Motivation Theoretical predictions Experimental requirements and setup

T. Adachi , P. von Brentano , D. Frekers , D. De Frenne , H. Fujita , Y. Fujita , A. Heger ,E. Jacobs , Y. Kalmykov , K. Langanke , E. Kolbe , A. Negret , P. von Neumann-Cosel ,

L. Popescu , S. Rakers , A. Richter , A. Shevchenko und Y. Shimbara

2 3 4 5 6 2 7

5 1 8 9 5 1

5 4 1 1 2

1 2 3 4

5 6 7 8 9TU Darmstadt — Osaka University — Universität zu Köln — Universität Münster

Universiteit Gent — University of Witwatersrand — Los Alamos — GSI — Universität Basel

Anatoliy ByelikovInstitut für Kernphysik, Technische Universität Darmstadt

Neutrino Nucleosynthesis of ExoticNuclides La and Ta138 180

Motivation

Theoretical predictions

Experimental requirements and setup

Results vs. RPA calculations

Summary and outlook

Outline

180Ta

138La

Exotic Nuclides

Nucleosynthesis of 138La

s-process r-process p-process

Production through Neutrino Process

Neutral current reactions: 139La(,‘n)138La 181Ta(,‘n)180Ta

Charged current reactions: 138Ba(e,e)138La 180Hf(e,e)180Ta

Complete stellar evolution in massive stars with the improved RPA calculations for -nucleus reactions

A. Heger et al., Phys. Lett. B 606 (2005) 258

138La: pure process nucleus

Different Production Processes of 138La

180Ta: 50% p process, 50% process (s process also not excluded)

Prediction

Low neutrino energies small q l = 0 GT strength RPA predicts main GT resonance well above neutron threshold

Experimental Requirements

(e,e) Gamow-Teller strength (p,n) or (3He,t)

Gamow-Teller part Narrow angle cut around 0°

Simple one step reaction mechanism Intermediate energies

Experimental Facility at RCNP

Grand Raiden

138La Spectrum

Target: 138BaCO4 embedded in polyvinylalcohol

B(GT) extraction

B(GT))(0JNK)σ(02

στστ

GT Strength Distribution in 138La

Comparison Experiment/RPA

B(GT–)exp 64% B(GT–)th at 7.47 MeV

180Ta Spectrum

Target: 180TaO2 embedded in polyvinylalcohol

GT Strength Distribution in 180Ta

Summary and Outlook

Analysis of 138La and 180Ta data completed

Good agreement found for 138La

Comparison with the theory for 180Ta underway

Integration into network calculations underway

PVA Spectrum

Nucleon-Nucleon Interaction: Ein Dependence at q = 0

Production of 180Ta

R2 Value

High Resolution WS Course

Conversion to B(GT)