Oleksiy Dolinskyy May 22, 2013 Outline Tasks of the CR - - PowerPoint PPT Presentation

Oleksiy Dolinskyy May 22, 2013

• Tasks of the CR
• Requirements to the ring
• Optics solutions
• Corrections
• Injection / extraction
• Overview

Outline

FAIR layout

Collector Ring

Magnetic rigidity 13 Tm Circumference 221.45 m Structure of a period FODO Number of periods 20 Number of superperiods 2 Number of dipoles 24

• f quadrupoles

40

• f sextupoles

24

• f inj.kickers

3

• f extr.kickers

1

• f RF cavities 5 (10)
• f S.C. tanks 5 (2)

The main task of the CR

Fast pre-cooling of the hot ion beams coming from separators at the maximum magnetic rigidity of BR=13 Tm.

Produced beams on the targets have the large momentum spread and transverse emittance. The CR needs large aperture magnet to collect the maximum possible beam intensity.

Beams from separators

29 GeV protons from SIS100 target station 3 GeV antiprotons

CR 740 MeV/u RIBs 740 MeV/u RIBs 740 MeV/u RIBs 740 MeV/u RIBs

Production yield of antiprotons

• 150
• 100
• 50

50 100 150

• 50
• 40
• 30
• 20
• 10

10 20 30 40 50 x [mm] x' [mrad]

after target after horn acceptance of separator

p = 3.82 GeV/c ∆p/p = ± 3%

yield = pbars in the ellipse primary protons

Simulations give a yield of 2 × 10-5 pbar/p (only target/horn): For 1013 proton one gets 2x108 pbars 11 cm Ni target (d = 3 mm) in a graphite container, 0.62 mm (rms) beam spot. A dramatic improvement of this yield is not possible (without increasing the momentum acceptance of separator/CR).

E(p), E(pbar) 29 GeV, 3 GeV acceptance 240 mm mrad, 6% protons / pulse ≥ 2 × 1013 pulse length single bunch (50 ns) cycle time 10 s

240 mm mrad Less then 7 % of produced particles on the target can be accepted by the pbar separator and the CR

Tasks of the CR

.

1.5 sec

ε ⊥ ≤ 0.5 mm mrad ∆p/p ≤ 0.05 %

CR

.

ε ⊥ ≤ 5 mm mrad ∆p/p ≤ 0.1 %

10 sec

CR

.

CR

few turns f f m m

tr

∆ = ∆

2

γ From Super-FRS to the RESR From antiproton separator to the HESR From Super-FRS

Cooling of antiproton beams

ε ⊥ = 240 mm mrad ∆p/p = 6 %

Cooling of secondary beams of radioactive ions

ε ⊥ = 200 mm mrad ∆p/p = 3 %

Mass spectrometer of radioactive ions (TOF)

ε ⊥ = 100 mm mrad ∆p/p = 1 %

First step of cooling- RF bunch rotation

Using bunch rotation RF cavity the momentum spread is reduced by factor of 3 Using bunch rotation RF cavity the momentum spread is reduced by factor of 3 Using bunch rotation RF cavity the momentum spread is reduced by factor of 3 Using bunch rotation RF cavity the momentum spread is reduced by factor of 3 P P P P-

• bars (from 6% to less than 2%)

bars (from 6% to less than 2%) bars (from 6% to less than 2%) bars (from 6% to less than 2%) RIBs (from 3% to less then 1 %) RIBs (from 3% to less then 1 %) RIBs (from 3% to less then 1 %) RIBs (from 3% to less then 1 %) Time of such cooling is about 3 Time of such cooling is about 3 Time of such cooling is about 3 Time of such cooling is about 3 ms ms ms ms

p/p=6%

p/p=2%

Second step of cooling- Stochastic cooling

X‘ X X‘ X

ε ε ε εh,V =240

=240 =240 =240 mm mrad

ε ε ε εh,V

≤ ≤ ≤ ≤ 5 5 5 5 mm mrad ∆ ∆ ∆ ∆p/p < ± ± ± ± 0.05% Stochastic cooling

After bunch rotation Stochastic cooling is applied to reduce both the beam emittance and momentum spread

Pbar Pbar Pbar Pbar : Momentum spread : Momentum spread : Momentum spread : Momentum spread -

• from 2% to 0.1%

from 2% to 0.1% from 2% to 0.1% from 2% to 0.1% Emittance Emittance Emittance Emittance -

• from 240 to 5 mm

from 240 to 5 mm from 240 to 5 mm from 240 to 5 mm mrad mrad mrad mrad

Cooling time Cooling time Cooling time Cooling time -

• 10

10 10 10 seconds seconds seconds seconds RIBs: RIBs: RIBs: RIBs: RIB momentum spread from 1 % to 0.05 %

RIB momentum spread from 1 % to 0.05 % RIB momentum spread from 1 % to 0.05 % RIB momentum spread from 1 % to 0.05 % Emittance Emittance Emittance Emittance from 200 to 0.5 mm from 200 to 0.5 mm from 200 to 0.5 mm from 200 to 0.5 mm mrad mrad mrad mrad (time 1.5 seconds)

(time 1.5 seconds) (time 1.5 seconds) (time 1.5 seconds) Cooling time Cooling time Cooling time Cooling time – – – – 1.5 sec 1.5 sec 1.5 sec 1.5 sec

Requirements to the ring

• Three optics must be prepared
• Efficient Stochastic Cooling for two optics
• High power RF systems for Debuncher
• Large acceptances for all 3 optics
• Injection / extraction should guarantee

large ring acceptance

Stochastic cooling requires:

• High frequency RF system for signal

High frequency RF system for signal High frequency RF system for signal High frequency RF system for signal processing processing processing processing

• High impedance and sensitivity electrodes

High impedance and sensitivity electrodes High impedance and sensitivity electrodes High impedance and sensitivity electrodes for Pick for Pick for Pick for Pick-

• Up system

Up system Up system Up system

• Dispersion free drift spaces (10

Dispersion free drift spaces (10 Dispersion free drift spaces (10 Dispersion free drift spaces (10-

• 14 m)

14 m) 14 m) 14 m)

• Mixing conditions must be close to the

Mixing conditions must be close to the Mixing conditions must be close to the Mixing conditions must be close to the ideal (this depends on the ring optics) ideal (this depends on the ring optics) ideal (this depends on the ring optics) ideal (this depends on the ring optics)

Stochastic cooling: Mixing (M)

MPK≈ ∞ MKP ≈ 1

( )

p p n n M / 1

1 2

δ η − =

2 2

1 1

tr

γ γ η − =

Energy Energy Energy Energy (for pbar (for pbar (for pbar (for pbar γ γ γ γ=4.2 (3000 GeV) =4.2 (3000 GeV) =4.2 (3000 GeV) =4.2 (3000 GeV) For RIB For RIB For RIB For RIB γ γ γ γ=1.86 (740 MeV/u =1.86 (740 MeV/u =1.86 (740 MeV/u =1.86 (740 MeV/u ) ) ) ) Ring parameter depends on Ring parameter depends on Ring parameter depends on Ring parameter depends on the ring optics the ring optics the ring optics the ring optics These are ideal conditions These are ideal conditions These are ideal conditions These are ideal conditions for mixing for mixing for mixing for mixing

Isochronous mode (gamma6 tr=1.8) Rib mode (gamma6tr=2.9) Pbar mode (gamma6tr=3.8)

Dx (m)

0 10 20 25

path length s (m)

106

8 . 1 =

tr

γ 9 . 2 =

tr

γ 8 . 3 =

tr

γ

dispersion function over a half of the ring

Requirements to the ring optics

pick-up kicker

∫

∆

∆ =

L KP PK tr

ds s s D L

, 2

) ( ) ( 1 1 ρ γ

ΔL – path length ρ – bending radius of dipole

The arcs are optimased to have a flexible dispersion variation in arcs (D(arc). At least 4 families of quadrupole magnets are required. (D(arc), D‘(arc), D(drift)=D‘(drift)=0)

( )

1 2 2 + = ∆ n

PK

π θ

The quantum number of a phase between Pick-Up and Kicker is

• required. Phase advance must be

900 or plus a multiple of 1800.

n=0,1,2…

Stochastic Cooling requires:

i

It must be performed both for p-bar and RIB optics

Phase advance control between PU and KU

Stochastic cooling in the CR

Bad mixing Good mixing

The The The The CR CR CR CR is is is is designed designed designed designed to to to to have have have have required required required required η η η η parameter parameter parameter parameter both both both both for for for for antiproton antiproton antiproton antiproton and and and and RIB RIB RIB RIB beams beams beams beams. . . . Optic Optic Optic Optic and and and and positions positions positions positions of

• f
• f
• f PU

PU PU PU and and and and KI KI KI KI are are are are optimised

• ptimised
• ptimised
• ptimised to

to to to have have have have required required required required phase phase phase phase advances advances advances advances between between between between all all all all pairs pairs pairs pairs of

• f
• f
• f PU

PU PU PU-

• KI

KI KI KI. . . .

Pick-Up (1-2 GHz)

Palmer cooling PU

2 Pickup tanks (1-2 GHz) 2 Kicker tanks (1-2 GHz) 1 Palmer Pickup tanks 1 – Pickup tank (2-4 GHz) 1 – Kicker tank (2-4 GHz)

Optics solutions

Optics solutions

!" # $ #% % #& '(")*+ ',-.+ /(!*+ 010/,2+ (2,/(10+ *0",3

• 42,'*+ !*-",!) /5(

# 6% + 7 88+ %+ % # 883 # 8 !" # 6 9*-* ## 8:6 +

• +

6

• %

%+ !*-+ % % %#% #3

antiproton optics

dispersion function D(s)

betatron functions βx βy

The average dispersion is about 4 m

The γtr=3.85 (η=-0.011) Qh=4.27; Qv=4.84 4 Quadrupole families are required to control βx,y and x,y 4 Quadrupole families are needed for dispersion control 3 Quadrupole families are needed for matching to the straight section

Total 11 Quadrupole famileis are needed for the CR

antiproton optics

Antiproton beam: εx=240 mm mrad εy=240 mm mrad ∆p/p=±3.0 % γtr=3.85 η=60.011 The effective horizontal aperture of quadrupoles in the arcs is 400 mm. In the vertical plane is 140- 180 mm. p p s D s A ∆ + = ) ( 2 ) ( 2 εβ

The required aperture of the CR magnets

Radioactive Ion Beam mode

path length, s [m]

21 Y [cm] X 10 106

p p s D s A ∆ + = ) ( ) ( 2 εβ

dispersion function D(s) betatron functions βx βy

εx,y=200 mm mrad p/p=±1.5 %

• Hor. Aperture up to A=40 cm
• Ver. Aperture= 14-180 cm

Horizontal and vertical beam envelopes over a half of the ring.

Isochronous Mode of the CR

• 1. γt = γ = 1.84 (E = 782.5 MeV/u)
• 2. γt = γ = 1.67 (E = 624.1 MeV/u)
• 3. γt = γ = 1.43 (E = 400.5 MeV/u)

TOF mass measurements

error tr tr

f f v v q m q m f f         + ∆         − + ∆ − = ∆ δ γ γ γ

2 2 2

1 / ) / ( 1 Isochronous mode ( Isochronous mode ( Isochronous mode ( Isochronous mode ( γ γ γ γtr

tr tr tr = γ ) is required

= γ ) is required = γ ) is required = γ ) is required for fast for fast for fast for fast mass measurements. mass measurements. mass measurements. mass measurements.

Isochronous mode

Optic parameters in the isochronous mode

Isochronous Mode of the CR

The The The The CR CR CR CR dipole dipole dipole dipole field field field field homogeneity homogeneity homogeneity homogeneity is is is is crucial crucial crucial crucial for for for for the the the the time time time time resolution resolution resolution resolution. . . . The The The The decapole decapole decapole decapole component component component component of

• f
• f
• f

the the the the dipole dipole dipole dipole magnet magnet magnet magnet field field field field affects affects affects affects strongly strongly strongly strongly the the the the time time time time resolution resolution resolution resolution. . . . The The The The decapole decapole decapole decapole correction correction correction correction is is is is required required required required. . . . In In In In present present present present design design design design of

• f
• f
• f the

the the the CR CR CR CR this this this this correction correction correction correction is is is is not not not not foreseen foreseen foreseen foreseen. . . . This This This This option

• ption
• ption
• ption is

is is is under under under under discussion discussion discussion discussion. . . .

• S. Litvinov, A. Dolinskii et. al., “Isochronicity Correction in the CR Storage Ring“, NIMA, 2013.

Isochronous mode

Required nonlinear correction

Corrections

nonlinear correction

24 sextupole magnets (6 families) are needed for : * Chromaticity correction * Control of the dispersion function * Avoiding synchrobetatron coupling 8 octupole correctors (2 families ) for minimizing of the fringe field effect of quadrupoles in the isochronous mode operation

24 sextupole magnets (6 families)

∆Qh,v≈ 0.02 in Pbar mode Qh,v ≈ 0.02 in RIB mode

after correction

without correction

Required sextupole magnet

• Total required number 24

Total required number 24 Total required number 24 Total required number 24

• Sextupole 12

Sextupole 12 Sextupole 12 Sextupole 12

• Sextupole with vertical correction 12

Sextupole with vertical correction 12 Sextupole with vertical correction 12 Sextupole with vertical correction 12

• Max. field gradient, [T/m**2] 10
• Max. field gradient, [T/m**2] 10
• Max. field gradient, [T/m**2] 10
• Max. field gradient, [T/m**2] 10
• Effective length, [m] 0.6

Effective length, [m] 0.6 Effective length, [m] 0.6 Effective length, [m] 0.6

• Hor./Vert. good field area, [mm] 400/180

Hor./Vert. good field area, [mm] 400/180 Hor./Vert. good field area, [mm] 400/180 Hor./Vert. good field area, [mm] 400/180

• Field quality,

Field quality, Field quality, Field quality, δ δ δ δB/B, B/B, B/B, B/B, ± ± ± ±5x10 5x10 5x10 5x10-

• 3

3 3 3

Required parameters

Closed Orbit Correction

• ptics

Type of correctors COD rms/max Kick angle rms/max Before cor After cor mm mm mrad H(pbar) 12(dip)+6(h/v) 7.8 / 18 0.9 / 4.1 0.7 /2.4 V(pbar) 12(sex)+6(h/v) 4.1 /11.2 1.3 / 3.3 1.2 / 4.7 H (RIB) 12(dip)+6(h/v) 6.2/15.2 1.1/2.61 0.61/2.5 V (RIB) 12(sex)+6(h/v) 3.6/9.2 0.61/1.9 0.74/2.81

The The The The CODTRACK CODTRACK CODTRACK CODTRACK code code code code was was was was developed developed developed developed to to to to calculate calculate calculate calculate and and and and correct correct correct correct the the the the closed closed closed closed

• rbit
• rbit
• rbit
• rbit

distortion distortion distortion distortion in in in in the the the the ring ring ring ring. . . . The The The The statistical statistical statistical statistical simulations simulations simulations simulations were were were were performed performed performed performed to to to to define define define define the the the the required required required required kick kick kick kick strength strength strength strength of

• f
• f
• f the

the the the corrector corrector corrector corrector magnet magnet magnet magnet. . . . CODs calculated by the CODTRACK

Analyses of 2x10 Analyses of 2x10 Analyses of 2x10 Analyses of 2x104

4 4 4 seeds for 18 corrector magnets

seeds for 18 corrector magnets seeds for 18 corrector magnets seeds for 18 corrector magnets Distribution of kick strength Distribution of kick strength Distribution of kick strength Distribution of kick strength

Closed Orbit Correction

18 BPM 18 BPM 18 BPM 18 BPM – – – – beam position monitor are beam position monitor are beam position monitor are beam position monitor are embedded in the quadrupole magnets embedded in the quadrupole magnets embedded in the quadrupole magnets embedded in the quadrupole magnets Precision of measurement is 0.8 mm Precision of measurement is 0.8 mm Precision of measurement is 0.8 mm Precision of measurement is 0.8 mm 18 vertical and horizontal correctors 18 vertical and horizontal correctors 18 vertical and horizontal correctors 18 vertical and horizontal correctors 12 12 12 12 – – – – hor. corr. in dipole magnets

• hor. corr. in dipole magnets
• hor. corr. in dipole magnets
• hor. corr. in dipole magnets

12 12 12 12 – – – – vert. corr. in sextupole magnets

• vert. corr. in sextupole magnets
• vert. corr. in sextupole magnets
• vert. corr. in sextupole magnets

6 6 6 6 – – – – h/v corr. separated magnets h/v corr. separated magnets h/v corr. separated magnets h/v corr. separated magnets

BPM-1 BPM-2 BPM-3 BPM-4 BPM-5 BPM-6 BPM-7 BPM-8 BPM-9 BPM-10 BPM-11 BPM-12 BPM-13 BPM-16 BPM-17 BPM-15 BPM-14 BPM-18

The The The The Vertical Vertical Vertical Vertical corrector corrector corrector corrector coil coil coil coil is is is is embedded embedded embedded embedded in in in in the the the the sextupole sextupole sextupole sextupole. . . . The The The The technical technical technical technical design design design design is is is is under under under under development development development development. . . . 3 3 3 3 mrad mrad mrad mrad kick kick kick kick strength strength strength strength is is is is required required required required. . . . The The The The BPM BPM BPM BPM is is is is embedded embedded embedded embedded in in in in the the the the wide wide wide wide aperture aperture aperture aperture quadruople quadruople quadruople quadruople magnet magnet magnet magnet

BPM and Vertical corrector in magnets

Wide Quadrupole with BPM

18 18 18 18 BPM BPM BPM BPM must must must must be be be be embedded embedded embedded embedded in in in in the the the the wide wide wide wide quadupole quadupole quadupole quadupole magnets magnets magnets magnets. . . . The The The The vacuum vacuum vacuum vacuum chamber chamber chamber chamber has has has has a a a a star star star star shape shape shape shape. . . . It It It It is is is is proposed proposed proposed proposed to to to to include include include include the the the the vacuum vacuum vacuum vacuum chambers chambers chambers chambers with with with with BPM BPM BPM BPM as as as as a a a a part part part part of

• f
• f
• f the

the the the CR CR CR CR diagnostic diagnostic diagnostic diagnostic system system system system. . . .

BPM BPM + Vacuum chamber

sextupole magnet with correctors

sextupole magnet sextupole magnet sextupole magnet sextupole magnet sextupole magnet with corrector coil sextupole magnet with corrector coil sextupole magnet with corrector coil sextupole magnet with corrector coil A A A A new new new new design design design design of

• f
• f
• f the

the the the sextupole sextupole sextupole sextupole magnet magnet magnet magnet with with with with dipole dipole dipole dipole coils coils coils coils is is is is performed performed performed performed in in in in the the the the collaboration collaboration collaboration collaboration work work work work with with with with the the the the Budker Budker Budker Budker Institute Institute Institute Institute (Novosibirsk) (Novosibirsk) (Novosibirsk) (Novosibirsk). . . . The The The The Vacuum Vacuum Vacuum Vacuum chamber chamber chamber chamber is is is is developed developed developed developed as as as as well well well well. . . . It It It It is is is is proposed proposed proposed proposed to to to to reduce reduce reduce reduce the the the the yoke yoke yoke yoke length length length length from from from from 0. . . .6 6 6 6 m m m m to to to to 0 0. . . .5 5 5 5 m m m m. . . . dipole coil dipole coil dipole coil dipole coil

Dynamic aperture

Field quality dipole magnet dB/B =±1*1064 quadrupole magnet dQ/Q=±5*1064 Particle tracking: 1000 turns

Dynamic aperture with field imperfection up 9th order Fringe field effect of quadrupole magnets is included

Particle tracking simulations

Particle distribution after injection in the CR Q01 quadrupole (matching point)

1000 turns in the CR

Particle tracking with momentum collimation including chromatic effect and nonlinear field imperfection of all magnets

• f

the separator.

The particle distribution after horn lens (MARS calculation) From p6bar target

CR

RESR

separator acceptance CR acceptance (dp/p=0)

Calculated beam losses with particle tracking codes.

8 % of particles loss due to nonlinear mismatching of the p-bar separator to the CR. 7% of particles loss due to all nonlinear effects of the CR machine (fringe field, chromatic effects, amplitude dependence, high order field imperfection and other.

Dynamic aperture

7 % 8 %

15 % of beam loss

Requirements to the dipole magnet

2D, 3D simulations have been done with the OPERA code. Present design is optimized for the maximum field of 1.6 T to have required field quality. The technical design is finished. The final specification is under way in a collaboration work with Budker Institute (Novosibirsk)

1 x 1064 61 x 1064

• Required number 24

Required number 24 Required number 24 Required number 24

• Max. magnetic field [T] 1.6
• Max. magnetic field [T] 1.6
• Max. magnetic field [T] 1.6
• Max. magnetic field [T] 1.6
• Bending angle [Grad] 15

Bending angle [Grad] 15 Bending angle [Grad] 15 Bending angle [Grad] 150

• Bending radius [m] 8.125

Bending radius [m] 8.125 Bending radius [m] 8.125 Bending radius [m] 8.125

• Effective length 2.2

Effective length 2.2 Effective length 2.2 Effective length 2.2

• Hor.Vert. good field area 380 /140 mm

Hor.Vert. good field area 380 /140 mm Hor.Vert. good field area 380 /140 mm Hor.Vert. good field area 380 /140 mm2

2 2 2

• Field quality ,

Field quality , Field quality , Field quality , δ δ δ δB/B B/B B/B B/B 2 x 10 2 x 10 2 x 10 2 x 10-

• 4

4 4 4

Injection / extraction

Injection / extraction

(TDR 2007)

Injection / extraction (TDR 2007)

3 kicker magnets (6 modules) were planned only for injection 3 kicker magnets (6 modules) were planned only for injection 3 kicker magnets (6 modules) were planned only for injection 3 kicker magnets (6 modules) were planned only for injection (wide aperture) (wide aperture) (wide aperture) (wide aperture) 1 kicker magnet (5 modules) was planned only for extraction 1 kicker magnet (5 modules) was planned only for extraction 1 kicker magnet (5 modules) was planned only for extraction 1 kicker magnet (5 modules) was planned only for extraction (narrow aperture) (narrow aperture) (narrow aperture) (narrow aperture)

Injection / extraction (present layout)

Injection into the ring (present layout)

injection septum kicker magnet quadrupole Q04 Q03 Q02 Q01 Q02

4 kicker magnets (12 modules) are needed both for injection and

• extraction. All modules are identical.

The The The The design design design design of

• f
• f
• f the

the the the CR CR CR CR inj/extr inj/extr inj/extr inj/extr kickers kickers kickers kickers is is is is similar similar similar similar to to to to the the the the existing existing existing existing unipolar unipolar unipolar unipolar kicker kicker kicker kicker system system system system. . . . The The The The polarity polarity polarity polarity change change change change is is is is required required required required 2 kickers for extraction

Ion-optics of injection

Total kick angle of 15 mrad is required. 2 Full aperture kickers are placed not on the optical axes of the CR.

extraction of p-bars

Extraction acceptance Ex=20 mm mrad

(expected emittance of cooled beam is less then 5 mm mrad)

Septum magnet 6 modules

20 mm mrad

Extraction of RIBs

Septum magnet 6 modules

20 mm mrad Extraction acceptance Ex=20 mm mrad

(expected emittance of cooled beam is less then 1 mm mrad)

kicker magnet requirements

Rigidity min / max Rigidity min / max Rigidity min / max Rigidity min / max 13 Tm 13 Tm 13 Tm 13 Tm Total deflection (kick) angle Total deflection (kick) angle Total deflection (kick) angle Total deflection (kick) angle ± ± ± ± 14 mrad 14 mrad 14 mrad 14 mrad Number of modules Number of modules Number of modules Number of modules 12 12 12 12 Full aperture 400 x 150 mm Full aperture 400 x 150 mm Full aperture 400 x 150 mm Full aperture 400 x 150 mm Overall length Overall length Overall length Overall length 8 m 8 m 8 m 8 m Rise rise/fall time 300 ns Rise rise/fall time 300 ns Rise rise/fall time 300 ns Rise rise/fall time 300 ns Flat top length 120 ns Flat top length 120 ns Flat top length 120 ns Flat top length 120 ns

kicker magnet

1 kicker magnet with 3 modules

Magnet field along the 3 kicker modules Particle tracking through the all 4 kickers in the CR Phase space of particle after tracking

Basic CR parameters

Circumference Circumference Circumference Circumference m m m m 221.45 221.45 221.45 221.45

• Max. magnetic rigidity
• Max. magnetic rigidity
• Max. magnetic rigidity
• Max. magnetic rigidity

Tm Tm Tm Tm 13 13 13 13 Anti Anti Anti Anti-

• protons

protons protons protons Rare isotopes Rare isotopes Rare isotopes Rare isotopes Isochronous mode Isochronous mode Isochronous mode Isochronous mode

• Max. number of particles
• Max. number of particles
• Max. number of particles
• Max. number of particles

10 10 10 108

8 8 8

10 10 10 109

9 9 9

1 1 1 1-

• 10

10 10 108

8 8 8

Kinetic energy Kinetic energy Kinetic energy Kinetic energy MeV/n MeV/n MeV/n MeV/n 3000 3000 3000 3000 740 740 740 740 790 790 790 790 Velocity, β Velocity, β Velocity, β Velocity, β v/c v/c v/c v/c 0.971 0.971 0.971 0.971 0.83 0.83 0.83 0.83 0.84 0.84 0.84 0.84 Lorentz, γ Lorentz, γ Lorentz, γ Lorentz, γ 4.2 4.2 4.2 4.2 1.79 1.79 1.79 1.79 1.84 1.84 1.84 1.84 Transition energy, γ Transition energy, γ Transition energy, γ Transition energy, γtr

tr tr tr

3.85 3.85 3.85 3.85 2.82 2.82 2.82 2.82 1.67 1.67 1.67 1.67-

• 1.84

1.84 1.84 1.84 Frequency slip factor , η Frequency slip factor , η Frequency slip factor , η Frequency slip factor , η

• 0.011

0.011 0.011 0.011 0.178 0.178 0.178 0.178 Betatron tunes , Q Betatron tunes , Q Betatron tunes , Q Betatron tunes , Qh

h h h / Q

/ Q / Q / Qv

v v v

4.27 / 4.84 4.27 / 4.84 4.27 / 4.84 4.27 / 4.84 3.17 / 3.67 3.17 / 3.67 3.17 / 3.67 3.17 / 3.67 2.23 / 4.64 2.23 / 4.64 2.23 / 4.64 2.23 / 4.64 Revolution frequency Revolution frequency Revolution frequency Revolution frequency MHz MHz MHz MHz 1.315 1.315 1.315 1.315 1.124 1.124 1.124 1.124 1.137 1.137 1.137 1.137 Bunch length at injection Bunch length at injection Bunch length at injection Bunch length at injection ns ns ns ns 50 50 50 50 50 50 50 50 50 50 50 50 Bunch length at extraction Bunch length at extraction Bunch length at extraction Bunch length at extraction ns ns ns ns 300 300 300 300-

• 500

500 500 500 200 200 200 200-

• 700

700 700 700 no extraction no extraction no extraction no extraction Beam injection Beam injection Beam injection Beam injection fast single turn, full aperture fast single turn, full aperture fast single turn, full aperture fast single turn, full aperture Beam extraction Beam extraction Beam extraction Beam extraction fast single turn fast single turn fast single turn fast single turn no extraction no extraction no extraction no extraction Average vacuum Average vacuum Average vacuum Average vacuum mbar mbar mbar mbar 10 10 10 10-

• 9

9 9 9

• The CR is a special ring that is designed only for fast cooling of RIB and

antiprotons (which have different injection energy 740 MeV/u and 3 GeV).

• Stochastic cooling is an essential task of the CR
• The optical layout of the ring is chosen such to meet the requirements for

most efficient stochastic cooling

• The flexibility in setting the transition energy γtr to an optimal value is

extremely important. (One needs: Good mixing KI6PU, Bad mixing PU6KI). This is necessary to reach as fast as possible cooling time for two optics.

• The phase advance between PU6KU must be quantum number (proportional

900).

• Furthermore: the injection/extraction elements, RF cavities must be placed

also at appropriate locations (Phase advance between kicker and septum magnet must be close to 900 )

• One should remember that one needs to install enough diagnostic

instruments in order to measure the beam parameters with specific features: extremely large beam size , low intensity up to 103 particles).

Overview