Superheavy Element Studies Sub-task members: Paul GreenleesJyväskylä Rodi Herzberg, Peter Butler, RDPLiverpool Christophe TheisenCEA Saclay Fritz HessbergerGSI Christelle StödelGANIL Michael SewtzLMU München Krunoslav SuboticINN Vinca

S. Hofmann, Nucl. Phys. News Intl Synthesis & Decay Spectroscopy EURISOL intensities at least 10x lower than stable beams Produce & study neutron-rich nuclei?

What can be done with 132 Sn? X Sn N=82 Study region around end of Dubna chains

Example reactions 132 Sn Cs (t 1/2 = 30 years) → 267 Db* 132 Sn + 132,134,136 Xe → 264,266,268 Rf* 132 Sn Ba → 270 Sg* 132 Sn La → 271 Bh* 132 Sn + 140,142 Ce → 272,274 Hs* 132 Sn Nd → Ds* 90,92 Kr Ta → 271,273 Mt* 90,92 Kr W → 276,278 Ds* 44 Ar Th → 276 Hs* 44 Ar U → 282 Ds*

Egido & Robledo PRL Kr Dy  256 No * E x = 24 MeV High spin states in SHE 48 Ca Pb  256 No * E x = 21 MeV Predicted simultaneous alignment of  i 13/2 and j 15/2 around 30ħ

In-beam spectroscopy - which cases? Already Done Neutron Number Proton Number Potentially doable Feasibility depends on the specifics of each and every case!

Example reactions 92 Kr Dy → 256 No* 132 Sn Xe → Rf* 50 Ca Hg → 254 Fm* 50 Ca Tl → 255 Md* 50 Ca Pb → 258 No* 50 Ca Bi → 259 Lr*

Gamma-ray Spectrometer Dominant channel is constant ~ b fission. This limits Ge rate! Target wheel spokes need beam sweeping High efficiency, granularity and energy resolution (AGATA!) “Conventional” alternative array when AGATA is elsewhere?

Electron Spectrometer   Fission does not readily produce CE   SHE produce more CE than Gamma High (>10%) efficiency up to 0.5 MeV Energy resolution 1 keV to resolve L & M CE Couple to recoil separator and/or  array SAGE

Recoil separator or spectrometer Mass resolution not essential if tagging, but could be useful in certain cases? High transmission efficiency (>40%) & beam suppression (>10 12 ) for all reactions. Momentum acceptance >10% Angular acceptance > ±10° Focal plane size matched to detection system Focal plane system to measure all decays (  p, e-, fission) with high efficiency Flexible DAQ for correlations (triggerless TDR?) Rotating or cooled targets Radioactive targets

Resonance Ionization Spectroscopy Buffer gas cell + optical resonator High repetition rate, high power laser systems PIPS detectors Z & A selective detection? Entrance Foil

Ion mobility measurements Ion mobility is related to ion’s size Need: Ion Mobility Spectrometer Direct mass separation (QMS) or magnet Position sensitive parallel plate trigger counter PIPS detector wheel Build on HV platform to extract 60keV beam out of buffer gas cell and allow subsequent mass analysis in magnetic separator?

Beam Requirements Narrow excitation functions  <1% energy resolution Emittance <5  mm rad (as presently available) Wobbling system in addition to target wheel? Stable beam operation for calibration (10-100pnA) Campaigns of experiments for efficient use of beam time

Required floor space Largely dictated by separator (e.g., SHIP is 12m long) Shielding for electrostatic elements & beam dump Space around target for  -ray & electron spectrometers Space at focal plane for spectrometer, atomic physics & chemistry set-ups 20m x 20m is probably reasonable Room background needs to be low!!

Future work Cross section calculations are needed! Rate of scattered beam particles in target chamber ( 132 Te t 1/2 = 70h)

Future work Cross section calculations are needed! Rate of scattered beam particles in target chamber ( 132 Te t 1/2 = 70h) Design of separator, target chamber, spectrometers, … Shielding of beam dump in separator …

In-beam  -ray spectroscopy Lighter neutron-rich nuclei?

Compound nuclei 48 Ca Sn  172 Yb*