Presentation on theme: "NuPECC Long Range Pan 2010 Nuclear Astrophysics Section Presentation to community Town Meeting Madrid 1 June 2010 Brian Fulton University of York."— Presentation transcript:
NuPECC Long Range Pan 2010 Nuclear Astrophysics Section Presentation to community Town Meeting Madrid 1 June 2010 Brian Fulton University of York
What is Nuclear Astrophysics? How the WG went about their job Brief summary of the science case Recommendations and Timeline Questions for community Feedback from community
From the first few seconds of the Big Bang which created the seed material for our universe, through to the present energy generation in our Sun which keeps us alive, nuclear physics has shaped the evolution of the universe and our place in it. Along the way, nuclear reactions have controlled the evolution and death of stars forming the most compact objects in the Universe, determined the chemical evolution of galaxies and produced the elements from which we ourselves are built. Our understanding of this complex evolution has developed as a result of nuclear physicists working closely with cosmologists, astrophysicists and astronomers in a hugely productive collaborative effort to understand the development of the universe and our place in it. Our first paragraph
An exciting cooperation between sciences Astronomical Observation Astrophysics Modelling Nuclear Physics Nuclear theory – global input for models Nuclear experiment – tests of key reaction rates
The Big Bang created only Hydrogen and Helium. All the other elements are created in a continuing cosmic cycle which involves the birth, life and death of starts
The different elements are formed in different classes on nucleosynthesis which occur in different astrophysical sites Big Bang Nucleosynthesis (H, He and small amounts of Li,Be) Nucleosynthesis in stars (Nuclei up to Fe and about half of heavier elements) Explosive nucleosynthesis (the rest of the heavy elements) ( Novae, X-ray Bursters, Supernovae...)
And to understand the nuclear physics aspects of these processes requires a knowledge of nuclei right across the chart of nuclides, including (and indeed mostly) very exotic nuclei Experimental information where we can, theoretical model calculations where we cant
European Pedigree Louvain-la-Neuve – worlds first radioactive beam facility for nuclear astrophysics LUNA – Worlds first (and still only) underground accelerator facility for nuclear astrophysics Plus world leading and innovative groups involved in low energy reaction rate measurements, nuclear theory for astrophysics and astrophysical modelling. The Bochum heritage
13 LUNA (Laboratory for Underground Nuclear Astrophysics) Information at and H Costantini et al 2009 Rep. Prog. Phys http://luna.lngs.infn.it/ Collaboration of 8 Italian groups plus one German and one Hungarian LUNA 1 50 kV LUNA kV Worlds first underground accelerator dedicated to nuclear astrophysics
14 3 He( 3 He,2p) 4 He PRL 82 (1999) 5205 min = 0.02pb (2 events/month) d(p, ) 3 He NP A706 (2002) 203 Early results on LUNA 1 (50 kV) on pp-chains
15 Recent results on LUNA 2 (400 kV) on CNO-cycle 14 N(p, ) 15 O PLB 634 (2005) 455 min = 0.24pb
16 CRC (Centre de Recherches du Cyclotron - Louvain-la-Neuve) Worlds first radioactive beam accelerator dedicated to nuclear astrophysics Further information at Many pioneering experiments on explosive (Novae and X-Ray Burster) reactions
17 R Coszach et al. PLB 353 (1995) 184 Direct measurement of 18 F(p, ) 15 O confirms model rate C Angulo et al. NP 758 (2005) 775 Shows no problem with nuclear physics input to Li abundance in BB calculations D Groombridge PRC 66 (2002) Direct measurement of 18 Ne(,p) 21 Na Suggests breakout will not occur in Novae Is the 7 Be produced in the BB destroyed by the 7 Be(d,p) 8 Be reaction before it can decay to form 7 Li?
For many decades Claus Rolfs has led a programme of nuclear astrophysics measurements 18 International workshop on: The role of low energy fusion reactions in nuclear astrophysics: carbon burning Villa Orlandi, Anacapri, Naples,Italy May 14th - 16th, 2009 Challenge for Laboratory nuclear-Astrophysics in Underground and Surface 2009: CLAUS2009 Bochum Contribution
19 Current experimental facilities JyvaskylaSB for mass measurements SPIRALRB for explosive nucleosynthesis Orsaynew electrofission source for radioactive beam GSIRB for mass measurements, explosive nucleosynthesis, r-process ISOLDERB for explosive nucleosynthesis and n-TOF for (n, ) LUNASB for stellar nucleosynthesis Karlsruhen-capture for s-process (kT=30keV n spectrum) ViennaAMS for grain analysis CataniaSB for stellar/ explosive nucleosynthesis (new RBF, EXCYT) Athens, Bucharest, Debrecen, Munich also have small SB programmes RB = Radioactive BeamSB = Stable Beam For details see entries in
20 Astrophysics modelling and nuclear theory activity Big Bang Nucleosynthesis (Orsay, Paris) Non thermal reactions for LiBeB, CR interactions, solar flares (Orsay) Main sequence stars (Geneva, Perugia) Evolved stars, AGB, WR (Barcelona, Geneva, Perugia, Torino) Novae (Barcelona) X-ray bursts and rp-process (Barcelona, Basel) SNIa (MPI-Garching, Barcelona) SNII, Ib/c (MPI-Garching, Rome) r-, s- and p-process (Brussels, Mainz, Perugia, Torino) Gamma ray astronomy (MPE-Garching) Shell model (Langanke, Martinez-Pinedo, Poves, Novacki,…) HF (Goriely, Raucher, Thieleman, …) Microscopic models (Baye, Descouvemont, Feldmeier,…) Indirect methods (Spitalieri, Typel, …) R-matrix (Angulo, Descouvemont, …) For contact details see CARINA website
2. Background – how the WG went about things The membership of the group approved by NuPECC was: Brian Fulton (York) – Convener Jordi Jose (Barcelona) Thomas Rauscher (Basel) Nicholas Chamel (Bruxelles) Fairouz Hammache (Orsay) Phil Woods (Edinburgh) Zsolt Fulop (Debrecen) Francois de Oliveira (GANIL) Stefano Romano (Catania) Paolo Prati (Genova) Kerstin Sonnabend (Darmstadt) Christof Vockenhuber (Zurich) Michael Heil (GSI) Paul-Henri Heenen and Sotirios Harissopulos as NuPECC members.
In preparation for the WG's first meeting at Frankfurt (12-13 October) each member of the WG prepared a two page report on their particular area of expertise. These were considered at the first meeting, and gave an initial view of the scope of the field and enabled us to identify areas where we were missing expertise As a result of this we requested to NuPECC that Gabriel Martinez Pinedo (GSI) join the WG and this was accepted.
The convener produced a first draft of the chapter based on the various text submissions, which was circulated to members of the WG for comment. During this stage members of the WG have sought comment from other colleagues on sections of the draft where we felt additional expert input was required. Based on feedback from WG members, the convener produced a second draft which was circulated for a check by WG members before being forwarded to the NuPECC Writing Group on 27 January for their comments The WG met for a second time at Orsay (21 December) when the detailed structure and content of the chapter was agreed and members of the WG tasked with preparing text for these. We also had an initial discussion on what the recommendations were likely to be.
In addition we have checked the material in other sections (WG3 on structure and reactions, WG5 on neutrinos, WG6 AMS and WG1/2 on EoS). What we find is consistent and the degree of overlap is relatively limited and at a suitable level. A phone conference was held with WG3/5 Conveners. The revised draft was presented to NuPECC at the Catania Meeting (12-13/3). Relatively little change was requested other than a shortening of the recommendations. The Convenor took advantage of a Workshop at Dresden (28-29/6) to present the report and initial recommendations to a good cross section of the NA community. Useful feedback was received which resulted in some changes to the recommendations on the underground facility section We received feedback from the Writing Group which we have responded to in a revised draft.
3. Brief outline of the science case Key questions 1.How and where are the elements made? 2.Can we understand, and recreate on Earth, the critical reactions that drive the energy generation and the associated synthesis of new elements in stars? 3.How does the fate of a start depend on the nuclear reactions that control its evolution? 4.What are the properties of dense matter in a compact object such as a neutron star or a hypothetical quark star?
Areas of research activity Three classes of nucleosynthesis Big Bang nucleosynthesis Stellar nucleosynthesis Explosive nucleosynthesis Physics of compact stars Principle need is reaction rates Light ion beams Stable/intense beams Radioactive beams Principle need is theory Weak interaction rates, cross sections, EoS, symmetry energy, hyperon matter Status Closing Mature Early Beginning
Overarching theme – very diverse field Accelerators:small university based (through underground) to international facilities Beams:gamma, neutron, particle, radioactive, (neutrino) Techniques:multi-detector arrays for beta, gamma, neutron, particle, neutrino spectrometers, traps, low backgrounds, AMS Theory:masses, lifetimes, decay rates, reaction models, optical potentials shell model, finite temperature effects, plasma modifications, screening effects, equation of state, neutrino rates etc.
A glimpse at (a few) examples of the science uncertainties We can model the initial (H) stage of burning in a star, but struggle with the second stage (He burning) and have no real understanding of the later stages. We havent been able to measure the (simple) 12 C(a, ) 16 O reaction accurately enough – this determines whether, among other things, a star will explode at the end of its life. We havent been able to measure the key breakout reactions that trigger explosive burning and so have no way of checking what the conditions (temperature, pressure etc) are when Novae and X-ray Bursters ignite. There is too little Li in the early universe – nucleosynthesis in the standard Big Bang model predicts much more. Most of our models of Novae, XRBs or SN are 1D, so convection, rotation and other vital aspects arent dealt with correctly.
Detailed explanations of the experimental measurements and theoretical developments which are needed to tackle these problems are contained in the main part of the report. The new experimental facilities which will be required for these studies are also described and many more problems We have no quantitative idea of the conditions inside a neutron star Supernovae dont explode – or at least so our models tell us We dont understand where the r-process(es) occur
4. Recommendations and Timeline We need to discuss these with you to ensure they are reasonable. We then need to go through the Recommendations that NuPECC has selected from these to make sure you are happy with that choice There is no significance to the order – it simply reflects the order in which the science areas were covered.
Nuclear astrophysics, perhaps uniquely, requires access to an extremely wide range of stable and radioactive beams and often involves very long periods of beam time. It is vital to maintain and enhance the existing network of complementary facilities that have been developed through past coordinated efforts in Europe, from the small university based to the large national laboratory based, to satisfy the increasing demand for these beams and to provide the essential time for instrument development and student training. This is the priority for the period through to 2015 and beyond. Along with the nuclear structure community (WG3) the nuclear astrophysics community is eagerly awaiting the completion of the next generation of radioactive beam facilities (FAIR, SPIRAL 2, HIE-ISOLDE and SPES) which will provide a rich variety of complementary beams needed to tackle more complex issues. This work will become important during the period These facilities are the precursor to EURISOL, which will be developed in the following decade.
During the period it will be essential to select and construct the next generation of underground accelerator facility. Europe was a pioneer in this field, but risks a loss of leadership to new initiatives in the USA. Providing an underground multi-MV accelerator facility is a high priority. There are a number of proposals being developed in Europe and it is vital that construction of one or more facilities starts as soon as possible. The small reaction yields typical of the field mean that high beam currents and extremely sophisticated experimental approaches are required. Towards the end of the decade a high intensity facility as envisaged in the ECOS proposal will be required to enable the nuclear astrophysics community to pursue the more challenging reaction measurements that are at present our of experimental reach.
Efforts must be made to strengthen the coordination between the nuclear physicists, astrophysical modellers and astronomers engaged in the field. The recently approved EuroGENESIS EUROCORES programme and the ATHENA network under the ENSAR IA in FP7 must provide leadership in this area. Nuclear theory and astrophysical modelling rely heavily on computing capabilities, both shared memory supercomputing and large cluster distributed memory nodes. The provision of such facilities is essential to progress as is the personnel to develop the theory and codes. Dedicated interdisciplinary positions need to be created at the interface between nuclear physics and astrophysics to ensure that this development can occur.
Exploitation and upgrade of present facilities Equipment designs for next generation RBFs Selection and construction of underground facility option Exploitation of next generation RBFs Exploitation of new underground facility Design/planning for NA programme on EURISOL Planning for high intensity stable beam facility 2020 onwards Construction of EURISOL Construction of high intensity stable beam facility Timeline
What has been selected for the Executive Summary? Using radioactive heavy ion beams for nuclear structure studies far off stability, applying In-flight fragmentation at FAIR and Isotope Separator and On-Line (ISOL) techniques at GANIL, CERN and INFN LN Legnaro Improving the capabilities of high intensity stable heavy ion beam facilities in Europe (the ECOS project) and planning for a new underground accelerator for nuclear structure and astrophysics studies Improving the support of smaller-scale facilities in Europe that e.g. vitally support physics projects at the largescale facilities and are of paramount importance for training and education in Nuclear Physics Advanced theory methods play a central role in answering the key questions addressed by experimental programmes. Dedicated and sustained efforts are needed to progress towards a quantitative description of atomic nuclei and hadrons. This will not be possible without a large coherent international theory effort. New challenges, often involving long-term programmatic research, require collaboration of nuclear theorists with experimentalists but also with computer scientists and applied mathematicians in the framework of project-oriented theory initiatives.
5. Questions for the community Is there too much emphasis on neutron stars and the advanced nuclear physics related to supernovae? As we are looking ahead to the science over the next decade, this will surely feature highly. But is the balance between near-term, mid-term and long-term right? There is not much mention of the ECOS project. There is a strong case that much work can be done with a high intensity stable beam facility. Is there a stronger case for this than we have judged? We would welcome guidance on this. There is not much mention of laser induced nuclear physics. We are aware of the ongoing developments related to the ELI project, but this is at a very early stage and we do not know the direction this will take. Again, we would welcome advice on this. Are you happy that what NuPECC have put in their Executive Summary related to this section is a fair reflection of the WG report? Has the competition between the potential underground facilities been covered in the right way?
Historically we have tried to coordinate nuclear astrophysics in Europe, the most recent being the CARINA network in EURONS and about to be replaced by ATHENA (Advanced THeory and Experiments for Nuclear Astrophysics) as a new network in ENSAR Has the community been successful? We now have EuroGENESIS starting, which brings together nuclear physicists, modellers and astronomers. Does this have the potential to act as a focus for European effort? Will that group be willing to provide leadership and a coordinating role? Will groups not in EuroGENESIS be willing to have this happen? How will the ATHENA network link in with this?
6. Feedback from the community Over to you
Along with the nuclear structure community, the nuclear astrophysics community is eagerly awaiting the completion of the next generation of radioactive beam facilities (FAIR, SPIRAL 2, HIE-ISOLDE and SPES) which will provide a rich variety of complementary beams needed to tackle issues that are more complex. These facilities are the precursor to EURISOL, which will be developed in the following decade. An immediate, pressing issue is to select and construct the next generation of underground accelerator facilities. Europe was a pioneer in this field, but risks a loss of leadership to new initiatives in the USA. Providing an underground multi-MV accelerator facility is a high priority. There are a number of proposals being developed in Europe and it is vital that construction of one or more facilities starts as soon as possible.
A particular future experimental challenge will be the measurement of neutron capture cross sections required for the analysis of branching along the s-process path. High- resolution data have been obtained for Gamow-Teller (GT) transitions, i.e. transitions involving the transformation between neutrons and protons with conserved parity, at KVI (Netherlands). These are crucial for constraining the theoretical calculations of electron capture rates on nuclei around iron and to validate theoretical calculations of weak interactions relevant for understanding supernovae explosions. Experimentally, it will be necessary to extend charge exchange experiments to unstable nuclei using radioactive ion-beams and inverse kinematics. Some of the mechanisms underlying the instabilities that appear during the collapse of supernovae cores will become accessible to experimental study at the NIF and PHELIX facilities at (in the USA and at GSI/FAIR, Germany).
A full understanding of supernovae explosions will require hydrodynamics simulations with accurate neutrino transport and high precision nuclear physics input. A better, microscopic and self-consistent Equations of State (EoS) constrained by the experimental data must be developed and implemented in future simulations. To exploit the potential of future neutrino detection fully, it is essential to have reliable estimates of neutrino-nucleus cross sections. The construction of a dedicated detector for the measurement of neutrino-nucleus cross sections, for example at the future European Spallation Source (ESS), would be a very valuable tool.
The development of new radioactive ion beam facilities like FAIR at GSI (Germany) and SPIRAL2 at GANIL (France), will open up for experimental studies of very exotic nuclei with direct impact on the modelling of compact stars. The analysis of multifragmentation in heavyion collisions will elucidate the structure at the crust-core boundary. The new experimental facilities, such as PANDA at FAIR, will allow for the efficient production of hypernuclei, offering new perspectives for studying hyperonic matter and the largely unknown hyperon-hyperon interaction. The properties of matter at very high densities are presently very uncertain. Future experiments like CBM at FAIR will provide decisive constraints and also help us understand the confinement phase transition between quark matter and hadronic matter.
Advances in nuclear theory for astrophysics will be strongly coupled to the development of improved nuclear structure theory. A special phenomenon relevant in astrophysical environments is the influence of free electrons in the plasma on reactions and decays. Accurate treatments for intermediate or dynamic screening and the dependence on the plasma composition have still to be developed. Furthermore, all stellar models studying nucleosynthesis are currently 1-dimensional. Future improved models using a multi-dimensional approach will require vastly more accurate input from nuclear reaction data and high performance computing resources.