Nuclear Physics A7 18 (2003) 339c-346~ wwwelsevier.com/locate/npe
data for astrophysics S. Smith”
a Physics Division,
In order to address important astrophysics problems such as the origin of the chemical elements, the inner workings of our Sun, and the evolution of stars, crucial nuclear datasets are needed. Recent evaluation and dissemination efforts have produced a number of such datasets, many of which are online and readily available to the research community. Current international efforts in this field are, unfortunately, insufficient to keep pace with the latest nuclear physics measurements and model calculations. A dedicated effort is required to update and expand existing datasets. I discuss several strategies and new initiatives that would ensure a more effective utilization of nuclear data in astrophysics. These include launching a new web site www.nucastrodata.org to aid in locating available nuclear data sets, and an interactive online plotting program with an easy-to-use graphical user interface to over 8000 reaction rates. An enhanced effort in this field could be maintained by formalizing the position of a Nuclear Astrophysics Data Coordinator.
Nuclear astrophysics research addresses some of the most fundamental questions in nature: What are the origins of the elements that make up our bodies and our world? How did the sun, the stars, and the galaxy form, and how do they evolve? There is an intimate connection between nuclear physics and studies of these fascinating astrophysical phenomena. A diverse set of nuclear data is required to model the composition changes and energy release in astrophysical environments ranging from the Big Bang to the inner workings of our own Sun to exploding stars. Measurements and theoretical descriptions of microscopic nuclear physics phenomena provide the foundation for the sophisticated models of macroscopic astrophysical systems. These models are today challenged by incredibly detailed observations from ground-based (e.g., Keck [I], SUBARU [Z]) and space-based (e.g., CHANDRA X-ray Observatory . Hubble Space Telescope ) devices that give us an u~~parallelecl view of the Cosmos. We t,ruly live in a golden age of astr0physica.l observations. However, our ability to decipher these observations requires, in many instances, more extensive and precise nuclear data than ever before. This symposium featured many examples of this cosmic sensitivity to nuclear physics , including: ‘2C~(cr,y)‘s0, which impacts the abundances produced in supernova explosions, the ratio of C to 0 after core He burning, and the subsequent evolution of massive stars; 7Be(p,y)sB, which helps determine the nature of the neutriuo oscillations; ‘*F(p,~)‘~0, w h’ICh ce 1 ,t ermines . the synthesis of ‘sF nuclei in novae: “O(c~,p)~~iI~. which impacts the hot CNO breakout in stellar rsplo0375-9474/03/$ - see front matter 0 2003 Published by Elsevier Science B.V doi:lO.l016/S0375-9474(03)00736-X
Physics A718 (2003) 339c-346~
L3(:(fw)~~o~ WI II‘c ,h influences the production of neutrons for t.he s-process in red to impacts heavy element abundance anomalies in metegiant stars; arid s’I
require an enormous the particular clat,a
range, nuclei involved) quantities are needed
varies greatly ? For reactions,
determine thermonuclear energy. Astrophysical cause they vary much
reaction S-factors more slowly
to be extrapolated to energies data needs involving react.ions neutrinos  have been recently
the astrophysical phenomena required information includes
rates and a processed with energy below which induced by written.
Nuclear structure data is invaluable stellar energy generation. and nuclear includes: masses, decay lifetimes and
of nuclear reaction and nuclear (e.g., reaction type, relevant studied cross
. What sections to
Q-values to determine releases of nuclear cross section ~ are also extremely useful hethan cross sections, enabling cross sections
they have been charged particles
to determine reaction pathways. branching ratios,
measured. [‘i]; by
rates of unmeasured Some of the relevant pa.i-ameters of resonances
details [S], and
reactions, information (energies,
spins, parities, widths) above particle capture thresholds, separation energies near the driplines, alpha-nucleus potentials? level densities, and optical model parameters. Some specific nuclear structure data needs are addressed elsewhere in these proceedings, and general data needs for astrophysics have been reviewed recently [lo].
Willy Fowler and information tailored
were the in astrophysics
to produce simulations
estensive [II]. ‘rhe
grown into an international effort, as the variety, simulations has increased over the last 35 years. of the importance of the nuclear astrophysics impressive array of resoiirces have been produced
sophist,ication, There is now au data work that and, iii many
13.4). Laboratory evaluations, and
nuclear measurements, data clissrn~ination
nuclear astrophysics area.s is describrtl
clat ascts. Some in the sllbsrctions
rluclear are all vital
of these resources to follo\v.
and detail international he initiated cases, put
nuclear for the
sets of nuclear physics work he initiated has
of astrophysics recognition , and online (Section
clat,a compilations and production of important progress
urlstable of nuclei
isotopes that. that previollsly
at radioactive cesses [l/I]. sureiiit~iits
is our the
of the direct
drive stellar explosions [I31 , a\ nrll coultl o111y be est irllatecl by tlleory
:I no tl ler nr’\v at lo\v
as mapping or systematics.
arc air-eatly changing 0111’ untlerstautling iii esperiilic,iltal nuclear ast,rophysics
of react,ioiis out,
of astrophysical iilvolvcs malting r~tliictions
the propert,ies i\Ieasurelnent,s
Moratories reaction energies
[ 151 or via coincitlcnce section has for the in t.he core of our
teclluiqlles first, Sun
been directly an untlergrouncl The current [I:J.l’i],
measured at the estrmlely accelerat,or facility [iii], status of nuclear measurements
Since needed cosmos. trapolate which to modeling predictions
astrophysics They not only
nuclear models essential unmeasured
a crucial information,
role in studies hut a.re used
measurement,s to new energy regimes as well as to provide a framework with understand laboratory results. Significant advances have been made in riucleal in recent years, with a IKW focus on global nlicroscopic models t,hat ~a.11 deliver with accuracies rivaling those of phenomenological ~notl~ls tuned for a spc-
cific mass range of and reactions
[IS]. There involving
have been a nlmk~er of impressive calculations of properties thousands of nuclei, including references [IS -201 and others It is crucial to benchmark these global calculations with
discussed in this symposium. experimental measurements wherever important in this regard, as they are nuclear lanclsca,pe.
t inle with
more such studies are pla.nnetl in the future. for astrophysics has been recently reviewed the lat,est work in the field.
Physics A718 (2003) 339c-346c
Compilations tory measurements
Radioactive the exploration
beam facilities of uncharted
are especialI! parts of tile
evaluations and theoretical
the first calculations
towards incorporating for astrophysics
Compilations involve collecting all available information on, for example, a particular reaction or nucleus; literature searches play an important role here. Evalliat,ions are one of the most labor-intensive of all nuclear data activities. New evaluations ml& he initiated t,o combine the lote.d and cwwnt results to get a truly btsl result for the quantities of interest. This tra~polations. new evaluat,ions
often involves combining disparate datasets and performing necessary cx(Recent successful nuclear data evaluation projects for ast,rophysics include: of S6 important chargccl-particle rextions front the NAC’IIF: collahora-
tion in Europe ; a new large collection of neutron-inclllcecl reaction rvalllations [%‘I; a new collection of 56 charge&particle reaction rate evaluations for st,ahk a.ntl protonrich unstable isot,opes in the mass 20 - 40 region [zY]; and evaluatioris of a rtllrnber of crucial
scrihctl bc~low. for astrophysics
It is not enough to perform culations antl then to compile ttisl~ribr~tttl t,o Ihc comlnuriity into
cllrrcnt up Ivith
Ilialll)oIver t,hc pace
tlrvolecl to of ~vorltlwitle
date-of-t.lle-art nuclear nieasurements and rvaluat,e this irlforlJlatior1. Nuclear in fornlats that astrophysics researchers this
eva.lilatiolls aud lllodcting
or ttieolrt~ical calMa Illust a.lso tx> can directly insert
Physics A718 (2003) 339c-346~
vated their generation. Dissemina,tion work provides another crucial link between nuclear physics activities and astrophysics modeling. The modern mechanism for rapid, user-friendly information distribution is electronic dissemination via the World Wide Web (WWW). S’g I ni fi cants strides have been made in nuclear astrophysics data dissemination in the pa.st six years: researchers can now search, browse, display, and down1oa.d data sets specialized for nuclear astrophysics studies (e.g., reaction rates), as well as those for general nuclear physics research, from the WWW. The first website dedicated to disseminating nuclear data relevant for astrophysics  was launched in 1996, and now there are sites at numerous institutes around the world ~ including ORNL , LANL [‘ST], ULB [2S], LLNL , Ba.sel , KFI< , IAS , and Cambridge . Many of these sites feature datasets developed at the host institute and links to other datasets of interest. 4. Brewing
In spite of the impressive collection of online resources cited above: there are a number of reasons why the current effort in nuclear astrophysics data is insufficient to meet the needs of the research community. First, the subcritical manpower in this area simply cannot keep up with the worldwide pace of nuclear measurements and modeling efforts. There are, for example, numerous published reaction rates based on experimental measurements made in the last decade that have never been compiled or evaluated. Second, many of the specialized astrophysical datasets (e.g., [21,22]) are not folded into the existing large reaction rate libraries, and are therefore not widely utilized in astrophysics simulations. This is a terrible waste of resources, and one that is growing worse as more up-to-date information from recent nuclear measurements is not accessible to astrophysicists. Third, many very valuable clatasets lack a user-friendly interface or a data format appropriate for astrophysics models, req$ring significant,effort by researchers to use the data. Fourth, there is little coordination and communidation between groups working in this area. Researchers often create their own sets of nuclear data culled from scattered data collections of their choosing, making it extremely difficult to compare results from different groups, or to update popular simulation codes. This confusion is exemplified by REACLIB , a widely-used collection of approximately SO00 thermonuclear reaction rates. REACLIB is becoming a standard rate library used by numerous research groups around the world to simulate a wide variety of astrophysical phenomena. The last full update and public release of REACLIB was, however, in 1991, and there are currently numerous versions of this library in use (e.g., [23,33-371). B ecause each of these versions is updated from the last public release in a different way, it is very difficult, and possibly misleading to compare results from simulations using these libraries. Another serious problem: there is no mechanism whereby nlistakes in REACXIB r&es call be communicatecl to REACLIB users. This dataset also lacks a friendly interfacr, and there are many important ra.te collections that have not yet been incorporated into this library. Significant progress was realized in other fields (e.g.> reactor physics in t,he U.S. in the 1970s) when standardized sets of data were widely available to resea,rchers (e.g.. the Fusion Evaluated Nuclear Data Library or FENDL [3S]), a 11owing the model codes to be decoupled from the input data. Some ast,rophysicists will always prefer to use propriet,ary
M.S. Smith/Nuclear data
Physics A718 (2003) 339c-346~
of freely available, regularly updated. communal datasets would lead to a st,andardization that would help advance the field and would encomage the development and improvement of the input datasets themselves in a synergist,ic way. For example, REACLIB has evolved from and
a tool developed for use its utility for astrophysics
Working Group some of which are needed for
manpower for this and evaluation
e exploiting communities
the significant overlap between . For example, members of
on nuclei to focus astrophysics
stages in stars . A partial mass less than
, and neutronlist of evaluation 40 needed to supin the Caughlan and are now out at the proton-
from 0 to Si that generate on evaluation projects that discussed in Section 3.1.
primarily t.akr the establishment
duties would be dissemination The dissemination duties of nuclear
important for There are many charged-particle
is so limited, it is important to coordinate plans in order to share expertise and
(CSEWG)  evaluate reactions are also critical for astrophysics. astrophysics research, including
field, coordination he greatly facilitated whose core participation.
beam facilit,ies; approximately 80 reactions w h’ ICI1 were not, upclated by NACRE  compilations of nuclear structure information
and (cu, n) reactions It is especially important in experimental nuclear
for quiescent and explosive burning for the synthesis of heavy elements reactions on radioactiv? isotopes with
and neutron-driplines; for the s-process. the frontier areas
Because the wide compilation
likely requir astrophysics
port new work at radioactive and Fowler 1985 collection of dat,e by 14 years; enhanced
evaluation effort is required if accurate, up-to-date nuclear in a timely fashion for astrophysical studies. While most have been produced by nuclear astrophysics researchers, an
effort will most data and nuclear
reactions reactions includes:
a tremendous community could be ensured by
efforts in measurements and nuclear modeling. This endorsed in reports from meetings of the International as well as by an Aclvisory Group for Long Term Nuclear International Atomic Energy Agency. Below. some of
Cross Section Evaluation a variety of applications, important datasets that induced induced projects
An expanded, dedicated datasets are to be produced evaluation efforts to date expanded nuclear
to keep pace with the international recommendation has been recently Nuclear Data Committee [39,40], Data Development [7,12], of the the
researchers for the
by a few research
t,he form of enhanced communication. of a Nuclear Astrophysics Data ant1 communication, as wrll would include: ma.intaining tlata.sets
as active reupdating
ing tla.tasets of tlatasets phies: error
for compatibility via the creation checking, plotting
woultl include: publicizing or currently in progress;
with ast.rophysical of indices, search tools, and other
list; publicizing relevant scientific important nuclear reactions and interests in the nuclear national data activities of kchnical expertise
data project.s that are a nuc1ea.r astrophysics
establishing for further
maintaining a priority list of helping t,o build on common
&da. and nuclear astrophysics communities; and promoting intersuch as cooperative research progra.ms, symposia, and exchange and computer codes. It is crucial that. the Coordinator be actively
and be sited the Coordinator
Also, of the
at a location is a mrmher
by being a data user community.
an active research group of the research community the
to ensure initiativc>s
been launched an extensive
5.3.2. Much is posted loading,
in the form progralnming.
of tables, plotting)
V’’ lewable add new
which usually to visualize.
ttlrough rates aild
astrophysics studies. This site helps users publicize then1 to the research community. and does not compete with any esisting support, this website will grow int,o a
astrophysics require i\‘hile
reaction rates [26,X]. no site has a user-friendly, the largest reaction rate databases. To address heen developed which provides au easy-k-use. library [N]. parameters,
with support from set of links t,o nuclear
the world (over 60 so far) important for nuclear navigate through these datasets, as well as to The site is independent of auy host, institution nuclear astrophysics d;tt,a sit,e. With community very
of information posted online [25-331, t,here has been little synergy nuclear astrophysics data websites, and there is no site which links dotasets relevant for astrophysics studies. To rectify this situation,
the wealth the existing available ~zuclenr-
a widespread are discussed
Despite between all
cocks; and improving the user interface capabilities, graphical interfaces, bibliograenhancements. The communication duties
astrophysics and maintain meetings; properties
involved in a.strophysics resea.rch, . This will help ensure that tha.t he will int,erface he able to fulfill the
Physics A718 (2003) 339c-346~
interactive this need. interactive,
a web browser, plol, them, arid
a number of steps some sites feature
plotting package a. new visualization I’Iat,form-indepentlellt.
reactions ilsc’rs creatr
through a point-an&click graphical user interface bad S uc h visua .. 1’iza t’ ion t 00 1.s \\If’ll mos ,t l’kI e 1y Ime c I e\c i I opcd for websites in conlillg J’ears.
by the user (downpre-made plot,s of
accesses  has graphi-
vs. temperature“ t,ables all on t Ike c.ha.rt, of the Iluclitlcs. IlIaIIy uuclear astrophysics tla.ta
Physics A718 (2003) 339c-346~
6. Summary Nuclear physics informat.ion is crucial for the u~~tlerstanclir~g of many phenomena ill astrophysics. There is a wealth of IIIICIF‘X astrophysics data already online. Dctlicatctl effort is nettled, however, to ensure that these da.tasets are upda.tetl to illcluclc the latest experimental and theoretical work, autl t,o ensure that the limited maupowc’r in the ficltl works in a coordinated fashion. It is int,ernationally recognized that the current effort, in this area must be enhanced. A number of strategies to improve the utilization of nuclear data for astrophysics studies llave been identified, and some new init,iatives - a web site www.nucastrodata.org and a. new interactive reaction rate plott,ing program. are already helping to reach these goals. Community support for these autl similar cff’orts is essential to ensure that Willy Fowler’s legacy in nuclear data for astrophysics will continue t,o flourish in support of frontier xsearch in nuclear astrophysics. 7. Acknowledgment ORNL is managed by UT-Battellc, LLC, for the U.S. Department of Energy uncle1 contract DE-AC05-OOOR22725. The author thanks R.A. Meyer and D.W. Bartlayan f’o~ useful comments. REFERENCES 1. 2. 3. -1. i ‘. 6. 7. S. 9. 10.
Il. 12. 13. 14.
http://ww2.keck.hawaii.e& http://www.subaru.naoj.org http://chandra.harvarcl.eclu http://hst.stsci.edu/ this proceedings: 7th Int. Symposilml on Nuclei in the Cosmos. Fllji-Yoshida., Japan. July 2002. C.E. Rolfs, W.S. R.oclncy, C’nuldrons in the Cosrr~os: Nuclear .-lstr0physic.s (I!niv. Chicago, Chicago) 19%. M.S. Smith, IAEA Report IND(‘(NDS)-42S, p. 71 (2001). F. Iiacppeler, IAEA Report INDC’(NDS)-42S, p. 61 (2001). G.C. McLaughlin, G.M. Fuller, .4strophys. J. 455, 202 (1995); 466. 1100 (1996). M.S. Smit,h, in Proc. Int. Conf. 011 Nuclear Data for Science and Technology ND2001. Tsnkuba, Japan, Oct. 7-12, 2001, cd. A. Hasegawa, Journal of iVuc/mr Scirracf rind Technology. in press (2002). W.,A. Fowler. G.R. Caughlan, B.A. Zimmernlan, Ann. Ret:. .tl s-f 1’011..4.sflophyY. 5. 5% (1967). Muir. 11.W.. and Herman, M.. IAE.-l Report INDC(NDS)-423, 7 (2001). M.S. Smith, K.E. Rchm, cln7l. flru. !Vucl Part. ,Sci. 51, 91 (2001). M.S. Smith et al.; in Pro<:. Int,. Synlp. Nuclear Science with Radioactive Beams at, ISOL Facilities (ISOL’OI), etls. (‘..I. Gross, D. Dean. S1.S. Slnith. htt~~://~vw~v.~~liy.orr~l.go~/~~rit~f/isolOl/p~~ocee~li~igs/~ns/sinitl~.~~~lf (2001). C!. Arpesella et al., Phys. Mt. B389. 4.5% (1996). ('. l~owhtl et al., Xd. Iu.strtrru. :Zf~th. A480, 610 (2002).
175 (199s). S. Goriely, P. Moller.
Physics A718 (2003) 339c-346~ iU. Wiescher,
IAEA Report J.R. Nix, K-L.
INDC(NDS)-42S, Iiratz, At.
et al., et al.,
M.S. Smith et Related Topics,
p. S3 (2001).
Data Nucl. Data, Tables 66, 131 (1997). At. Data Nucl. Data Tables 75, 1 (2000);
T. Rauscher, F.-K. Thielemann, http://cluasar.physik.unibas.ch/Ntommy/reaclib.html C. Angulo et al., Nucl. Phys. A656,
22. Z.Y. Bao
AWL Rev. Nucl. Part.
At. Data Nwl. Data Tables 76, 70 (2000). Astrophys. J. Suppl. 134, 1.51 (2001). al., in Proc. 10th ed. S Wencler,
25. 26. 27.
http://ie.lbl.gov/astro.html http://wlvw.phy.ornl.gov/astrophysics/data/data.html http://t2.lanl.gov/data/astro/astro.html
28. 29. 30.
htt,p://www-astro.ulb.ac.be/ http://www-phys.llnl.gov/Research/RRSN/ http://quasar.physik.unibas.ch/
Proc. 529, 243 (1999).
31. http://ik3frodo.fzk.de/bao_tab.html 32. http://www.sns.ias.edu/Njnb/SNclata/sndata.l~tml 133. http://www.ast.carn.ac.uk/Nmal/fitteclrates.ht~~~l
F.-K. Thielemann et al., Adu. Nuclear Astrophysics http://yuasar.physik.unibas.ch/-tommy/adndt.html#reaclib S. Starrfield et al., Astrophysical J. Suppl. 127, 465
H. Schatz W.R. His,
3s. 39. 40. 41.
http://iaeand.iaea.or.at/fendl/ A. Nichols, IAEA Report INDC/P(02)-1, (2002). M.S. Smith, R.A. Meyer, IAEA Report INDC/P(02)-22, M.S. Smith et al., U.S. Nuclear Data Program Astrophysics
unpublished (1995); http://www.plly.orlll.gov/astrophysics/data/task/taskforce-report.html ht.t~~://wmw.~~~~clc.bnl.gov/Nmclar~e/csewg/
et al., private
Caughlan, Pa.rker et
Phys. Rev. Lett. 86, 34i’l communication
htt~p://ie.lbl.gov/whitepaper.htn~l 4.5. E. Lingerfelt et al., Bull.
A.m. Phys. Sot.
Tables 40, 253 (198s).