Bulletin of the American Physical Society
4th Joint Meeting of the APS Division of Nuclear Physics and the Physical Society of Japan
Volume 59, Number 10
Tuesday–Saturday, October 7–11, 2014; Waikoloa, Hawaii
Session 1WA: Science and Next Generation Experiments at FRIB and RIBF I |
Hide Abstracts |
Chair: Bradley Sherrill, FRIB Room: Kohala 1 |
Tuesday, October 7, 2014 9:00AM - 9:30AM |
1WA.00001: Scientific opportunities and plans for RIBF Invited Speaker: Hideki Ueno In the RIKEN RIBF facility, a large variety of heavy-ion beams are delivered at the energies $E/A\le $135 MeV and 230$-$345 MeV to the low- and high-energy beam ports, respectively, under the scheme of the cascade acceleration utilizing the four ring cyclotrons, at most, and one of the three injectors. At the high-energy ports, high current radioactive-isotope (RI) beams are produced and isotope-separated with the superconducting in-flight RI separator BigRIPS. They can be then transported to three spectrometers, ZD, SAMURAI, and SHARAQ, having different functions. Furthermore, a new isochronous storage ring (Rare RI Ring) and a gas-catcher RF ion guide system for slow RI beams (SLOWRI) are under construction downstream BigRIPS. The first beam commissioning tests of them will be conducted soon after the construction. Making use of these experimental key devices, BigRIPS-based experiments have so far been performed for $\sim$ 270 days since 2007. Among them, for instance, a series of $\beta $-$\gamma $ spectroscopy, the EURICA (Euroball RIKEN Cluster Array) project, has been unfolded since 2011 and invariant mass spectroscopy of extremely far unstable nuclei utilizing SAMURAI has started since 2012. In spring 2014, in-beam $\gamma $-ray spectroscopy was conducted in combination with the active liquid hydrogen target system MINOS that enables vertex position reconstruction. At the low-energy beam ports, SCRIT for e-RI scattering studies and GARIS-II for SHE researches have been installed. Their R{\&}D studies for regular measurements are in progress. The previous RI separator RIPS is also available. In the talk, recent results and future plans of the RIBF facility will be presented. [Preview Abstract] |
Tuesday, October 7, 2014 9:30AM - 10:00AM |
1WA.00002: Scientific Opportunities and Plans for FRIB Invited Speaker: Georg Bollen FRIB, the US's ``Facility for Rare Isotope Beams'' under construction at Michigan State University will be a world-leading rare isotope beam facility. FRIB will be based on a 400 kW, 200 MeV/u heavy ion linac and provide a wide variety of high-quality beams of unstable isotopes at unprecedented intensities, opening exciting research perspectives with fast, stopped, and reaccelerated beams. This talk will summarize the scientific opportunities with FRIB in the areas of nuclear science, nuclear astrophysics, and the test of fundamental interaction and symmetries, as well using isotopes from FRIB for societal benefits. Design features of FRIB and the status of the ongoing construction will be presented. [Preview Abstract] |
Tuesday, October 7, 2014 10:00AM - 10:30AM |
1WA.00003: Science with Q3D mode of SAMURAI Invited Speaker: Kimiko Sekiguchi Study of three-nucleon forces (3NFs) is essentially important in clarifying nuclear phenomena. Few-nucleon scattering, e.g. deuteron-proton ($dp$) elastic scattering, $dp$ breakup reactions, at intermediate energies ($E \sim 100$-$400$ MeV/nucleon) is one attractive probe to investigate the dynamical aspects of 3NFs, such as momentum and/or spin dependences. Direct comparison between the data and the rigorous numerical calculations based on bare nuclear potentials provides information of 3NFs. So far large 3NF effects are theoretically predicted and experimentally confirmed in the cross section minimum for $dp$ scattering at $\sim$ 100 MeV/nucleon. With the aim of clarifying roles of the 3NFs in nuclei the experimental programs with polarized deuteron beams at intermediate energies are in progress at RIBF. At RIBF polarized deuteron beams are available up to 400 MeV/nucleon by using the three cyclotrons, AVF, RRC and SRC. Highly polarized deuteron beams, typical values of which are 80\% of the theoretical maximum values, have been obtained at 250 and 300 MeV/nucleon. In order to extract detailed properties of 3NFs high precision data are needed. The Q3D mode of the SAMURAI serves as a high-resolution spectrograph in which the triplet-Q-magnets STQ in conjunction with the SAMURAI dipole magnet are used as analyzer magnets. The momentum resolution of this mode is estimated to be $p/\delta p \sim 3000$. The angular range is covered from $0-5$ degrees in the laboratory systems. Charge collection of the deuteron beam is performed with the Faraday cup installed downstream of the SAMURAI dipole magnet. This system suits for the study of high momentum transfer region in $dp$ scattering where effects of short range 3NFs are expected to be obtained. As the first measurement with polarized deuteron beams with the SAMURAI Q3D mode $dp$ scattering at very backward angles $160^\circ$-$180^\circ$ in the center of mass system is planned. [Preview Abstract] |
Tuesday, October 7, 2014 10:30AM - 11:00AM |
1WA.00004: COFFEE BREAK |
Tuesday, October 7, 2014 11:00AM - 11:30AM |
1WA.00005: Particle Spectrometers for FRIB Invited Speaker: A.M. Amthor FRIB promises to dramatically expand the variety of nuclear systems available for direct experimental study by providing rates of many rare isotopes orders of magnitude higher than those currently available. A new generation of experimental systems, including new particle spectrometers will be critical to our ability to take full advantage of the scientific opportunities offered by FRIB. The High-Rigidity Spectrometer (HRS) will allow for experiments with the most neutron-rich and short-lived isotopes produced by in-flight fragmentation at FRIB. The bending capability of the HRS (8 Tm) matches to the rigidity for which rare isotopes are produced at the highest intensity in the FRIB fragment separator. The experimental program will be focused on nuclear structure and astrophysics, and allow for the use of other cutting-edge detection systems for gamma, neutron, and charged-particle detection. Stopped and reaccelerated beam studies will be an important compliment to in-flight techniques at FRIB, providing world-unique, high quality, intense rare isotope beams at low energies up to and beyond the Coulomb barrier---with the completion of ReA12---and serving many of the science goals of the broader facility, from nuclear structure and astrophysics to applications. Two specialized recoil spectrometers are being developed for studies with reaccelerated beams. SECAR, the Separator for Capture Reactions, will be built following ReA3, coupled to a windowless gas jet target, JENSA, and will focus on radiative capture reactions for astrophysics, particularly those needed to improve our understanding of novae and X-ray bursts. A recoil separator following ReA12 is proposed to address a variety of physics cases based on fusion-evaporation, Coulomb excitation, transfer, and deep-inelastic reactions by providing a large angular, momentum and charge state acceptance; a high mass resolving power; and the flexibility to couple to a variety of auxiliary detector systems. Two designs have been proposed to meet these needs, ISLA, the Isochronous Separator with Large Acceptance, and an electromagnetic M/Q separator SUPERB, the Separator for the Unique Products of Experiments with Radioactive Beams. [Preview Abstract] |
Tuesday, October 7, 2014 11:30AM - 12:00PM |
1WA.00006: RI-induced reaction studies by new energy-degrading beam line, OEDO Invited Speaker: Shin'ichiro Michimasa The RI beam factory (RIBF) has expanded variety of accessible nuclei, and provides very intense RI beams. However, the beams are energy range of above 100 MeV/u, and are not necessarily suitable to some kinds of nuclear reactions. Therefore, deceleration of intense RI beams from RIBF open potentially new scientific opportunities to access various states in exotic nuclei by using characteristics probes, such as transfer reactions at several ten MeV/u and fusion reactions at several MeV/u. For energy degrading of nuclear beams, the degrader is generally used. This method easily controls beam energy, while multiple scattering effect and energy straggling in the material broaden the beam spot size at the downstream foci. Therefore, a key issue for reaction measurements is achievement of ion transport to reduce the beam emittance at the secondary target. For this purpose, CNS has set up OEDO (Optimized Energy Degrading Optics for RI beam) project for production of high-quality low energy RI beams. The OEDO beam line scheme is planned to be achieved by re-arrangement of magnets of the high-resolution beam line, where the SHARAQ spectrometer is useful as a spectrograph for low-energy reaction spectroscopy. In this presentation, I will discuss scientific opportunities in the OEDO beam line and the SHARAQ spectrometer. [Preview Abstract] |
Tuesday, October 7, 2014 12:00PM - 12:30PM |
1WA.00007: Solenoid Spectrometers for Reaccelerated Beam Experiments Invited Speaker: Alan Wuosmaa The coming availability of reaccelerated rare-isotope beam promises many new advances in the study of nuclear structure. Already, measurements of transfer reactions with unstable beams have provided new information about nuclei far from stability. The necessity of performing these experiments in inverse kinematics, however, introduces technical challenges that accompany the potential gains that can be achieved. These include the resolution of excited states in the nuclei of interest, the suppression of backgrounds from beam impurities, and the identification of the reaction products. One approach that has been developed recently to cope with these challenges uses the uniform magnetic field of a superconducting solenoid to transport light charged particles from the target to an array of position-sensitive silicon detectors, both of which are positioned on the magnetic axis of the solenoid. An implementation of this concept, called HELIOS (the HELIcal Orbit Spectrometer) has been in operation at the ATLAS facility at Argonne National Laboratory since 2008, and has been used to study a variety of nucleon transfer reactions with stable and unstable beams. The technical concept and examples of recent experimental results will be discussed, and opportunities for studies at future reaccelerated beam facilities will be presented. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700