280 likes | 468 Views
Science of Rare Isotope Accelerator (RIA) and the Project Status Witold Nazarewicz (UT/ORNL). Introduction RIA Science RIA Facility RIA Project Status Summary. The Nobel Prize in Physics 2004 Gross, Politzer, Wilczek. heavy nuclei. few body. quarks gluons. vacuum. quark-gluon
E N D
Science of Rare Isotope Accelerator (RIA) and the Project Status Witold Nazarewicz (UT/ORNL) • Introduction • RIA Science • RIA Facility • RIA Project Status • Summary
The Nobel Prize in Physics 2004 Gross, Politzer, Wilczek heavy nuclei few body quarks gluons vacuum quark-gluon soup QCD nucleon QCD few body systems free NN force many body systems effective NN force The Nuclear Many-Body Problem radioactive beams electron scattering relativistic heavy ions
superheavy nuclei proton drip line neutron drip line Nuclear Landscape 126 stable nuclei 82 r-process known nuclei terra incognita 50 protons 82 rp-process neutron stars 28 20 50 8 28 neutrons 2 20 8 2
QCD • Origin of NN interaction • Many-nucleon forces • Effective fields subfemto… nano… Complex Systems Giga… Cosmos femto… Physics of Nuclei Quantum many-body physics Nuclear Astrophysics • In-medium interactions • Symmetry breaking • Collective dynamics • Phases and phase transitions • Chaos and order • Dynamical symmetries • Structural evolution • Origin of the elements • Energy generation in stars • Stellar evolution • Cataclysmic stellar events • Neutron-rich nucleonic matter • Electroweak processes • Nuclear matter equation of state • How does complexity emerge from simple constituents? • How can complex systems display astonishing simplicities? How do nuclei shape the physical universe?
Ab Initio Density Functional Theory asymptotic freedom… The ultimate goal of the physics of nuclei is to develop a unified, predictive theory of nucleonic matter We need access to neutron- or proton-rich nuclei • What is the mechanism of nuclear binding? • How do fission and fusion work? • What are the phases and symmetries of nucleonic matter?
Change of Shell Structure in Neutron Rich Nuclei Near the drip lines nuclear structure may be dramatically different. First experimental indications demonstrate significant changes No shell closure for N=8 and 20 for drip-line nuclei; new shells at 14, 16, 32
lifetimes > 1y Three frontiers, relating to the determination of the proton and neutron drip lines far beyond present knowledge, and to the synthesis of the heaviest elements What are the limits of atoms and nuclei? Do very long-lived superheavy nuclei exist? What are their physical and chemical properties?
Based on National Academy of Science Report [Committee for the Physicsof the Universe (CPU)] Question 3How were the elements from iron to uranium made ?
RIA intensities (nuc/s) Mass known > 1012 102 1010 10-2 Half-life known nothing known 10-6 106 Nuclear Input (experiment and theory) Masses and drip lines Nuclear reaction rates Weak decay rates Electron capture rates Neutrino interactions Equation of State Fission processes Supernova E0102-72.3 n-Star KS 1731-260 How does the physics of nuclei impact the physical universe? • What is the origin of elements heavier than iron? • How do stars burn and explode? • What is the nucleonic structure of neutron stars? X-ray burst p process s-process 4U1728-34 331 330 Frequency (Hz) r process 329 328 327 10 15 20 Time (s) rp process Nova Crust processes T Pyxidis stellar burning protons neutrons
r (apid neutron capture) process The origin of about half of elements > Fe(including Gold, Platinum, Silver, Uranium) Supernovae ? Neutron star mergers ? Open questions: • Where does the r process occur ? • New observations of single r-process events in metal poor stars • Can the r-process tell us about physics under extreme conditions ? Swesty, Calder, Wang
neutron capture timescale: ~ 0.2 ms Rapid neutroncapture b-decay Seed Equilibrium favors“waiting point” (g,n) photodisintegration Proton number Neutron number The r-process
Accreting neutron stars Neutron star(H and He burninto heavier elements) Companion star(H + He envelope) Accretion disk(H and He fallonto neutron star)
X-ray bursts (1735-444) 15 s ms burst oscillations Off-state Lum. 4U1728-34 KS 1731-260 331 330 Frequency (Hz) 329 NASA/Chandra/Wijnands et al. Superbursts 328 327 (4U 1735-44) 10 15 20 Time (s) StrohmayerBhattacharyya et al. 2004 6 h 18 18.5 time (days) Lines during bursts EXO0748-676 Cottam, Paerels, Mendez 2002 Deciphering observations of Hubble, CHANDRA …
Tests of the Standard Model Parity violation studies in francium 126 82 Weak interaction studies in N=Z nuclei EDM search in radium 50 protons • Specific nuclei offer new opportunities for precision tests of: • CP and P violation • Unitarity of the CKM matrix • … 82 28 20 50 8 28 neutrons 2 20 How will we turn experimental signals into precise information on physics beyond the standard model? 8 2
Applications: Science for the Betterment of Mankind “One of the frontiers of our science is to manipulate nuclei to create new elements and isotopes both for science and, eventually, for societal needs. Often, the applications rely on our ability to select specific nuclei with particular decay modes, half-lives, and energies. Perhaps most importantly, the field provides a superb venue for the important mission to educate and train the next generation of nuclear scientists, who will play key roles not only in basic research itself, but in myriad applied fields”. From : White Paper on the Intellectual Challenges of RIA, prepared for Dr. R. Orbach LENP generates over 40% of PhDs in nuclear science • Human Health • Environment, Geosciences, Oceanography,.. • Nuclear Energy • Food & Agriculture • Material Sciences • Chemistry and Biology • History, Art, Archeology • National Security: • Stewardship of the Nations Nuclear Weapons Stockpile • Homeland Security/Non-Proliferation • Diagnostics for High Energy Density Physics Facilities
Milestones in RIA DevelopmentNSAC has endorsed RIA six times • 1996: Advanced ISOL facility and MSU upgrade are given the highest priority for new construction within the field of nuclear physics in the United States in the DOE/NSF 1996 Long Range Plan . “We strongly recommend development of a plan for a next generation ISOL-type facility and its construction when RHIC construction is substantially complete”. • 1999: ISOL Task Force concludes “building a world-leading accelerator facility is a scientific imperative for the United States.” Task Force sets performance standards, recommends technical approach to facility and estimates cost. Task Force recommends commissioning Conceptual Design Report in the immediate future. • 2001: NSAC Subcommittee reviews RIA preliminary cost estimate: “reasonable” and “appropriate”. • April 2002 DOE/NSF Long Range Plan: “RIA is the highest priority for major new construction for nuclear physics in the United States.” • March 2003 NSAC Facilities Subcommittee: “absolutely central to nuclear physics” and “ready to initiate construction” • 2003 DOE RIA R&D Workshop -- 112 participants- DOE RIA R&D Panel – “credible reference designs exist” and “most of the potential risks … have now been removed” • January 04 NSAC Comparison of RIA and GSI: “very strong science case”, “upgrade of GSI will not duplicate the capability of RIA”.
Office of Science Facilities Plan (November 2003)
The Rare Isotope Accelerator • $1000M • $180M peak • Operating cost comparable to JLAB • Best facility in the world to study nuclei and pursue nuclear astrophysics (See Bond NSAC Subcommittee report) • Costs in line with other rare isotope facilities under construction or consideration • Must be unique and world leading in 2015, and serve the community for 20+ years.
Each of the Four Beam Energy Ranges is Required for Important Physics NUCLEAR STRUCTURE Framework of single- particle states and closed shells Interplay of deformation and single particle effects Physics at the proton drip line Heavy elements Indirect measurements of astrophysical processes APPLICATIONS ASTROPHYSICAL RATES Direct measurements of reactions in hot stars, rp-process and breakout of hot CNO cycle FUNDAMENTAL INTERACTIONS Fundamental symmetries. PV, EDM, Beta-decay studies of physics beyond the standard model Masses - r-process, rp-process, symmetries Nuclear moments by hyperfine interactions Beta decay studies of rare nuclei APPLICATIONS NUCLEAR STRUCTURE Limits of stability at drip lines Decay studies at the limits of stability Matrix elements connecting to ground state. E&M and breakup Halos and skins Fission barriers Indirect measurements of astrophysical processes Nuclear equation of state
Combination of Capabilities Unique to RIA • Optimized production technique for each isotope • Factors of 10-100 higher beam intensities for in-flight isotopes best facility to study the r-process path & structure at the n-drip line • Experiments with reaccelerated beams wide variety of nuclear structure and reaction techniques, direct measurement of reaction rates for astrophysics, production of new elements,.. • ISOL production with 10 X higher yields or more stopped (atomic parity violation, isotope harvesting & stockpile stewardship,..) & reaccelerated beams • Combination of in-flight separation & gas cell fast development path for stopped & reaccelerated beams of all elements • Facility optimized for and dedicated to experiments with rare isotopes
RIA User Community • Based on data collected for Long Range Plan, user community in the RIA areas of physics is comparable to those of RHIC and JLab. • Currently >800 members of RIA Users Group. • Expect 500-750 RIA users to participate in experiments each year. • OECD Megascience forum estimates ~2000 users of rare isotope facilities worldwide.
What happened since November’03? A Roller Coaster Ride (see http://www.orau.org/ria/for details) November 2003 DOE’s Office of Science 20-Year Science Facility Plan February 2004 CD-0 Mission Need approved February 2004 RIA Science endorsed by the interagency panel February 2004 NSAC RIA-GSI Report March 2004 RIA Theory Group Charter approved June 2004 DOE issues pre-solicitation form for RIA construction August 2004 Third RIA Summer School (ORNL, MSU, ANL, LBNL) August 2004 RIA Informational website established by DOE September 2004 RIAUO Charter Ratified (>800 scientists, 35 countries) October 2004 Draft Request for Proposals (RFP) posted by DOE February 2005 Administration FY2006 budget released (bad news for science) April 2005 Energy Secretary: “Very important program both for nuclear physics and national security” May 11, 2005 RIA Day in D.C. May 16, 2005 House markup recommendation: additional $6M to initiate the conceptual design process ??? RFP issued by DOE ??? CD-1, CD-2…
The study of nuclei remains a forefront area of science. Huge discovery potential Merit Relevant to many other fields and applications RIA is required advance the science in the next decade. Summary RIA: Connecting Nuclei with the Universe
Comparison of RIA to other RI Facilities • NSCL CCFis lower in yield by a factor of 100 for the lightest elements and more than 10,000 for heavier elements. No post acceleration capability. • ISAC/TRIUMF is limited to traditional ISOL production of ions. This means intense beams of a limited number of nuclides. • RIKEN RIF will have 400 MeV/u uranium, but with 100x less intensity and no post acceleration capability. • GSIwill have 1.5 GeV/u uranium but with 10-100 x less intensity and no post acceleration capability. It is also a multi-faceted facility with limited beam time. • Europe and Japan are discussing an advanced ISOL facility to complement GSI and RIKEN. ISOL limitations RIA has the performance to reach the scientific goals for which it was conceived