Mengna Bai

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The Relativistic Heavy Ion Collider (RHIC) provides collisions of the fully stripped gold ions for four experiments. This report shows results from measurements of the betatron functions within the Interaction Regions (IR) as well as in the arcs in both ”blue” and ”yellow” rings. A single quadrupole excitation or the beam position monitors’ RMS. values at(More)
Two ac dipoles with vertical and horizontal magnetic field have been proposed at RHIC for applications in linear and non-linear beam dynamics and spin manipulations. A magnetic field amplitude of 380 Gm is required to produce a coherent oscillation of 5 times the rms beam size at the top energy. We take the ac dipole frequency to be 1.0% of the revolution(More)
The AC dipole has been proven to be a powerful tool To further improve the luminosity in polarized proton operation of the Relativistic Heavy Ion Collider, correction of the horizontal two-third resonance at store is desirable. The long-lasting coherent beam oscillations, produced by the AC dipole, are used to measure 3Q,'s resonance driving term hsoooo(More)
The reaction kinetics of the heavy-light-heavy abstraction reaction F + HCl → HF + Cl on the ground electronic state potential energy surface (PES) is investigated theoretically by a recently developed ring polymer molecular dynamics (RPMD) approach. First, a new PES is developed by the permutation invariant polynomial neural network (PIP-NN) approach based(More)
T. Satogata∗†, L. Ahrens, M. Bai, J.M. Brennan, D. Bruno, J. Butler, A. Drees, A. Fedotov, W. Fischer, M. Harvey, T. Hayes, W. Jappe, R.C. Lee, W.W. MacKay, N. Malitsky, G. Marr, R. Michnoff, B. Oerter, E. Pozdeyev, T. Roser, F. Severino, K. Smith, S. Tepikian, and N. Tsoupas Brookhaven National Laboratory E-mail:,,(More)
The large scale application of non-evaporable getter coating in RHIC has been effective in reducing the electron cloud. Since beams with higher intensity and smaller bunch spacing became possible in operation, the emittance growth is of concern. Study results are reported together with experiences of machine improvements: saturated NEG coatings,(More)
Charged-pion-interferometry measurements were made with respect to the second-and third-order event plane for Au + Au collisions at root S-NN = 200 GeV. A strong azimuthal-angle dependence of the extracted Gaussian-source radii was observed with respect to both the second-and third-order event planes. The results for the second-order dependence indicate(More)
To achieve the RHIC polarized proton enhanced luminosity goal of 150.10" ccn~-%sec-' on average in stores at 250 GeV, the luminosity needs to be increased by a factor of 3 compared to what was achieved in 2006. Since the number of bunches is already at its maximum of 1 1 1, limited by the injection kickers and the experiments' time resolution, the(More)
For the symmetric reaction OH + H2O → H2O + OH, ∼48 000 data points are sampled and calculated at the level of the explicitly correlated unrestricted coupled cluster method with single, double, and perturbative triple excitations with the augmented correlation-consistent polarized triple zeta basis set (CCSD(T)-F12a/AVTZ). The data set is then employed to(More)