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  • The Relativistic Heavy Ion Collider high-intensity polarized H- ion source A.Zelenski, G.Atoian, D.Raparia, J.Ritter, D.Steski Brookhaven National Laboratory ICIS 2015, August 28, 2015Optical pumping polarization techniqueCharge-exchange collisionsHigh-brightness atomic beam sourceHe-ionizer cellSodium-jet ionizer cellSummary

  • Summary

    The old RHIC OPPIS based on ECR primary proton source retired after successful operation in Runs 2000-2012.

    The new source with atomic beam hydrogen injector and He-ionizer was developed in 2010-12 and commissioned for operation in Run-2013.

    It produces significantly higher brightness primary proton beam which resulted in higher polarized beam intensity and polarization delivered for injection to Linac-Booster-AGS-RHIC accelerator chain.

    Practically all OPPIS systems were modified (in addition to the ECR-source): a new superconducting solenoid; new He-ionizer cell with a pulsed He-injection and new pulsed electro-magnetic gas valve; beam energy separation system developed for un-polarized residual beam suppression; new vacuum system with turbo-molecular pumps for He-pumping; laser control, diagnostics and transport systems.

  • The RHIC OPPIS upgrade with atomic hydrogen injector, Run-2013-15BNL - BINP, Novosibisk -INR, Moscow collaboration

  • STARPHENIX AGS, 24GeVLINACBOOSTER, 2.5 GeVPol. H- ion sourceSpin RotatorsSiberian Snakes200 MeV polarimeterRHIC pC CNI polarimeters RHICAbsolute H-jetpolarimeter L max = 1.6 1032 s-1cm-2 50 < s < 510 GeVAGS pC CNI polarimeterPolarization facilities at RHIC

  • OPPISLINACBoosterAGSRHIC(2.0-2.5) 1011 p/bunch1.0 mA x 300us181011 polarized H- /pulse.9.0 1011 polarized H- /pulse at 200 MeVroutinely in Run-15(2.5-3.0) 1011 protons /pulse at 2.3 GeV~1.81011 p/bunch, P~60-65% at 100 GeV P ~ 58% at 255 GeV RHIC Polarized beam in Run 2013-15It is expected, that use of Electron Lenswill allow increase of the bunch intensity to ~2.51011 p/bunch.

  • What can we learn about swiss watches from watches collisions?Actually a lot!In particular, if protons are polarized!

  • Intermediate bozons W - can be produced directly in electroweak processes in collisions of polarized proton beams of a 250 GeV energy at RHIC.

    In this case parity-violation can be as large as 50% and spin-correlation can be used for studies of different flavor quark contribution to the proton spin.

  • SPIN -TRANSFER POLARIZATION IN PROTON-Rb COLLISIONSRb+H+H+Proton source

    Laser-795 nmOptical pumpingRb: NL(Rb) ~1014 cm-2 SonatransitionIonizercellH-Laser beam is a primary source of angular momentum:10 W (795 nm) 41019 h/sec 2 A, H0 equivalent intensity.Supperconducting solenoid 25 1.5 kG fieldCharge-exchange collisions: ~10-14 cm2Na-jet ionizer cell:NL(Na)~ 31015 cm-2 Electron to proton polarization transferECR-29 GHz + source~50 mA, 2.8keVRb+

  • Optical Pumping polarization technique. A. Kastler, Nobel prize 19665S1/25P1/2 = 795 nm Circularly Polarized lightMJ = -1/2MJ = +1/2nLJ1.56 eVrelaxationOptical pumping application is limited by available laser power!?Recent progress in laser technology is very promising for new applications.MJ = +1/2MJ = -1/2

  • Pulsed OPPIS with the atomic hydrogen injector at INR, Moscow, 1982-1990. First generationAtomic H0 injectorHelium ionizer cell~80% ionizationefficiency.Lamb-shift polarimeterH- current- 0.4mAH+ current- 4.0 mA, P=65%, 1986

  • New generation OPPIS with atomic H0 injectorAtomic HinjectorHe-cellH-High-brightness proton beam inside strong 2.5 T solenoid field produced by atomic H beam ionization in the He-gas ionizer cellThe proton beam intensity is about 1.0 A !

  • Hydrogen atomic beam ionization efficiency in the He- cell10 keV80%H0 + He H+ + He + e

  • Fast Atomic Beam Source, BINP, Novosibirsk, 2012Plasmatron4-grid protonextraction systemH2 Neutralization cell~ 3.5 AequivalentH0 beamFABS produces 200-300 mA equivalent H0 beam intensityWithin the Na-jet ionizer acceptance.

  • FABS 4-grid spherical Ion Optical System 3-5 A of proton beamAt 6-8 keVenergy1820 holes , 1.0 mm in diameter

  • FABS and neutralizer cell.

  • Neutral hydrogen beam intensity profile at 250 cm distance from the source.FWHM~ 20 mm

  • Residual un-polarized H0 beam component suppression by the energy separationH+(70%)H0(6.5 keV)H0(2.5 keV)-4.0 kV-4.1 kV-4.1 kVH0(6.5keV)He-ionizer cellRb -cellH0(30%)DecelerationH0 + He H+ + He + e-2-3 kV+0.1kV

  • He-ionizer cell and 3-grid energy separation system.He-pulsedvalve3-grid beamdecelerationsystem

  • Electro-magnetic valve operation principle.Force to the conducting plate in the (high ~ 3 T) magnetic field.

    For I=100 A, L=5 cm, F=15 N).IBF

  • New OPPIS with atomic H0 injector layout, 2013Rb-cellH+H0H+H0H-H2HeRbNaCP1Na-jetcellAtomic HinjectorHe-ionizercellNeutralizer H2-cellTMP1Rb-cellSonatransition

  • H- yield vs. H0 beam energy.

    Chart4

    7

    9

    9

    8.4

    7.3

    6.1

    4.9

    3.8

    2.9

    2

    Beam energy, keV

    H- ion yield, %

    Sheet1

    21.213

    2.52.528

    33.741

    3.54.556

    4675

    4.57100

    58.8129

    5.59.2150

    69.5190

    712240

    21213

    2.52528

    33741

    3.54556

    46075

    4.570100

    589129

    5.592150

    695190

    7120240

    0.47

    19

    29

    38.4

    47.3

    56.1

    64.9

    73.8

    82.9

    102

    Sheet1

    Beam energy, keV

    H- Beam current ,mA

    Sheet2

    Beam energy, keV

    Beam current, mA

    Sheet3

    Beam energy, keV

    Beam current, mA

    Beam energy, keV

    H- ion yield, %

  • Sodium-jet ionizer cellReservoir operational temperature. Tres. ~500 .Nozzle Tn ~500 .Collector- Na-vapor condensation: Tcoll.~120Trap- return line. T ~ 120 180 .Transversal vapor flow in the N-jet cell.Reduces sodium vapor losses for 3-4 ordersof magnitude, which allow the cell aperture increase up to 3.0 cm .Nozzle500deg.CCollector~150 deg.CReservoir~500 deg.CNL ~21015 atoms/cm2L ~ 2-3 cm

  • H- beam acceleration to 35 keV at the exit of Na-jet ionizer cell Na-jet cell is isolated and biased to 32 keV. The H- beam is accelerated in a two-stage acceleration system.-32 kVH-35 keV

    39 keV

    -28 keV-15 keV3 keV7 kevH0

  • H- beam acceleration to 35 keV at the exit of Na-jet ionizer cell. Na-jet cell is isolated and biased to 32 keV. The H- beam is accelerated in a two-stage acceleration system.-32 kVH-

    35 keV-28 keV-15 keV

  • Low Energy Beam Transport line.Variable collimatorIn DB2 to improveEnergy resolution.Lamb Shift PolarimeterFC435.0 keVFC-Tk1,750keVOPPIS23.7 deg benderRFQ

  • Energy separation of decelerated (polarized) H- ion beam in LEBT. 31.5 kV31.5 + (7.5 4.0) = 35 keV1400/30=47

    Chart2

    0.124

    0.224.2

    0.324.4

    0.424.6

    0.624.8

    0.725

    0.825.2

    1.125.4

    1.325.6

    1.625.8

    1.826

    2.126.2

    2.326.4

    2.526.6

    2.626.8

    2.727

    2.827.2

    327.4

    327.6

    327.8

    2.928

    2.828.2

    2.728.4

    2.528.6

    2.428.8

    2.229

    229.2

    1.729.4

    1.229.6

    0.9329.8

    0.630

    0.4230.2

    0.230.4

    0.230.6

    0.1530.8

    0.1231

    0.131.2

    0.0631.4

    0.0431.6

    0.0331.8

    0.0232

    0.01532.2

    0.01532.4

    0.01532.6

    0.0132.8

    0.0133

    33.233.2

    33.433.4

    33.633.6

    33.833.8

    350.002

    34.80.005

    34.60.007

    34.40.025

    34.20.08

    340.12

    33.80.2

    33.60.3

    33.40.4

    33.20.5

    330.7

    32.80.8

    32.61

    32.41.05

    32.21.1

    321.2

    31.81.25

    31.61.3

    31.51.4

    31.41.3

    31.21.3

    311.3

    30.81.3

    30.61.25

    30.41.2

    30.21.15

    301.03

    29.81.05

    29.61

    29.40.9

    29.20.8

    290.75

    28.80.7

    28.60.65

    28.40.65

    28.20.65

    280.7

    27.80.7

    27.60.75

    27.40.8

    27.20.8

    270.8

    26.80.8

    26.60.8

    26.40.8

    26.20.8

    260.7

    25.80.65

    25.60.6

    25.40.5

    25.20.45

    250.4

    24.80.35

    24.60.3

    24.40.25

    24.20.25

    240.2

    23.80.15

    23.60.12

    23.40.08

    23.20.06

    230.03

    22.80.015

    22.60.005

    Acceleration voltage, kV

    H- ion beam current, mA

    Sheet1

    240.02

    24.50.07

    250.2

    25.50.4

    260.8

    26.51.3

    271.8

    27.52.2

    282.5

    28.52.6

    292.6

    29.52.4

    302

    30.51.5

    311

    31.50.5

    320.3

    32.50.1

    25.50.07

    260.2

    26.50.5

    271

    27.51.9

    282.5

    28.53

    293.3

    29.53.3

    303.2

    30.52.8

    312

    31.51.2

    320.5

    32.50.1

    3480

    3980

    4790

    55100

    60120

    65130

    71150

    75180

    80200

    89300

    94370

    97450

    101500

    104560

    106600

    I

    26300

    26.2380

    26.4400

    26.6400

    26.8420

    27450

    27.2450

    27.4450

    27.6450

    27.8450

    28470

    28.2470

    28.4470

    28.6470

    28.8480

    29500

    29.2470

    29.4420

    29.6380

    29.8320

    30320

    30.2330

    30.4360

    30.6400

    30.8400

    31400

    31.2410

    31.4410

    31.6400

    31.8400

    32400

    32.2390

    32.4360

    32.6330

    32.8300

    33290

    33.2280

    33.4240

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