Spectroscopy of

Super Heavy Nuclei

In-beam Studies

• Experience with gamma and CE studies• Unique set of problems• Main challenge is Fission

In-beam DataS. Eeckhaudt et al., EPJA 26, 226 (2005)

Equipment

• Target (Wheel)

• Prompt Spectrometer capable of high rate

• Separator with large transmission

• Excellent Recoil ID

• DAQ capable of high rate

Gamma Ray spectrometer

• Dominant channel is constant ~0.1 - 1b Fission. This limits Ge rate!

• Target wheel spokes need beam sweeping

• High granularity and large distance to keep individual rates low

• Background from entrance windows etc.– Need windowless system!

Rate calculation basics

• 10 pnA on 500 µg/cm2 at 1 µb = 325 Reactions/h

• At maximum XS ~20 ħ in the system• Fission rates adjusted to match

experimentally observed Ge rates, then scaled

• Two spectrometers: 10% and 50% Efficiency

e.g. EXOGAM or AGATA

Sample calculations

EXOGAM:500 2n 20 1000 650 64 5 10 194 1 500 90000 10 1.00 315 4.9 2.4 60

500 2n 20 100 65 64 5 10 19 11 500 90000 10 1.00 315 4.9 2.4 60

500 2n 20 10 7 64 5 10 2 107 500 90000 10 1.00 315 4.9 2.4 60

500 2n 200 10 65 64 5 10 19 11 500 900000 10 1.00 3147 49.2 24.0 60

AGATA:500 2n 50 100 163 192 5 50 168 1 500 225000 10 2.50 1969 10.3 15.0 60

500 2n 50 10 16.3 192 5 50 16.8 12 500 225000 10 2.50 1969 10.3 15.0 60

Compare Lines 3 and 4: Fission can become the bottleneck!

Bottlenecks

• Ge rate. Present: 10 kHz/detector

• With digital electronics and high throughput preamplifiers: 30 kHz/detector, eventual aim is 100 kHz/detector

• DAQ must handle these rates to preprocess and write to tape. Data rates up to 50MB/s– BGO suppression– Recoil coincidence

Conclusions

• Decay studies will be possible without large changes to existing detector technology and electronics. Target/Separator are crucial.

• In-beam studies will need highest rate capabilities – electronics, DAQ. Target must allow the beam, 10 nb level possible.

Marie-Helene Moscatello / M. Levitowicz (GANIL)Annamaria Porcellato (Legnaro)Uli Ratzinger (GSI)

Sigurd Hofmann (GSI)Rauno Julin (JYFL)Faisal Azaiez (IPN-Orsay)Giacomo DeAngelis (Legnaro)Rolf-Dietmar Herzberg (Liverpool)

Task: Produce a document to NUPECC

-Physics-Collaboration-Physics requirements (accelerator,target,instruments)

-Study the up-grade of existing or new accelerators to mach the physics requirements

ECOS: European COllaboration for Stable (ion beams)

--The Science with high intensity stable ion beams, Beam intensity limitations and technical developments for various types of research lines!

N=Z nuclei (in–beam spectroscopy and decay studies) : G. DeAngelisSHE search : S. HofmannSuper heavy nuclei (in-beam spectroscopy and decay studies) : R. D. HerzbergNeutron-deficient nuclei (in-beam spectroscopy and decay studies) : R. JulinExotic shapes and decay modes in nuclei : F. AzaiezNeutron rich nuclei using DIC reactions : F. Azaiez & G. DeAngelisNuclear astrophysics: S.V. Harissopulos

--Status and future developments of existing facilities

LEGNARO : A. PorcellatoGANIL : M. H. Moscatello/M. LewitoviczGSI : S. Hofmann&U. Ratzinger

JYVASKYLA : R. Julin KVI : S. Brandenburg

--Recommendations Draft (quasi-final):NuPECC web pages.