Nuclear Structure Data Needs

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Nuclear Structure Data Needs

• Filip G. Kondev

kondev_at_anl.gov
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?

Collaborative meeting, Trento, May 28 June 1,
2007
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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?

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Where to find the data ENSDF?
Effort within NSDD network, under auspices of
IAEA. Database is managed by NNDC (BNL)
Contents Evaluated nuclear structure and decay
data for all known nuclei, organized in over 260
mass chains
ENSDF
Reactions (HI,xn?) (p,p) (n, ?), (n,xng) Coul.
Exc. (?,?), (a,xng) (d,p), etc.
Adopted (best values) Levels (E, J?, T1/2, ?, Q,
configurations) Gammas (Eg, BR, M,?, ICC)
Decays ?- ?? ? ?-n etc.
www.nndc.bnl.gov/ensdf
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Where to find the data - cont?
Atomic Masses (Audi, Wapstra)
Nuclear Science References (NSR)
www.nndc.bnl.gov/ensdf

• Pros
• effort that already exists - updated on regular
  basis
• (NSDD Network under the auspices of IAEA)
• ALL experimental NS data for ALL nuclei

ENSDF
RIPL
ENDF/JENDL/JEFF
NuBase

• 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

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Where to find the data - cont?
http//www.nucleide.org/DDEP_WG/DDEPdata.htm

• 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

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Where to find the data - cont?
http//amdc.in2p3.fr/web/nubase_en.html

• Pros
• based on ENSDF, but updated for recent data

• Cons
• updating time 5-8 years
• no spectral information
• continuity

Atomic Masses Evaluations?
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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)

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A N Z E E/T T1/2 E/T
Decay Mode E/T Delayed Particle Emission
E/T 0/1 0/1 b-
eb a 0/1 n p a
0/1 77 38 39 0.0 0 63 MS 12
0 0 100 0 0
0 10 1 2.2 0.5 0
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What Id 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

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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

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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 b-decay strength distributions from
decay schemes TAGS?