BNL, Upton, Long Island, New York, USA
Stony Brook University, Stony Brook, USA
RHIC operations with heavy ion beams at energies below 10 GeV/nucleon are motivated by a search for the QCD Critical Point. An electron cooler is proposed as a means to increase RHIC luminosity for collider operations at these low energies. The electron cooling system should be able to deliver an electron beam of adequate quality over a wide range of electron beam energies (0.9-5 MeV). It also should provide optimum 3-D cooling for both hadron beams in the collider. A method based on bunched electron beam, which is also a natural approach for high-energy electron cooling, is being developed. In this paper, we describe the requirements for this system, its design aspects, as well as the associated challenges.
BNL, Upton, Long Island, New York, USA
A future electron ion collider "QCD test facility" is designed in the present Relativistic Heavy Ion Collider (RHIC) tunnel. Electron acceleration and de-acceleration is preformed with energy recovery linac with multiple passes. We report on a combination of a multi-pass linac with the Non-Scaling Fixed Field Alternating Gradient (NS-FFAG) arcs. A single NS-FFAG arc allow electrons to pass through the same structure with an energy range between 1.425 and 10 GeV. The NS-FFAG is placed in the existing RHIC tunnel. The 200 MeV injector bring the polarized electrons to the 1.225 GeV GeV superconducting linac. After one pass through the linac 1.425 GeV electrons enter NS-FFAG arc and after 7 passes reach the energy of 10 GeV. After collisions the beam is brought back by the NS-FFAG and decelerated to the initial energy and directed to the dump.
BNL, Upton, Long Island, New York, USA
A proposal for the new high luminosity L=1034 s-1 cm-2, polarized electron proton/3He and other un-polarized heavy ions eRHIC based on Electron Recovery Linacs (ERL), assumes a location in the existing tunnel of the operating Relativistic Heavy Ion Collider (RHIC). Requests of the experiments for the interaction region are very challenging: allow detection of neutrons, allow deep virtual scattering for protons-electron collisions, detection of partons with lower momentum, etc. We present an interaction region (IR) design with a vey high focusing where at the collision point IP of 5 cm, and a 10 mrad collision angle between electrons and ions using the crab cavities. We are introducing a combined function magnet for the first element in the high focusing triplet configuration to provide neutron and the lower energy parton detection, and allow at 4.5 cm distance passage of electrons through a no magnetic field region. The 200 T/m gradient quadrupoles provide very small beam size at the IP and allows a passage with a very small magnetic field for electrons.
BNL, Upton, Long Island, New York, USA
Niowave, Inc., Lansing, Michigan, USA
A 5-cell SRF cavity operating at 704 MHz will be used for Coherent Electron Cooling Proof of Principle (CeC PoP) system under development for the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The CeC PoP experiment will demonstrate the ability of relativistic electrons to cool a single bunch of heavy ions in RHIC. The cavity will accelerate 2 MeV electrons from a 112 MHz SRF gun up 22 MeV. Novel mechanical designs, including the super fluid heat exchanger, helium vessel, vacuum vessel, tuner mechanism, and FPC are presented. Structural and modal analysis, using ANSYS were performed to confirm the cavity chamber and He vessel structural stability and to calculate the tuning sensitivity of the cavity. This paper provides an overview of the design, the project status and schedule of the 704 MHz 5-cell SRF for CeC PoP experiment.
BNL, Upton, Long Island, New York, USA
A Quarter-Wave Resonator (QWR) type SRF gun operating at 112 MHz will be used for Coherent Electron Cooling Proof of Principle (CeC PoP) system under development for the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The CeC PoP experiment will demonstrate the ability of relativistic electrons to cool a single bunch of heavy ions in RHIC. This cavity is designed to generate a 2 MeV, high charge (several nC), low repetition rate (78 kHz) electron beam using a new fundamental power coupler (FPC) design approach. Structural and thermal analysis, using ANSYS were performed to confirm the FPC structural stability and to calculate the deflection due to heat load from RF power generation. This paper provides an overview of the design, structural and thermal analysis, test results, and FPC tuning drive system for the 112 MHz gun.
BNL, Upton, Long Island, New York, USA
Stony Brook University, Stony Brook, USA
Niowave, Inc., Lansing, Michigan, USA
Fermilab, Batavia, USA
SBU, Stony Brook, New York, USA
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
Efforts to experimentally prove a concept of the coherent electron cooling are underway at BNL. A short 22-MeV linac will provide high charge, low repetition rate beam to cool a single ion bunch in RHIC. The linac will consist of a 112 MHz SRF gun, two 500 MHz normal conducting bunching cavities and a 704 MHz five-cell accelerating SRF cavity. The paper describes the SRF and RF systems, the linac layout, and discusses the project status, first test results and schedule.
BNL, Upton, Long Island, New York, USA
Stony Brook University, Stony Brook, USA
Niowave, Inc., Lansing, Michigan, USA
Fermilab, Batavia, USA
SBU, Stony Brook, New York, USA
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
Efforts to experimentally prove a concept of the coherent electron cooling are underway at BNL. A short 22-MeV linac will provide high charge, low repetition rate beam to cool a single ion bunch in RHIC. The linac will consist of a 112 MHz SRF gun, two 500 MHz normal conducting bunching cavities and a 704 MHz five-cell accelerating SRF cavity. The paper describes the SRF and RF systems, the linac layout, and discusses the project status, first test results and schedule.