EBIS ARR Jim Alessi May 4- 7, 2010 Technical Overview

2 Outline Motivation Technical Approach Status

EBIS will replace the Tandem beginning in FY2011: Simple, modern, low maintenance Lower operating cost Can produce any ions (noble gases, U, He 3  ) Higher Au injection energy into Booster Fast switching between species, without constraints on beam rigidity Short transfer line to Booster (30 m) Few-turn injection No stripping needed before the Booster, resulting in more stable beams 12 Stripper

NSRL Tandems are the present heavy ion preinjectors for RHIC 860 m long transport line from the Tandems to the Booster EBIS is here

Booster (beams for RHIC and NSRL) IonsHe - U Q / m≥1/6 Current> 1.5 emA Pulse length 10  s (for 1-turn injection) Rep rate5 Hz Output energy2 MeV / u Time to switch species 1 second EBIS Preinjector in lower equipment bay of 200 MeV Linac and 1 st floor addition Average current ~ 250 nA

EBIS Building Addition 2 nd Floor-RF, Instrumentation Electronics and Controls

7 Project history August, 2004: CD-0 Approval – Mission need July, 2005 –Technical, Cost, Schedule, & Management review (NASA & DOE) September, 2005 – DOE CD-1 approval - Alternative Selection and Cost Range May, 2006 – Technical, Cost, Schedule, & Management Review (NASA & DOE) September, 2006 – DOE Independent Project Review September 29, 2006 – DOE CD-2 approval (Performance Baseline), and CD-3 approval (Construction Start) May, 2007 – BHSO Project Review April, 2007 – Start of DOE Construction funds September 19-20, 2007 – DOE/NASA Annual Progress Review January 21-22, 2009 – DOE/NASA Annual Progress Review September, 2010 – Project CD-4 milestone date

8 Test EBIS – full electron current, full energy, full field, half-length prototype

Project Organization

Subsystem responsibilities in C-AD Org Chart ESH&Q Large resource pool. Each task supported by an established group. (1.10 Installation - from many groups)

A 10A electron beam is produced by thermionic emission The electron beam is compressed to mm diameter in a 5T solenoidal magnetic field 1+ ions are trapped electrostatically by electrodes in the solenoid region and stepwise ionized by the electron beam to a high charge state. Ions are then released from the trap, and extracted in a short pulse which is then accelerated by dc and then rf accelerators Principle of EBIS Operation

Electron Beam Ion Source (EBIS) E-Gun Drift Tube Structure Electron Collector Superconducting Solenoid

Ion Injection and Extraction from the RHIC EBIS External ion injection provides the ion species; the EBIS acts purely as a charge breeder. Advantages: 1.One can easily change species and charge state on a pulse to pulse basis 2.There is virtually no contamination or memory effect 3.Several relatively low cost external sources can be connected and maintained independently of the EBIS.

RHIC EBIS during installation

RHIC EBIS Superconducting Solenoid (SCS) Length of the SCS coil: 190 cmTest EBIS: 100cm Magnet field: 5 T Test EBIS: 5T Warm bore inner diameter: 204 mm (8”)Test EBIS: 155mm (6”) Made by ACCEL

High voltage cage installed around EBIS and PS platforms

LEBT, RFQ and matching section before linac

IH Linac Accelerates the beam from 300 keV/u to 2 MeV/u, for injection into Booster

RF Amplifiers in place on the second floor (RFQ, Linac, and three bunchers – all at MHz)

HEBT (EBIS-to-Booster)

Booster–side of ETB complete (except for buncher cavity) Bends the EBIS beam into the Booster injection point.

Validation of Technical Specification CD-4 performance specifications at Faraday cup located between two HEBT 73 degree dipoles for the EBIS pre-injector CD-4 PerformanceOptimum Performance SpeciesFe, AuHe to U Intensity Au +32 /pulse Fe +20 /pulse Au +32 /pulse Fe +20 /pulse He +2 /pulse Charge-to-mass ratio (Q/m)0.162 (Au) (Fe)  0.16, depending on ion species Repetition rateDemonstration of pulsing5 Hz Pulse width10-40 µs Switching time between species Demonstration of switching1 second Output energy2 MeV/amu

Status & Schedule The EBIS source is operating. RFQ was initially tested with beam on the Test EBIS. We are now characterizing the beam at the RFQ output from the RHIC EBIS. The Linac was delivered 4/19, and is in place ~ 1m from its final location. CD-4 date for the project is September, If ARR approval received, we’d like to try helium into Booster/NSRL in June Still missing: Linac not in final location Debuncher cavities C-2 and C-3 not yet in place, but not required for commissioning Magnetic quadrupole triplet after the linac not yet complete Connection of vacuum controls and diagnostics is not completed Some diagnostics (not required for commissioning) are not yet built. Beam stops still to be installed and access controls checked out