Application of Cooling Methods to NICA Project · Booster KRION + “New” HILAC Nuclotron...

August 31, 2009 COOL Workshop, Lanzhou, China 1

A.Smirnov, Application of Cooling Methods to NICA ProjectApplication of Cooling Methods to NICA Project

Application of Cooling Methods toApplication of Cooling Methods to NICA NICA ProjectProject( ( NNuclotronuclotron--basedbased IIonon CColliderollider ffAAcilitycility ))

AA..SmirnovSmirnov,, EE..AhmanovaAhmanova, V, V..BykovskyBykovsky, A, A..KobetsKobets, , DD..KrestnikovKrestnikov,, II..MeshkovMeshkov, R, R..PivinPivin, A, A..RudakovRudakov, , AA..SidorinSidorin, S, S..YakovenkoYakovenko (JINR, Dubna, Russia)(JINR, Dubna, Russia)

JJüürrgengen DietrichDietrich (FZJ, (FZJ, JJüülichlich))

TakeshiTakeshi KatayamaKatayama (GSI, (GSI, DarmstadtDarmstadt))



The Project goals formulated are the following:1a) Heavy ion colliding beams 197Au79+ x 197Au79+ at

√sNN = 4 ÷ 11 GeV (1 ÷ 4.5 GeV/u ion kinetic energy ) at

Laverage= 1⋅1027 cm-2⋅s-1 (at √sNN = 9 GeV)

1b) Light-Heavy ion colliding beams of the energy range and luminosity

2) Polarized beams of protons and deuterons:p↑p↑ √sNN = 12 ÷ 25 GeV (5 ÷ 12.6 GeV kinetic energy )

d↑d↑ √sNN = 4 ÷ 13.8 GeV (2 ÷ 5.9 GeV/u ion kinetic energy )

Development of the NICA Conceptand Technical Design Report



NICA scheme & layout

2.3 m

4.0 m

Booster

Synchrophasotron yoke

Nuclotron

Existing beam lines(solid target exp-s)

Collider

C = 251 m

MPD

Spin Physics Detector (SPD)



NICA scheme & layout (Contnd)

“Old” Linac LU-20

KRION + “New” HILACBooster

Nuclotron

Collider MPD

SPD Beam dump



Booster (25 Tm)1(2-3) single-turn injection,

storage of 2 (4-6)×109,acceleration up to 100 MeV/u,

electron cooling,acceleration

up to 600 MeV/u

Nuclotron (45 Tm)injection of one bunch

of 1.1×109 ions,acceleration up to 1÷4.5 GeV/u max.

Collider (45 Tm)Storage of

17 (20) bunches × 1⋅109 ions per ring at 1÷4.5 GeV/u,

electron and/or stochastic cooling

Injector: 2×109 ions/pulse of 197Au32+

at energy of 6.2 MeV/u

IP-1

IP-2

Two superconductingcollider rings

Operation regime and parameters

Stripping (80%) 197Au32+ ⇒ 197Au79+

2х17 (20)injection cycles

Bunch compression (RF phase jump)



0.03ΣLoss = 40%Nextr= 109

0.51⋅10-30.253500At extraction

0.0075<121.5E-40.253500After acceleration

0.051<203.13.4E-40.89594Injection (after stripping)

0.00853.13.2E-40.89600At extraction

0.016<107.173.8E-42.45100After cooling (h=1)

0.0221061.3E-3106.2Injection (after bunching on 4th

harmonics

Space charge

ΔQ

Intensityloss,%

lbunchm

Δp/pεunnormπ⋅mm⋅mrad

E MeV/u

Stage

Bunch parameters dynamics in the injection chainOperation regime and parameters



0

0,5

1

1,5

2

0 2 4 6

Time Table of The Storage Process

2.1. Operation regime and parameters

B(t)

, arb

. uni

ts0

0,5

11,5

2

0 2 4 6

Booster magnetic field

B(t)

, arb

. uni

ts

Nuclotron magnetic field

t, [s]

t, [s]

electroncooling

1 (2-3) injection cycles,electron cooling (?)

Extraction, stripping to 197Au79+

bunch compression,extraction

injection



Electron cooling in BoosterParameters of electron cooling system

5×10-4Misalignment of ion and electron beams axes

200 / 0.5Electron beam temperature long/trans, meV

1.0Electron beam current, A

14Initial bunch length, m

10RF voltage, kV

5×10-4Initial momentum spread

1.5Initial transverse emittance, π mm mrad

2×109Particle number

197Au32+Ion kind

100Ion energy, MeV



Layout of Booster Electron Cooler

electron gun

collector

cryostat

superconducting solenoids

“warm” solenoids



Electron gun and collector

Collector Electron gun



Electron cooling in BoosterSimulation of e-cooling process

Evolution of the bunched ion beam parameters during the cooling process with misalignment angle of 5×10-4. a) horizontal (red) and vertical (blue) emittances, b) ion momentum spread, c) longitudinal emittance.

a) c)b)



Beam Profiles withMisalignment of Electron Beam Axis

Ion beam density distribution after 2 seconds of the cooling: a) horizontal (red) and vertical (blue) profiles, b) transverse plane and c) horizontal transverse phase space of the cooled ion beam

a) c)b)



00.20.40.60.8

11.21.41.61.8

0.E+00 2.E-04 4.E-04 6.E-04 8.E-04 1.E-03

misaligment, rad

cool

ing

time,

sec

00.20.40.60.811.21.41.61.8

emitt

ance

, pi m

m m

rad

cooling timeemittance

The dependence of the cooling time and transverse emittance after the cooling process on the misalignment angle between electron and ion beams axes; “the cooling time” is defined as a time interval when the longitudinal emittance decreases from 7.5 eV⋅s to 2.5 eV⋅s



2 x 4 Number of vertical dipoles per ring24 / 3.0 mNumber of dipoles / length

4 x 8.8 mShort straight sections: number / length,2 x 48.0 mLong straight sections: number / length

29.0Quad gradient (max), [ T/m ]

4.0Dipole field (max), [ T ]

32 / 0.4 mNumber of quads / length

1.0 ÷ 4.56Ion kinetic energy (Au79+), [GeV/u]

251.52Ring circumference, [m]45.0Bρ max [ T⋅m ]

ColliderGeneral Parameters



0Beam crossing angle at IP

9 mFree space at IP (for detector)

0.0 / 0.0Dx / Dy in IP, m

0.5 / 0.5βx_min / βy_min in IP, m

5.9 / 0.2Dx_max / Dy_max in FODO period, m

5.26 / 5.17Betatron tunes Qx / Qy

102100

RF system harmonics amplitude, [kV]

100 ÷ 10Vacuum, [ pTorr ]

4.95 / 3.012 GeV/uTransition energy, γ_tr / E_tr

16.8 / 15.2βx_max / βy_max in FODO period, m

-12.22 / -11.85Chromaticity Q’x / Q’y

Collider General parameters (Contnd)



1717Number of bunches per ring1E91E9Ion number per bunch

50650IBS growth time, s0.00510.0026Beam-beam parameter ξ0.0470.056Incoherent tune shift ΔQbet

1.1E270.75E26Luminosity per one IP, cm-2·s-10.30.3Rms bunch length, m

1E-31E-3Rms momentum spread0.25 3.8Rms unnormalized beam emittance, π·mm mrad

3.51.0Energy, GeV/u

Collider General parameters (Contnd)

Collider beam parameters and luminosity



Electron cooling system of the ColliderMax electron energy, MeV 2.5Max electron current, A 0.5Solenoid magnetic field, T 0.3 - 2“Magnetized” electron beamSolenoid type: “warm” at acceleration/deceleration columns

superconducting at transportation and cooling sectionsHV generator: Dynamitron type

6 m

3 m

Under development in collaboration - All-Russian Institute for

Electrotechnique (Moscow)- IKP (FZ-Juelich)

- Budker INP (Novosibirsk)



Electron cooling in ColliderParameters of electron cooling system

1.0Beam lifetime due to recombination, hour

5.0Longitudinal electron temperature meV

50.0Transverse electron temperature, eV

20Beta functions in cooling section, m

2×10-5Magnetic field inhomogeneity in cooling section

2.0Magnetic field in cooling section, T

0.5Electron beam radius, cm

0.5Electron beam current, A

6.0Effective cooler length, m2.4Maximum electron energy, MeV



Simulation of e-cooling process

luminosity

emittances (normalized)

momentum spread (GeV/c)

profiles

invariants

core

tail



Longitudinal stochastic cooling in Collider(Palmer method)

1. Particle: 197Au79+, 3.5 GeV/u, Gamma=4.76, Beta=0.978 2. Ring circumference: 225 m 3. Number of particles: 1e9 ions/bunch. 4. Achieved Bunch length: ~ 0.12 m, 0.4 nsec (1 sigma)5. Initial (injected) momentum spread : 1.5e-3 (1 sigma)6. Initial (injected) bunch length : 0.7 m, 2.5 nsec (1 sigma)7. Ring slipping factor: 0.02328. Time of flight from PU to Kicker: 0.4 e-6 sec 9. Dispersion at PU: 5.0m, Dispersion at Kicker=0.0 m 10. Band width: 2-4 GHz11. Number of PU, and Kicker=128 12. Pickup Impedance=50 Ohm13. Gain=90 dB. 14. Atmospheric Temperature: 300 K, Noise Temperature=40 K15. RF Voltage = 10 kV, (Harmonic Number=102)16. Transverse emittance = 0.3 Pi mm.mrad (constant)



Simulation of s-cooling process

50 sec



Longitudinal Stochastic cooling for Nuclotron

kicker

pick up



GSI/FAIR (Darmstadt)SC dipoles for Booster/SIS-100SC dipoles for Collider

NICA Collaboration

Budker INP (Novosibirsk)Booster RF systemBooster electron coolingCollider RF systemCollider SC magnets(expertise)HV electron cooler for colliderElectronics

IHEP (Protvino)Injector Linac

IKP (FZ-Jűlich)HV Electron coolerStoch. cooling

Fermilab (Batavia)HV Electron coolerStoch. cooling

All-Russian Institute for ElectrotechniqueHV Electron cooler (Moscow)

Corporation “Powder Metallurgy” (Minsk, Belorussia)Technology of TiN coating of vacuum chamber walls for reduction of secondary emission

BNL (Upton)Electron &Stoch. Cooling

ITEP (Moscow). Beam Dynamics

Application of Cooling Methods to NICA Project · Booster KRION + “New” HILAC Nuclotron...

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