - Slide 12 ∙ Spectroscopy and lifetime measurements at ReA12 are discussed. ∙ Deep inelastic scattering and multiple Coulomb excitation are useful reactions at ReA12 to access medium/high-spin states of neutron-rich nuclei and should be used in detailed spectroscopy. ∙ Requirements for experiment setup, particularly for spectrometer to be prepared at ReA12, are discussed.

Thank you 7/12/2014Recoil Separator for ReA12 workshop13

Backup 7/12/2014Recoil Separator for ReA12 workshop14

Spectroscopy and lifetime measurements at ReA12 7/12/2014Recoil Separator for ReA12 workshop15 New (old) reactions can be used with RIB - Deep inelastic - Multi Coulex to access medium-spin states of n-rich nuclei

GRETINA at NSCL 7/12/2014Recoil Separator for ReA12 workshop16