the relativistic heavy ion collider high-intensity polarized h - ion source the relativistic heavy...
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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