BNL, Upton, Long Island, New York, USA
Stony Brook University, Stony Brook, USA
The proof of coherent electron cooling (CeC) principle experiment is currently under commissioning and it is essential to have the tools to predict the influences of cooling electrons on a circulating ion bunch. Recently, we have developed a simulation code to track the evolution of an ion bunch under the influences of both CeC and Intra-beam scattering (IBS). In this paper, we will first show the results of benchmarking the code with numerical solutions of Fokker-Planck equation and then present the simulation results for the proof of CeC principle experiment.
BNL, Upton, Long Island, New York, USA
Stony Brook University, Stony Brook, USA
In the presence of coherent electron cooling (CeC), the evolution of the longitudinal profile of a circulating ion bunch can be described by the 1-D Fokker-Planck equation. We show that, in the absence of diffusion, the 1-D equation can be solved analytically for certain dependence of cooling force on the synchrotron amplitude. For more general cases, we solved the 1-D Fokker-Planck equation numerically and the numerical solutions have been used to benchmark our simulation code as well as providing fast estimations of the cooling effects.
BNL, Upton, Long Island, New York, USA
High-gradient CW photo-injectors operating at high ac-celerating gradients promise to revolutionize many sci-ences and applications. They can establish the basis for super-bright monochromatic X-ray and gamma-ray sources, high luminosity hadron colliders, nuclear- waste transmutation or a new generation of microchip produc-tion. In this paper we report on our operation of a super-conducting RF electron gun with a record-high accelerat-ing gradient at the CsK2Sb photocathode (i.e. ~ 20 MV/m) generating a record-high bunch charge (i.e., 2 nC). We briefly describe the system and then detail our experimental results.
BNL, Upton, Long Island, New York, USA
Fermilab, Batavia, Illinois, USA
Recent developments of the ERL-based design of future high luminosity electron-hadron collider eRHIC focused on balancing technological risks present in the design versus the design cost. As a result a lower risk design has been adopted at moderate cost increase. The modifications include a change of the main linac RF frequency, reduced number of SRF cavity types and modified electron spin transport using a spin rotator. A luminosity-staged approach is being explored with a Nominal design (L ~ 1033 cm-2 s-1) that employs reduced electron current and could possibly be based on classical electron cooling, and then with the Ultimate design (L > 1034 cm-2 s-1) that uses higher electron current and an innovative cooling technique (CeC). The paper describes the recent design modifications, and presents the full status of the eRHIC ERL-based design.
BNL, Upton, Long Island, New York, USA
Stony Brook University, Stony Brook, USA
Coherent electron Cooling (CeC)* is a proposed advanced beam cooling method that has the potential to reduce the ion beam emittance in significantly shorter time compared to existing cooling methods. The newly constructed linear electron accelerator for the CeC experiment can generate electron beams with the required beam parameters for effective cooling. In this paper, we show simulation studies for the CEC linac by using the PARMELA** and ELEGANT*** beam dynamics tracking codes.
* V.N.Litvinenko and Y.S.Derbenev, PRL 102, 114801 (2009)
** Lloyd M.Young, Parmela manual, Los Alamos National Laboratory
*** M. Borland, Elegant, Argonne National Laboratory (2000)
BNL, Upton, Long Island, New York, USA
To reduce the technical risk of the future electron-ion collider eRHIC currently under study at BNL, the ring-ring scheme has been revisited over the summer of 2015. The goal of this study was a design that covers the full center-of-mass energy range from 32 to 141 GeV with an initial luminosity around 1033 cm-2 sec-1, upgradeable to 1034 cm-2 sec-1 later on. In this presentation the baseline design will be presented, and future upgrades will be discussed.