RHIC Performance RHIC commissioning and first operation Plans

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RHIC Performance RHIC commissioning and first operation Plans and goals for RUN 2001 Future

RHIC Performance RHIC commissioning and first operation Plans and goals for RUN 2001 Future luminosity upgrade possibilities Thomas Roser Quark Matter 2001 January 15 - 20, 2001

Gold Ion Collisions in RHIC 12: 00 o’clock PHOBOS 10: 00 o’clock RHIC PHENIX

Gold Ion Collisions in RHIC 12: 00 o’clock PHOBOS 10: 00 o’clock RHIC PHENIX 8: 00 o’clock STAR 6: 00 o’clock U-line High Int. Proton Source BAF (NASA) LINAC BRAHMS 2: 00 o’clock m g-2 4: 00 o’clock Design Parameters: Beam Energy = 100 Ge. V/u No. Bunches = 57 No. Ions /Bunch = 1 109 Tstore = 10 hours Lave = 2 1026 cm-2 sec-1 9 Ge. V/u Q = +79 BOOSTER Pol. Proton Source AGS 1 Me. V/u Q = +32 HEP/NP TANDEMS

Parameters and goals for RHIC RUN 2000 l l l l 60 bunches per

Parameters and goals for RHIC RUN 2000 l l l l 60 bunches per ring 5 108 Au/bunch Longitudinal emittance: 0. 3 e. Vs/nucleon/bunch (at injection ) Transverse emittance at storage: 15 p mm (norm, 95%) Initial storage energy: g = 70 [66 Ge. V/nucl. ] (This energy is below the lowest quench of any DX magnet. Full operating current for 100 Ge. V/nucl. reached at end of run) Lattice at interaction regions: b*= 3 m @ 2, 4, 8, and 12 o’clock b*= 8 m @ 6 and 10 o’clock Luminosity: 2 1025 cm-2 s-1 Integrated luminosity: a few (mb) -1

RHIC Injector Performance BOOSTER 1 Me. V/n 100 Me. V/n Au 79+ Au 77+

RHIC Injector Performance BOOSTER 1 Me. V/n 100 Me. V/n Au 79+ Au 77+ AGS 100 Me. V/n 9 Ge. V/n Intensity/RHIC bunch Efficiency Tandem 3. 8 109 Booster Inj. 2. 2 109 58% Booster Extr. 1. 8 109 81% AGS Inj. 0. 9 109 50% AGS Extr. 0. 9 109 95% Total 23% Au 32+ : 1. 1 part. m. A, 530 ms ( 40 Booster turns) TANDEMS Au 1 - Au 12+

RF bunch merging in AGS l l l 4 6 bunches injected from Booster

RF bunch merging in AGS l l l 4 6 bunches injected from Booster Time during AGS cycle l Debunch / rebunch into 4 bunches at AGS injection Final longitudinal emittance: 0. 3 e. Vs/nuc. /bunch Achieved 4 109 Au ions in 4 bunches at AGS extraction AGS circumference

RHIC Pictures (1) Blue and yellow rings Injection arcs to blue and yellow rings

RHIC Pictures (1) Blue and yellow rings Injection arcs to blue and yellow rings

RHIC Pictures (2) Rf storage cavities Installation of final focussing triplets

RHIC Pictures (2) Rf storage cavities Installation of final focussing triplets

Typical closed orbits at injection Before correction After correction

Typical closed orbits at injection Before correction After correction

RHIC beam measurements Measured beam width (red circles) agrees well with prediction (line). Successfully

RHIC beam measurements Measured beam width (red circles) agrees well with prediction (line). Successfully used to diagnose power supply problem.

Tune measurements during acceleration ramp Blue ring Horizontal Storage energy Transition energy Start of

Tune measurements during acceleration ramp Blue ring Horizontal Storage energy Transition energy Start of acceleration Blue ring Vertical

Bunch length [ns] Accelerating a gold bunch in RHIC Injection Transition energy Storage energy

Bunch length [ns] Accelerating a gold bunch in RHIC Injection Transition energy Storage energy

Transition energy crossing RHIC is first superconducting, slow ramping accelerator to cross transition energy:

Transition energy crossing RHIC is first superconducting, slow ramping accelerator to cross transition energy: Slow and fast particles remain in step. increased particle interaction (space charge) short, unstable bunches Cross unstable transition energy with radial energy jump (2000): Transition energy Beam energy DE = 200 Me. V Cross unstable transition energy by rapidly changing transition energy (2001): Transition energy Beam energy Avoids beam loss and longitudinal emittance blow-up

Bringing beams into collision Beam in blue ring Beam in yellow ring 200 ns

Bringing beams into collision Beam in blue ring Beam in yellow ring 200 ns (60 m) Beams in collision at the interaction regions 200 ns (60 m)

Ramp to first collision

Ramp to first collision

RHIC Injection and Acceleration (3. 6 108 Au/bunch)

RHIC Injection and Acceleration (3. 6 108 Au/bunch)

Beam Current [ x 106 ions] Typical Store Blue Beam Current Yellow Beam Current

Beam Current [ x 106 ions] Typical Store Blue Beam Current Yellow Beam Current

Coll. rate / Blue Ions / Yellow Ions [Hz/1018] Specific luminosity Expected: 1. 1

Coll. rate / Blue Ions / Yellow Ions [Hz/1018] Specific luminosity Expected: 1. 1 for PHENIX and BRAHMS 0. 4 for STAR and PHOBOS

Transverse beam emittance during store

Transverse beam emittance during store

Collision rate at detectors Collision rate [Hz] BRAHMS: Lpeak = 3. 3 1025 cm-2

Collision rate at detectors Collision rate [Hz] BRAHMS: Lpeak = 3. 3 1025 cm-2 s-1 Lave = 1. 7 1025 cm-2 s-1 [ s(Au+Au 1 n + 1 n) = 10. 7 b (theor. ) = 9. 1 1. 8 b (meas. , prelim. )]

RUN 2000 integrated Au-Au luminosity BRAHMS during last 6 days: Lave = 0. 8

RUN 2000 integrated Au-Au luminosity BRAHMS during last 6 days: Lave = 0. 8 1025 cm-2 s-1 Availability: 47 %

RUN 2001 Goals l l l Au - Au: 56 bunches per ring with

RUN 2001 Goals l l l Au - Au: 56 bunches per ring with 1 109 Au/bunch Design average luminosity: 2 1026 cm-2 s-1 [60 (mb)-1/week] Design energy/beam: 100 Ge. V/nucl. Design diamond length: s = 20 cm p - p : 56 bunches per ring with 1 1011 p /bunch Average luminosity: 5 1030 cm-2 s-1 [1. 5 (pb)-1/week] Energy/beam: 100 Ge. V (Acceleration to 250 Ge. V) Beam polarization 50 % To reach these goals the following new hardware is being installed: n All remaining IR power supplies n Transition energy pulsed power supplies n 200 MHz storage rf system n All four Siberian snakes n Both RHIC polarimeters

Making short bunches 5 k. V 300 k. V slow fast 36 ns 28

Making short bunches 5 k. V 300 k. V slow fast 36 ns 28 MHz / 300 k. V accelerating cavities 0. 5 - 5 e. Vs sdiam = 0. 36 - 1. 5 m 5 ns 200 MHz / 6 MV storage cavities 0. 7 - 1. 1 e. Vs sdiam = 0. 15 - 0. 20 m

RHIC design luminosity

RHIC design luminosity

Luminosity upgrade possibilities l l l ‘Enhanced’ luminosity possible with existing machine: n Increase

Luminosity upgrade possibilities l l l ‘Enhanced’ luminosity possible with existing machine: n Increase number of bunches to 120 * n Decrease b from 2 m to 1 m Further luminosity upgrades: * n Decrease b further with modified optics n Increase bunch intensity n Decrease beam emittance Last two (three) items are limited by intra-beam scattering and require beam cooling at full energy!

Beam Cooling at RHIC Storage Energy l l Electron beam cooling of RHIC beams:

Beam Cooling at RHIC Storage Energy l l Electron beam cooling of RHIC beams: n Bunched electron beam requirements (prelim. ): 100 Ge. V gold beams: E= 54 Me. V; I= 3 A peak / 10 m. A average n Requires high brightness, high power, energy recuperating superconducting linac, almost identical to Infra-Red Free Electron Laser at TJNAF n Collaboration with BINP, Novosibirsk, on the development of RHIC electron cooling n 10 luminosity increase possible (prelim. ) Stochastic cooling of low intensity gold beams may also be possible.

Summary l l l RUN 2000 RHIC commissioning and first operation was very successful

Summary l l l RUN 2000 RHIC commissioning and first operation was very successful Full design Au luminosity and collisions of polarized protons are planned for RUN 2001 RHIC Au luminosity upgrades: n with existing machine: 4 n with full energy electron cooler: 10 possible