High Current Energy Recovery Linac at BNL

Abstract

We present the design and parameters of an energy recovery linac (ERL) facility, which is under construction in the Collider-Accelerator Department at BNL. This R&D facility has the goal of demonstrating CW operation of an ERL with an average beam current in the range of 0.1 -1 ampere and with very high efficiency of energy recovery. The possibility of a future upgrade to a two-pass ERL is also being considered. The heart of the facility is a 5-cell 703.75 MHz super-conducting RF linac with strong Higher Order Mode (HOM) damping. The flexible lattice of the ERL provides a test-bed for exploring issues of transverse and longitudinal instabilities and diagnostics of intense CW electron beams. This ERL is also perfectly suited for a far-IR FEL. We present the status and plans for construction and commissioning of this facility. ERL R&D PROGRAM AT BNLThe ERL R&D program is pursued by the Collider Accelerator Department at BNL as an important stepping-stone for a 10-fold increase of the luminosity of the Relativistic Heavy Ion Collider (RHIC) [1] using relativistic electron cooling [2] of gold ion beams with energy of 100 GeV per nucleon. Furthermore, the ERL R&D program extends toward the possibility of using 10-20 GeV ERL for a future electron-hadron/heavy ion collider, eRHIC [3]. Fig.1 The layout of the R&D ERL facility in the bay of Bldg. 912 at BNL. The bay is equipped with an overhead crane. The facility has a control room, two service rooms and a shielded ERL cave. The control room is located outside of the bay in a separate building. The single story house is used for a high voltage power supply for 1 MW klystron. The two-story unit houses a laser room, the CW 1 MW klystron with its accessories, most of the power supplies and electronics

Design and Principles of Linear Accelerators and Colliders

“…Successful operations of high-power FEL drivers stimulated community interest in ERL technology, and there followed numerous proposals and a number of actual systems. These included: FEL drivers: the JLab IR Upgrade FEL [127], ALICE [128], and the JLab UV Demo FEL [129]; test facilities: CEBAF-ER [130], the KEK cERL [131], bERLinPro [132], ER@CEBAF [133], and PERLE [134,135]; and systems associated with nuclear physics facilities: the BNL test ERL, an electron cooler concept [136], MESA [137], and most recently, conversion of the Darmstadt S-DALINAC to an ERL [138].…”

R&D ERL: 5 Cell 704 MHz SRF Cavity

“…The BNL 5 cell accelerating cavity has been designed [1] for use in our high average current Energy Recovery Linac, a proof of principle machine to demonstrate key components necessary for the future upgrades to RHIC [2] as well as applications for future ampere class high current, high brightness ERL programs. The cavity has been tested at greater than 20 MV/m with a Q 0 of 1e 10 , meeting the design specifications for use at full energy in the ERL.…”

Energy Recovery Linac: 5 Cell 704 MHz SRF Cavity

“…The BNL 5 cell accelerating cavity has been designed [1] for use in our high average current Energy Recovery Linac, a proof of principle machine to demonstrate key components necessary for the future upgrades to RHIC [2] as well as applications for future ampere class high current, high brightness ERL programs. The cavity has been tested at greater than 20 MV/m with a Q 0 of 1e 10 , meeting the design specifications for use at full energy in the ERL.…”