Документ взят из кэша поисковой машины. Адрес оригинального документа : http://nuclphys.sinp.msu.ru/persons/VEKSLER/veksler100/reports/reports/Meshkov_OctVeksler_Sem_UU.pdf Дата изменения: Wed Mar 25 16:36:26 2009 Дата индексирования: Tue Oct 2 00:50:44 2012 Кодировка: Поисковые слова: m 5

Nuclotron-based Ion Collider fAcility
I.N.Meshkov for NICA Working Group

Scientific Workshop Dedicated to The Centenary of V. I. Veksler's Birth and the 50th Anniversary of Commissioning the Synchrophasotron
Dubna, October 10-12, 2007
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Contents

1. Introduction: "The Basic Conditions" for
the Project development and some consequences 2. NICA scheme 3. Collider general parameters 4. NICA layout 5. Collider luminosity limitations 6. Collider ring optics and lattice functions 7. Injector: Ion Source + Preinjector + Linac 8. Booster 9. Cost estimate Conclusion 10. Project work organization 11. Project milestones 12. News from RHIC 13. NICA again
I.Meshkov, NICA Project Veksler's Century Workshop
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Dubna, October 10-12, 2007


1. Introduction: "The Basic Conditions" for the Project development and some consequences
Development of the JINR basic facility for generation of intense heavy ion and polarized nuclear beams aimed at searching for the mixed phase of nuclear matter and investigation of polarization phenomena at the collision energies up to sNN = 9 GeV/u, i.e.
238U

x

238U *)

in the energy range 1 В 3.5 (5) GeV/u.

The required average luminosity is Laverage= 11027 cm-2s-1
*)

Changed to Au x Au recently
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I.Meshkov, NICA Project

Veksler's Century Workshop

Dubna, October 10-12, 2007


1. Introduction: "The Basic Conditions" for the Project development
and some consequences (Contnd)

The Conditions: 1. Minimum of R & D 2. Application of existing experience 3. Co-operation with experienced research Centers 4. Cost ­ as low as possible 5. Realization time ­ 4 ­ 5 years
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I.Meshkov, NICA Project

Veksler's Century Workshop

Dubna, October 10-12, 2007


1. Introduction: "The Basic Conditions" for the Project development
and some consequences (Contnd)

The Choice of Uranium nuclei as the basic particle for the project development allows us to meet all the necessary conditions for realization of an ion-ion collider in a wide range of colliding nuclei

from p to U.

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I.Meshkov, NICA Project

Veksler's Century Workshop

Dubna, October 10-12, 2007


1. Introduction: "The Basic Conditions" for the Project development
and some consequences (Contnd)

The Concequences: Choice of an existing building for dislocation of the collider Collider perimeter is limited by ~ 250 m Luminosity High beam intensity, multibunch regime, low beta-function in Interaction Point,

.........................................................
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I.Meshkov, NICA Project

Veksler's Century Workshop

Dubna, October 10-12, 2007


2. NICA Scheme
Injector: 2в109 ions/pulse of MeV/u
238

U

32+

at energy 5 Booster (25 Tm) 5 single-turn injections, storage of 8в109, acceleration up to 50 MeV/u, electron cooling, acceleration up to 440 MeV/u Stripping (40%)
238

Collider (45 Tm) Storage of 20 bunches в 2.5109 ions per ring at 3.5 GeV/u max., electron and/or stochastic cooling

U

32+ 238

U

92+

IP-1

Two superconducting collider rings

IP-2

Nuclotron (45 Tm) injection of one bunch of 3в109 ions, acceleration up to 4.5 GeV/u max.

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I.Meshkov, NICA Project

Veksler's Century Workshop

Dubna, October 10-12, 2007


2. NICA scheme (Contnd)

2 x 31010 ions of 238U92+

Time Table of The Storage Process
KRION
3.5 GeV/u

RFQ

LINAC

Booster Nuclotron Collider
electron cooling

Eion/A
450 MeV/u
5 cycles of injection

50 MeV/u 5 MeV/u
238

10 injection cycles of 3109 ions 238U92+ per cycle

300 keV/u 20 keV/u
238

U

92+

8s

0.1s 5s 6s

8s

2 min

t
U
32+

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I.Meshkov, NICA Project

Veksler's Century Workshop

Dubna, October 10-12, 2007


3. Collider General Parameters
Ring circumference, [m] B min/max (U92+), Dipole field, [T] [ Tm ] Ion kinetic energy, [GeV/amu] Long straight sections number / length, [m] Short straight sections number / length, [m] Vacuum, RF [ pTorr ] harmonics amplitude, [kV] 251.2 14.6/45 1.0 В 4.36 1.95 В 5.5 2 x 48.3 4 x 9.66 100 В 10 70 150

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Veksler's Century Workshop

Dubna, October 10-12, 2007


3. Collider General Parameters (Contnd)

Beam parameters and luminosity
Particle number per bunch, Bunch length, m Bunch number, nbunch Interbunch distance, [m] Horizontal emittance, Momentum spread, IBS life time [sec] Beta function at interaction point, * Laslett tune shift, Q Beam-beam parameter Peak luminosity (at 3.5 GeV/u), [cm-2s-1] Average luminosity (at 3.5 GeV/u), [cm-2s-1]
I.Meshkov, NICA Project Veksler's Century Workshop

Nion/bunch

3.0в109 0.33 14 8.5 0.7 0.001 50 (to be increased) 0. 5 0.05 0.009 2в10
27 27

To cool,mrad]not to cool? or [ mm
p/p

(1В1.5)в10

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4. NICA Layout
Booster Krion & Linac Existing beam lines (solid target exp-s)

Nuclotron Collider C = 251.2 m

The second possible detector Averaged luminosity 1.31027 cm-2s-1 (238U92+ x 238U
92+

)
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I.Meshkov, NICA Project

Veksler's Century Workshop

Dubna, October 10-12, 2007


5. Collider Luminosity Limitations
1) Multibunch regime ­ storage and exchange "bunch by bunch". 2) Bunch number is limited by parameters of the injection/extraction system: at realistic kicker pulse duration ~ 100 ns one can have 10 bunches/ring if Ccollider = 250 m. 3) Bunch intensity is limited by space charge effects:
"Lasslett tune shift" Q = 0.05 for N
ion/bunch

=3109, l

bunch

= 0.33 m

..........................................................................................................................
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Beam-beam effect =0.009 at the same bunch parameters ,

I.Meshkov, NICA Project

Veksler's Century Workshop

Dubna, October 10-12, 2007


5. Collider Luminosity Limitations (Contnd)

Ion storage ­ equilibrium regime (exchange of bunches "one by one") ­ bunch emittanse growth:
ln()
Bunch 1A Tinj 2Nbunch * T
inj

4) Ion life time and average luminosity

Average luminosity:
t

L=L

peak

(),
life

Bunch 1B

= Tinj/
t
1 1 0.8 0.6 0.4 0.2 0 0 0 0 0.02 0.04

Bunch 2A

L() t
( ) _R ( )

Bunch 2B

t
Bunch 3A

t
Bunch 3B

(t ) =
(t ) =

min

exp t /

0.06

0.08

0.1 0.1

(

life

)

min

1+ t /

life

I.Meshkov, NICA Project

Veksler's Century Workshop

t

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5. Collider Luminosity Limitations (Contnd)

5) Min -function and hourglass effect
Optics & lattice function at IP

At lbunch = 2 x 16.5 cm and * = 50 cm we have
L L
peak





min max

~


min

+

min 2 l bunch

~ 0.9



min

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I.Meshkov, NICA Project

Veksler's Century Workshop

Dubna, October 10-12, 2007


5. Collider Luminosity Limitations (Contnd)

6) Collider beam bunch length

l

bunch

= 33 cm

How to get it?

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I.Meshkov, NICA Project

Veksler's Century Workshop

Dubna, October 10-12, 2007


5. Collider Luminosity Limitations (Contnd)

6) Collider beam bunch length

The scenario of the short bunch formation: 1/ from injector to booster, adiabatic capture in acceleration, 2/ from booster to Nuclotron, adiabatic capture in acceleration, 3/ RF phase jump and "overtun" in phase space by "fast" increase of RF voltage, 4/ short bunch from Nuclotron to collider.

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Veksler's Century Workshop

Dubna, October 10-12, 2007


5. Collider Luminosity Limitations (Contnd)

6) Collider beam bunch length (Contnd) Adiabatic capture and acceleration in Nuclotron A. Eliseev

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Veksler's Century Workshop

Dubna, October 10-12, 2007


5. Collider Luminosity Limitations (Contnd)

6) Collider beam bunch length (Contnd)
Nuclotron, after acceleration and before "overturn"

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Veksler's Century Workshop

Dubna, October 10-12, 2007


5. Collider Luminosity Limitations (Contnd)

6) Collider beam bunch length (Contnd)
RF Phase and (later) amplitude jumps ­ bunch "overturn" in phase space

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Veksler's Century Workshop

Dubna, October 10-12, 2007


6. Collider ring optics and lattice functions

Superperiod and a bit longer...

Optics & lattice function at IP

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I.Meshkov, NICA Project

Veksler's Century Workshop

Dubna, October 10-12, 2007


7. Injector: Ion Source + Preinjector + Linac

d В 238U 20 В 5 MeV/u

32+

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I.Meshkov, NICA Project

Veksler's Century Workshop

Dubna, October 10-12, 2007


7. Injector: Ion Source + Preinjector + Linac (Contnd)

Magnetic field 1.5 3.0 (6.0) T, Design parametersTof KRION-6T
Ion kind Electron energy, E
e

Ion Source

ion number increase

Au30+ (U30+) 25 keV 6в1019 cm-2

Ionization factor, j Dependence of ion number on magnetic field Ionization time, Repetition rate Pulse width, t Ion number per pulse, N Ion current, Ii
I.Meshkov, NICA Project
i

Version 1

Version 2

Version 3

N

0.03 s 30 Hz 8в10-6 s 1в10
9

e/i

B

N

0.015 s 60 Hz 8в10
-6

e/i

B

2

N

0.0075 s 120 Hz 8в10-6 s 4в10
9

e/i

B

3

s
9

2в10

0.6 mA
Veksler's Century Workshop

1.2 mA

2.4 mA
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Dubna, October 10-12, 2007


7. Injector: Ion Source + Preinjector + Linac (Contnd)

Ion Source (Contnd)

Ion Sources comparison Ion source Peak ion current, mA Pulse duration, s Ions per pulse Ions per sec Norm. rms emittance Repetition rate, Hz KRION, Au30+ 1.2 8 2в109 2.5x10 60
8

ECR, Pb27+ 0.2 200 1в1010 5x107 0.15В0.3 30

0.15В0.3

Crucial parameter: Ions per sec! Thus, KRION has very significant advantage!
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I.Meshkov, NICA Project

Veksler's Century Workshop

Dubna, October 10-12, 2007


7. Injector: Ion Source + Preinjector + Linac (Contnd)

Preinjector + Linac
Injector concept
KRION suspended up to 200 kV RFQ preaccelerator Linac (unique design, "H-wave" type) Ions Energy at exit Length

Parameters
d В
238U32+

5 MeV/amu 25 m

Negotiations at IHEP (Protvino)
21-22 June 2007

August 2007: an agreement achieved October 2007: project development has been started!
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I.Meshkov, NICA Project

Veksler's Century Workshop

Dubna, October 10-12, 2007


8. Booster
"Warm" booster on basement of The Synchrophasotron
B = 25 Tm, Bmax = 1.8 T 1) 5 single-turn injections of 8в109 238U32+ 2) electron cooling 3) bunching 4) Acceleration up to 440 MeV/u 5) Extraction & stripping Nuclotron Booster

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I.Meshkov, NICA Project

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Dubna, October 10-12, 2007


8. Booster (Contnd)

Main Booster parameters Circumference Injection energy U
30+

210 m 5 MeV/u 440 MeV/u 1,8 T 10
-11

Maximum energy U30+ Maximum dipole field Vacuum
I.Meshkov, NICA Project Veksler's Century Workshop

Torr
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Dubna, October 10-12, 2007


8. Booster (Contnd)

Booster layout

KRION + Linac

Booster e-cooler

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I.Meshkov, NICA Project

Veksler's Century Workshop

Dubna, October 10-12, 2007


8. Booster (Contnd)

Booster Location in "The Belly" of The Synchrophasotron

2.3 m 4.3 m

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I.Meshkov, NICA Project

Veksler's Century Workshop

Dubna, October 10-12, 2007


But! Infrastructute

9. Cost Estimate ($M)


~ 17 !

KRION + HV "platform" 0.25 Injector (IHEP design) 10 Booster 8 Collider 2 x 10 Total ~ 40

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I.Meshkov, NICA Project

Veksler's Century Workshop

Dubna, October 10-12, 2007


10. Project Work Organization
Project leaders A.Sissakian, A.Sorin NICA Steering Committee

NICA/MPD Center Theory
A.Sorin, V.Toneev

NICA
A.Kovalenko, I.Meshkov

MPD
V.Kekelidze

Computing
O.Rogachevsky

VBLHE Accelerator division
G.Trubnikov
I.Meshkov, NICA Project Veksler's Century Workshop

VBLHE + LPP
R.Lednitsky/V.Kekelidze
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Dubna, October 10-12, 2007


11. Project Milestones
Stage 1: 2006 - 2008
February 2006 ­ 1st Round Table Physics of the mixed phase October 2006 ­ 2d Round Table Accelerator & Detector concepts

October 31, 2007 ­ CDR November 2007 ­ start of TDR (or EngDR) January 2008 ­ 3d Round Table 2008 ­ TDR completion, beginning of the Booster manufacturing
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Veksler's Century Workshop

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11. Project Milestones (Contnd)

Stage 2: 2008 - 2012 - Design and Construction of NICA (Injector, Booster, Collider) and MPD detector - Infrastructure development Stage 3: 2010 ­ 2012 Facility and Detector assembling Stage 4: 2013

Commissioning, beginning of operation

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I.Meshkov, NICA Project

Veksler's Century Workshop

Dubna, October 10-12, 2007


12. News from RHIC: Low-energy RHIC operation
A.Fedotov, BNL (Talk at COOL'07 September 14, 2007)

RHIC heavy ion collisions at sNN= 5-50 GeV/u

Au beams in RHIC at E

(Workshop at BNL, March 9-10, 2006): "Can one discover the QCD critical point at RHIC?" Suggested energy scan: sNN = 5, 6.3, 7.6, 8.8, 12.3, 18, 28 GeV/u. Two 1-day test runs were done in 2006 and 2007 at low-energies.
33

kin

1.5 В 24.0 GeV/u

I.Meshkov, NICA Project

Veksler's Century Workshop

Dubna, October 10-12, 2007


12. News from RHIC (Contnd)

Test Run at sNN = 9.2 GeV/u (Ekin 3.5 GeV/u)
June 11, 2007 Debunching (decreased IBS) 15 minutes Intensity [Au e9]

T. Satogata et al. PAC07
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I.Meshkov, NICA Project

Veksler's Century Workshop

Dubna, October 10-12, 2007


12. News from RHIC (Contnd)

RHIC Low Energy Program Plans
RHIC low-energy operation is challenging: RF acceptance, IBS, vertex, etc. Tests of low-energy operation were successful: - At sNN=9.2 GeV/n Beam-Beam Collisions rates of 100-700 Hz in STAR has been achieved; - Peak luminosity was about 1.5в10E24 cm-2s-1

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Veksler's Century Workshop

Dubna, October 10-12, 2007


12. News from RHIC (Contnd)

RHIC Program Advisory Committee recommended 14 weeks operation in 2010: - Obtaining minimum requested 5M events per energy point seems feasible. - Obtaining higher statistic > 50M (already requested by some of the experiments) in the future may be produced with electron cooling in RHIC at these energies.

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12. News from RHIC (Contnd)

Developments: - No RHIC upgrades with e-cooler in RHIC is presently planned on this time scale... regardless the fact - Concept of high energy electron cooler is under development at RHIC since ~ 2002. - Application of transverse*) stochastic cooling of bunched beams on experiment energy is considered as a task of first priority.
*)

longitudinal stochastic cooling of bunched beams has been demonstrated at BNL in 2005.
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I.Meshkov, NICA Project

Veksler's Century Workshop

Dubna, October 10-12, 2007


13. NICA again
To cool! Why not? If to cool electron or stochastic cooling? That's a question!

Our choice: stochastic cooling - longitudinal and transverse ones. Challenging, but promising:



IBS

1000 sec!

But ­ R&D is required!

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I.Meshkov, NICA Project

Veksler's Century Workshop

Dubna, October 10-12, 2007


13. NICA again (Contnd)

What further? A fantasy, just a bit ...
Asymmetric (by ion species) collider d x U Electron-ion collider DELSY facility! Ie = 10 mA L ~ 21030 cm-2s-1 !

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I.Meshkov, NICA Project

Veksler's Century Workshop

Dubna, October 10-12, 2007


Conclusion
With NICA project JINR joins community of three labs, which perform (or plan to perform) studies of MP in excited nuclear matter,... ...the project will develop further ...
JINR
L BN

N CER

SI G

...the pioneering ideas outspoken at JINR ...
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I.Meshkov, NICA Project

Veksler's Century Workshop

Dubna, October 10-12, 2007


Conclusion

... and extend our knowledge... ... beyond "the horizon"...

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I.Meshkov, NICA Project

Veksler's Century Workshop

Dubna, October 10-12, 2007


Conclusion

­ - , .

Thank you for your attention
I.Meshkov, NICA Project Veksler's Century Workshop

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Dubna, October 10-12, 2007