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The Russian-American gallium experiment (SAGE) Cr neutrino source measurementhttp://sro.sussex.ac.uk Wark, David and et al, (1996) The Russian-American gallium experiment (SAGE) Cr neutrino source measurement. Physical Review Letters, 77. pp. 4708-4711.

An equilibrium population of approximately 500 hydrogenlike U '+ ions and ten fully stripped U'-' ions has been produced and trapped in an electron beam ion trap at 198-keV electron energy. The equilibrium ionization balance, determined from the intensities of radiative recombination x rays, gives values of 1.55~0.27 and 2.82~0.35 b for the electron impact ionization cross sections of hydrogenlike and heliumlike uranium, respectively. These values are somewhat larger than relativistic distorted wave calculations, and much smaller than previous values inferred from stripping of accelerator beams. PACS numbers: 34.80.Kw, 32.30.Rj The hydrogenlike isoelectronic sequence of oneelectron ions is the simplest atomic system and the only one in which multielectron interactions are completely absent. For this reason the hydrogenlike ions, and atomic hydrogen itself, have been used for many years to obtain fundamental atomic structure information. Experiments include measurements of Lamb shifts, hyperfine splittings, and collision cross sections. The contributions of relativity and QED to atomic energy levels both scale as Z4, and are therefore most apparent in ions of the highest Z. Hence considerable attention has been given to the measurement of transition energies in hydrogenlike and other few-electron high-Z ions, especially the ions of uranium [1 -5]. The electron impact ionization cross sections for the tightly bound 1s electrons of high-Z elements are also of interest as a test of relativistic interactions in a simple atomic system. In spite of this interest, even the approximate size of the high-Z ionization cross sections for 1s electrons has been uncertain in view of an accelerator stripping measurement that obtained values 3 to 5 times larger than any theory for hydrogenlike and heliumlike uranium [6].Production of hydrogenlike or bare uranium ions is extremely difficult, requiring many ionizing collisions with small cross sections, at least one of which must have a center-of-mass energy above the 130-keV ionization potential of the uranium 1s electrons. These ions have previously been produced only in relativistic (-400 Me V/amu) accelerator beams stripped in foil targets, so x-ray measurements have had to deal with substantial Doppler shift corrections [1 -3]. Recently, high velocity U9'+ and U + ions have been stored in a ring [4], and deceleration to lower velocities has been proposed. Production of hydrogenlike and bare uranium ions at rest has been a long sought goal. %e report the first production of stationary hydrogenlike and bare uranium ions, along with a measurement of the electron impact ionization cross sections for producing them. The experiments were done with a high energy electron beam ion trap (EBIT) [7] which is an upgrade of an apparatus used previously to obtain the first measurements of electron impact excitation cross sections for very highly charged ions [8]. Approximately 5 x 104 highly charged uranium ions were trapped in the space charge potential of a compressed 198-keV electron b...

In early 2010, the Long-Baseline Neutrino Experiment (LBNE) science collaboration initiated a study to investigate the physics potential of the experiment with a broad set of different beam, near-and far-detector configurations. Nine initial topics were identified as scientific areas that motivate construction of a long-baseline neutrino experiment with a very large far detector. We summarize the scientific justification for each topic and the estimated performance for a set of far detector reference configurations. We report also on a study of optimized beam parameters and the physics capability of proposed Near Detector configurations. This document was presented to the collaboration in fall 2010 and updated with minor modifications in early 2011.