A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z  

Litvinenko, V.

Paper Title Page
WGA10 Beam Dynamics Limits for Low-Energy RHIC Operation 75
 
  • A.V. Fedotov, I. Ben-Zvi, X. Chang, A. Kayran, V. Litvinenko, E. Pozdeyev, T. Satogata
    BNL, Upton, Long Island, New York
 
 

A strong interest in running RHIC at low energies in a range of 2.5-25 GeV/nucleon total energy of a single beam has emerged recently. Providing collisions in this energy range, which in RHIC case is termed “low-energy” operation, will help to answer one of the key questions in the field of QCD about existence and location of critical point on the QCD phase diagram. To evaluate the challenges of RHIC operation at such low energies there have been several short test runs during RHIC operations in 2006, 2007 and 2008. The beam lifetime observed during the test runs was clearly limited by machine nonlinearities. This performance can be improved provided sufficient time is given for machine development at these low energies. After the lifetime caused by nonlinearities is improved the strongest limitation comes from transverse and longitudinal Intra-beam Scattering (IBS), and ultimately by the space-charge limit. A significant luminosity improvement can be provided with electron cooling applied directly in RHIC at low energies. This report summarizes various beam dynamics limiting effects and possible improvement with electron cooling.

 

slides icon

Slides

 
WGA12 Simulation of Coherent Electron Cooling for High-Intensity Hadron Colliders 81
 
  • D.L. Bruhwiler, G.I. Bell, A.V. Sobol
    Tech-X, Boulder, Colorado
  • I. Ben-Zvi, V. Litvinenko
    BNL, Upton, Long Island, New York
  • Y.S. Derbenev
    Jefferson Lab, Newport News, Virginia
 
 

Novel electron-hadron collider concepts are a long-term priority for the international nuclear physics community. Effective beam cooling for intense, relativistic hadron beams will be necessary to obtain the orders-of-magnitude higher luminosities being proposed. Coherent electron cooling (CEC) [1] combines the best features of electron cooling and stochastic cooling, via free-electron laser technology [2], to offer the possibility of cooling high-energy hadron beams much faster. Many technical difficulties must be resolved via full-scale 3D simulations, before the CEC concept can be validated experimentally. The parallel VORPAL framework [3] is the ideal code for simulating the modulator and kicker regions, where the electron and hadron beams will co-propagate as in a conventional electron cooling section. We present initial VORPAL simulations of the electron density wake driven by single ions in the modulator section. Also, we present a plan for simulating the full modulator-amplifier-kicker dynamics, by through use of a loosely-coupled code suite including VORPAL, an FEL code and a beam dynamics code.


[1] Y.S. Derbenev, Proc. COOL07, 149 (2007).
[2] V.N. Litvinenko & Y.S. Derbenev, Proc. FEL07, 268 (2007).
[3] G.I. Bell et. al., J. Comp. Phys. (2008), in press.

 
WGE01 ERHIC Conceptual Design 388
 
  • V. Ptitsyn, J. Beebe-Wang, I. Ben-Zvi, A.V. Fedotov, W. Fischer, Y. Hao, A. Kayran, V. Litvinenko, W.W. MacKay, C. Montag, E. Pozdeyev, T. Roser, D. Trbojevic, N. Tsoupas
    BNL, Upton, Long Island, New York
  • E. Tsentalovich
    MIT, Middleton, Massachusetts
 
 

The design status of the high luminosity electron-ion collider, eRHIC, is presented. The goal of eRHIC will be to provide collisions of electrons and possibly positrons) on ions and protons in the center-of-mass energy range from 25 to 140 GeV, at luminosities exceeding 1033 cm-2s-1. A considerable part of the physics program calls for a high polarization level of electrons, protons and He3 ions. The electron beam is accelerated in a recirculating energy recovery linac. Major R&D items for the electron beam include the development of a high intensity polarized source, studies of various aspects of energy recovery technology for high power beams and the development of compact magnets for recirculating passes. In a linac-ring scheme the beam-beam interaction has several very specific features which have to be thoroughly studied. In order to maximize the collider luminosity, several upgrades of the existing RHIC accelerator are required. Those upgrades may include the increase of total beam intensity as well as transverse and longitudinal cooling of ions and protons.

 

slides icon

Slides

 
WGA28 IBS Suppression Lattice in RHIC: Theory and Experimental Verification 148
 
  • A.V. Fedotov, M. Bai, D. Bruno, P. Cameron, R. Connolly, J. Cupolo, A.J. Della Penna, K.A. Drees, W. Fischer, G. Ganetis, L.T. Hoff, V. Litvinenko, W. Louie, Y. Luo, N. Malitsky, G.J. Marr, A. Marusic, C. Montag, V. Ptitsyn, T. Roser, T. Satogata, S. Tepikian, D. Trbojevic, N. Tsoupas
    BNL, Upton, Long Island, New York
 
 

Intra-beam scattering (IBS) is the limiting factor of the luminosity lifetime for RHIC operation with heavy ions. Over the last few years the process of IBS was carefully studied in RHIC with dedicated IBS measurements and their comparison with the theoretical models. Recently, in order to suppress transverse IBS growth, a new lattice was designed and implemented in RHIC, which lowered the average arc dispersion by 30%. This lattice became operational during RHIC Run-8. We review the IBS suppression mechanism, IBS measurements before and after the lattice change, and comparisons with predictions.

 

slides icon

Slides