Nuclear Structure Data Needs Filip G. Kondev Collaborative meeting, Trento, May 28 –June 1, 2007 Outline  What kind of nuclear structure and decay data are needed – an incomplete list  Where to find the relevant data?  Suggestions on how to proceed in the future in order to update the corresponding nuclear astrophysics data libraries with the best available nuclear structure data?

2 What NS data are needed?  Priority 1 – masses & decay data masses, T1/2, decay modes & BR and delayed-particle emission probabilities  Priority 2 – level energies, quantum numbers, T1/2 of excited states, etc. depends on the site of nucleosynthesis s- and p-processes – near the valley of stability – a lot of data rp-process – at the proton-rich side r-process - at the neutron-rich side – much more data is expected in the future with the RIB facilities important for model (cross-section) calculations – level densities, partition functions, etc. important when we are dealing with isomers – cosmo- chronometers at the s-process path, but also many at the n-rich side including the atomic (electron) environment?

3 Contents: Evaluated nuclear structure and decay data for all known nuclei, organized in over 260 mass chains Where to find the data – ENSDF? Effort within NSDD network, under auspices of IAEA. Database is managed by NNDC (BNL) Adopted (best values) Levels: (E, J , T 1/2, , Q, configurations) Gammas: (E , BR, M, , ICC) Decays  -  +  +   - n etc. Reactions (HI,xn  ) (p,p’) (n,  ), (n,xn  ) Coul. Exc. ( ,  ’), ( ,xn  ) (d,p), etc. ENSDF

4 Atomic Masses (Audi, Wapstra) Nuclear Science References (NSR) Pros: effort that already exists - updated on regular basis (NSDD Network under the auspices of IAEA) ALL experimental NS data for ALL nuclei NuBase RIPL NuDat2 IE Where to find the data - cont? ENDF/JENDL/JEFF Cons: updating time – vary between 6 to 10 years in some cases not all data are relevant to the needs of the astrophysics community “strange” format

5 Where to find the data - cont? Pros: include comprehensive X-ray data updated on regular basis Cons: decay data only mostly for NE & metrology applications relevant to a handful of s-(p-) process nuclei

6 Where to find the data - cont? Pros: based on ENSDF, but updated for recent data Cons: updating time – 5-8 years no spectral information continuity Atomic Masses Evaluations ?

7 What would be useful to have?  although ENSDF is the best source for a variety of experimental NS and decay data, effort is needed to (i) extract the needed data for astrophysics applications in user defined formats & (ii) to update for recent discoveries (~30 new isotopes/yr)  results from model calculations should be also included – for many nuclei, especially on the neutron-rich side, experimental data do not exist  in an “ideal case scenario” - a merge between experimental & theoretical data is needed – development of a dedicated Astrophysics Nuclear Structure Data (ANSD) module – easily included into Reaclib (or any other library)

8 A N Z E E/T T1/2 E/T Decay Mode E/T Delayed Particle Emission E/T 0/1 0/1  %n %p  MS % % % ANSDM experimental data ansd_exp.dat theoretical data ansd_theo.dat merge ansd_merge.f (c; cpp) Bookkeeping ansd_exp(theo).comments ansd.data (ascii file) ansd.comments

9 What I’d like to propose?  ANL in collaboration with JINA and other interested groups can provide the Astrophysics Nuclear Structure Data (ANSD) module: updates will be provided regularly – once a year data will be peer-reviewed by expert(s) in the field  the ANSD module will be a merge between experiment & theory - it will include available experimental data for all known nuclei, together with predictions for those not yet known  the corresponding codes used to merge (manipulate) the experimental & theoretical data sets will be provided, together with subroutines that can read the corresponding data files

10 What would be the benefits?  Comprehensive & Complete: All related quantities will be provided, together with estimates of their uncertainties  Reliable: Data will be correctly represented  Up-to-Date: Consequences of new measurements will appear promptly – regular updates will be provided  Accessible: Data will be available in an user-defined format  You will have all that for FREE: sorry no charges

11 What about other data? Priority 2: level energies, quantum numbers, T1/2 of excited states, etc. – the needs for dedicated effort should be driven by the users and modelers – many of those can be find in ENSDF – if there is a need we can provide it Priority 1: usually a comparison between experimental and theoretical T1/2 is used to test the reliability of a particular model - what about the  decay strength distributions – from decay schemes & TAGS?