Session CA: Accelerator Developments for Fundamental and Applied Nuclear Science

Applications of Nuclear Physics Accelerators for Photon Science

Synchrotron radiation has been extensively developed as a source of high brightness light for materials science, chemistry and biology. Gains in brightness of 12 orders of magnitude have been achieved over conventional x-ray tubes. Now a new evolution is being enabled using superconducting linear accelerators to produce coherent light with a brightness another 8 orders of magnitude higher still. We will review the prospects of this development for photon science.   

Recent Progress in RHIC Accelerator Science and Applications

In the recent years, as the only operational collider in the US, the Relativistic Heavy Ion Collider (RHIC) has established several successful upgrade projects, which improved the luminosity as well as the polarization. These projects include 3D stochastic cooling, state of the art polarized proton source, new electron beam ion source, etc. In the meantime, ongoing research for ``cooler'' and brighter beam is planned to launch gradually in the next few years, e.g. 56 MHz SRF storage cavity, electron lens, proof-of-principle coherent electron cooling, etc.. In this paper, we will introduce the recent progress of RHIC accelerator science and applications, with highlights for some of the projects.   

DIANA: nuclear astrophysics with a deep underground accelerator facility

Current stellar model simulations are at a level of precision such that nuclear reaction rates represent a major source of uncertainty for theoretical predictions and for the analysis of observational signatures [1]. To address several open questions in cosmology, astrophysics, and non-Standard-Model neutrino physics, new high precision measurements of direct-capture nuclear fusion cross sections are essential [1]. Experimental studies of nuclear reaction of astrophysical interest are hampered by the exponential drop of the cross-section [2]. The extremely low value of $\sigma(E)$ within the Gamow peak prevents measurement in a laboratory at the earth surface. The signal to noise ratio would be too small, even with the highest beam intensities presently available from industrial accelerators, because of the cosmic ray interactions with the detectors and surrounding materials. An excellent solution is to install an accelerator facility deep underground where the cosmic rays background into detectors is reduced by several order of magnitude [3], allowing the measurements to be pushed to far lower energies than presently possible. This has been clearly demonstrated at the Laboratory for Underground Nuclear Astrophysics (LUNA) [4] by the successful studies of critical reactions in the pp-chains [5] and first reaction studies in the CNO cycles [6]. However many critical reactions still need high precision measurements [1], and next generation facilities, capable of very high beam currents over a wide energy range and state of the art target and detection technology, are highly desirable. The DIANA accelerator facility is being designed to achieve large laboratory reaction rates by delivering high ion beam currents (up to 100 mA [7]) to a high density (up to 10$^{18}$ atoms/cm$^2$), super-sonic jet-gas target as well as to a solid target. DIANA will consist of two accelerators, 50-400 kV and 0.4-3 MV, that will cover a wide range of ion beam intensities, with sufficient energy overlap to consistently connect the results to measurements above-ground. In the present work the status of the US DIANA project [7], for underground nuclear astrophysics will be presented.\\[4pt] [1] E. G. Adelberger et Al., Rev. Mod. Phys. {\bf 83}, 195 (2011).\\[0pt] [2] C. Rolfs, W. S. Rodney, Cauldrons in the Cosmos, University of Chicago Press (1988).\\[0pt] [3] D. M. Mei and A. Hime, Phys Rev. D {\bf 73}, 053004 (2006).\\[0pt] [4] H. Costantini et Al., Rep. Prog. Phys. {\bf 72}, 086301 (2009).\\[0pt] [5] M. Junker et Al., Phys. Rev. C {\bf 57}, 2700 (1998).\\[0pt] [6] A. Lemut et Al., Phys. Lett. B {\bf 634}, 483 (2006).\\[0pt] [7] A. Lemut et Al., Phys. Rev. ST Accel. Beams 14, 100101 (2011).