ION SOURCES FOR MEIC Vadim Dudnikov Muons, Inc., Batavia, IL Mini-Workshop for MEIC Ion Complex Design, Jefferson Lab. Jan 27, Abstract Ion sources for production of polarized negative and positive light and heavy ions will be considered. Universal Atomic bean ion source can be used for generation of polarized H-, H+, D-, D+, He++, Li +++ ions with high polarization and high brightness. Generation of multicharged ions, injection and beam instabilities will be considered. References: Belov A.S., Dudnikov V.,et. al., NIM A255, 442 (1987). Belov A.S., Dudnikov V.,et al.,. NIM A333, 256 (1993). Belov A.S, Dudnikov V., et. al., RSI, 67, 1293 (1996). Belchenko Yu. I., Dudnikov V., et. al., RSI, 61, 378 (1990) Belov A.S. et. al., NIM, A239, 443 (1985). Belov A.S. et. al., 11 th International Conference on Ion Sources, Caen, France, September 12-16, 2005; A.S. Belov, PSTP-2007, BNL, USA; A.S. Belov, DSPIN2009, DUBNA, Russia; A. Zelenski, PSTP-2007, BNL, USA; DSPIN2009, DUBNA, Russia EIC Design Goals Energy Center-of-mass energy between 20 GeV and 90 GeV energy asymmetry of ~ 10, 3 GeV electron on 30 GeV proton/15 GeV/n ion up to 9 GeV electron on 225 GeV proton/100 GeV/n ion Luminosity up to cm -2 s -1 per interaction point Ion Species Polarized H, D, 3 He, possibly Li Up to heavy ion A = 208, all striped Polarization Longitudinal polarization at the IP for both beams Transverse polarization of ions Spin-flip of both beams All polarizations >70% desirable Positron Beam desirable Yuhong Zhang For the ELIC Study Group Jefferson Lab ELIC Design Goals Energy Wide CM energy range between 10 GeV and 100 GeV Low energy: 3 to 10 GeV e on 3 to 12 GeV/c p (and ion) Medium energy: up to 11 GeV e on 60 GeV p or 30 GeV/n ion and for future upgrade High energy: up to 10 GeV e on 250 GeV p or 100 GeV/n ion Luminosity up to cm -2 s -1 per collision point Multiple interaction points Ion Species Polarized H, D, 3 He, possibly Li Up to heavy ion A = 208, all stripped Polarization Longitudinal at the IP for both beams, transverse of ions Spin-flip of both beams All polarizations >70% desirable Positron Beam desirable Andrew Hutton MEIC: Low and Medium Energy Three compact rings: 3 to 11 GeV electron Up to 12 GeV/c proton (warm) Up to 60 GeV/c proton (cold) MEIC: Detailed Layout polarimetry ELIC: High Energy & Staging Ion Sources SRF Linac p e ee p p prebooster ELIC collider ring MEIC collider ring injector 12 GeV CEBAF Ion ring electron ring Vertical crossing Interaction Point Circumferencem1800 Radiusm140 Widthm280 Lengthm695 Straightm306 StageMax. Energy (GeV/c) Ring Size (m) Ring TypeIP # pepepe Low125 (11)630Warm 1 Medium605 (11)630ColdWarm2 High ColdWarm4 Serves as a large booster to the full energy collider ring ELIC Main Parameters Beam EnergyGeV250/10150/760/560/312/3 Collision freq.MHz499 Particles/bunch10 1.1/3.10.5/ /2.91.1/60.47/2.3 Beam currentA0.9/2.50.4/ / / /2.7 Energy spread10 -4 ~ 3 RMS bunch lengthmm Horiz.. emit., norm.mm0.7/510.5/430.56/850.8/750.18/80 Vert. emit. Norm.mm0.03/20.03/ /170.8/750.18/80 Horizontal beta-starmm Vertical beta-starmm5 Vert. b-b tune shift/IP 0.01/ / / / /.013 Laslett tune shiftp-beam Peak Lumi/IP, cm -2 s High energy Medium energy Low energy Achieving High Luminosity MEIC design luminosity L~ 4x10 34 cm -2 s -1 for medium energy (60 GeV x 3 GeV) Luminosity Concepts High bunch collision frequency (0.5 GHz, can be up to 1.5 GHz) Very small bunch charge ( 3.0 mA) Q/m 0.16, depending on ion species Repetition rate5 Hz Pulse width s Switching time between species1 second Output emittance (Au 32+ ) < 0.18 mm mrad,norm,rms Output energy17 keV/amu LEBT/Ion Source Region ECR 28 GHz Heavy Ion Source Region 290 MY BNL RFQ Pre-injector Development History of Surface Plasma Source development ( J.Peters, RSI, v.71, 2000) Invention formula: Enhancement of negative ion production comprising admixture into the discharge a substance with a low ionization potential, such as cesium. Cesium patent V. Dudnikov. The Method for Negative Ion Production, SU Author Certificate, C1.H013/04, No , Application filed at 10 Mar., 1972, granted 21 Sept, Production of highest polarization and reliable operation are main goals of ion sources development in the Jefferson Lab Development of Universal Atomic Beam Polarized Sources (most promising, less expensive for repeating). It is proposed to develop one universal H-/D-/He ion source design which will synthesize the most advanced developments in the field of polarized ion sources to provide high current, high brightness, ion beams with greater than 90% polarization, good lifetime, high reliability, and good power efficiency. The new source will be an advanced version of an atomic beam polarized ion source (ABPIS) with resonant charge exchange ionization by negative ions, which are generated by surface-plasma interactions. Ion Sources for Electron Ion Colliders Optimized versions of existing polarized ion sources (ABPS and OPPIS) and advanced injection methods are capable to delivery ion beam parameters necessary for high luminosity of EIC. Combination of advanced elements of polarized ion source and injection system are necessary for reliable production of necessary beams parameters. Advanced control of instabilities should be developed for support a high collider luminosity. History of e-p instability observation From F. Zimmermann report Was presented in Cambridge PAC67 but only INP was identified as e-p instability Simulation of electron cloud accumulation and e-p instability development (secondary ion/electron emission); Penning discharge Plasma generators for space charge compensation 1- circulating proton beam; 2- magnetic poles; 3- filaments, (field emission) electron sources; 4- grounded fine mesh; 5- secondary emission plate with a negative potential. Electrons e emitted by filaments 3 are oscillating between negative plates 5 with a high secondary emission for electron multiplication. A beam density and plasma density must be high enough for selfstabilization of e-p instability (second threshold). Secondary ion accumulation is important for selfstabilization of e-p instability. Beam accumulation with a plasma generator on and off on off on