Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userModulator simulations for coherent electron cooling using a variable density electron beam
185
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
Increasing the luminosity of relativistic hadron beams is critical for the advancement of nuclear physics. Coherent electron cooling (CEC) promises to cool such beams significantly faster than alternative methods. We present simulations of 40 GeV/nucleon Au+79 ions through the first (modulator) section of a coherent electron cooler. In the modulator, the electron beam copropagates with the ion beam, which perturbs the electron beam density and velocity via anisotropic Debye shielding. In contrast to previous simulations, where the electron density was constant in time and space, here the electron beam has a finite transverse extent, and undergoes focusing by quadrupoles as it passes through the modulator. The peak density in the modulator increases by a factor of 3, as specified by the beam Twiss parameters. The inherently 3D particle and field dynamics is modeled with the parallel VSim framework using a $delta$f PIC algorithm. Physical parameters are taken from the CEC proof-of-principle experiment under development at Brookhaven National Lab.
rate research
Read More
Cooling of hadron beams is critically important in the next generation of hadron storage rings for delivery of unprecedented performance. One such application is the electron-ion collider presently under development in the US. The desire to develop electron coolers for operation at much higher energies than previously achieved necessitates the use of radio-frequency (RF) fields for acceleration as opposed to the conventional, electrostatic approach. While electron cooling is a mature technology at low energy utilizing a DC beam, RF acceleration requires the cooling beam to be bunched, thus extending the parameter space to an unexplored territory. It is important to experimentally demonstrate the feasibility of cooling with electron bunches and further investigate how the relative time structure of the two beams affects the cooling properties; thus, a set of four pulsed-beam cooling experiments was carried out by a collaboration of Jefferson Lab and Institute of Modern Physics (IMP). The experiments have successfully demonstrated cooling with a beam of electron bunches in both the longitudinal and transverse directions for the first time. We have measured the effect of the electron bunch length and longitudinal ion focusing strength on the temporal evolution of the longitudinal and transverse ion beam profile and demonstrate that if the synchronization can be accurately maintained, the dynamics are not adversely affected by the change in time structure.
We compare the method of Coherent Electron Cooling with Enhanced Optical Cooling. According to our estimations the Enhanced Optical Cooling method demonstrates some advantage for parameters of LHC.
We present analytic cooling and diffusion rates for a simplified model of coherent electron cooling (CEC), based on a proton energy kick at each turn. This model also allows to estimate analytically the rms value of electron beam density fluctuations in the kicker section. Having such analytic expressions should allow for better understanding of the CEC mechanism, and for a quicker analysis and optimization of main system parameters. Our analysis is applicable to any CEC amplification mechanism, as long as the wake (kick) function is available.
We present results of an experiment showing the first successful demonstration of a cascaded micro-bunching scheme. Two modulator-chicane pre-bunchers arranged in series and a high power mid-IR laser seed are used to modulate a 52 MeV electron beam into a train of sharp microbunches phase-locked to the external drive laser. This configuration allows to increase the fraction of electrons trapped in a strongly tapered inverse free electron laser (IFEL) undulator to 96%, with up to 78% of the particles accelerated to the final design energy yielding a significant improvement compared to the classical single buncher scheme. These results represent a critical advance in laser-based longitudinal phase space manipulations and find application both in high gradient advanced acceleration as well as in high peak and average power coherent radiation sources.
The Microbunched Electron Cooling (MBEC) proposed by D. Ratner is a promising cooling technique that can find applications in future hadron and electron-ion colliders. In this paper, we develop a new framework for the study of MBEC which is based on the analysis of the dynamics of microscopic 1D fluctuations in the electron and hadron beams during their interaction and propagation through the system. Within this framework, we derive an analytical formula for the cooling rate and benchmark it against 1D computer simulations with a agreement between the analytical and numerical results. We then calculate the expecting cooling time for a set of parameters of the proposed electron-ion collider eRHIC in a simple cooling system with one chicane in the electron channel. While the cooling rate in this system turns out to be insufficient to counteract the intra-beam scattering in the proton beam, we discuss how the electron signal can be amplified by two orders of magnitude through the use of plasma effects in the beam.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
