Transcript Accelerators COSY and HESR

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Accelerators COSY and HESR
March 15, 2013 | Andreas Lehrach
Outline
Introduction
Cooler Synchrotron COSY
Prototyping and Accelerator Physics
Polarized Beams
Preparation for Storage Ring EDM
High-Energy Storage Ring HESR
Beam Dynamics Simulations
Design Work
Summary/Outlook
March 15, 2013 | A. Lehrach
COSY & HESR
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Cooler Synchrotron COSY
Siberian
Snake
Ions: (pol. & unpol.) p and d
2MV
Electron
Cooler
Momentum:
300/600 to 3700 MeV/c
for p/d, respectively
Circumference of the ring: 184 m
Electron Cooling up to 550 MeV/c
Stochastic Cooling above 1.5 GeV/c
 Major Upgrades
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Prototyping and Accelerator Physics
Pellet Target
Siberian Snake
(2013)
Residual Gas
Profile Monitor
RF Dipole
WASA
Barrier Bucket Cavity
Stochastic Cooling
RF Solenoid
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2 MeV e-Cooler
(2012/13)
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Magnetized High-Energy Electron Cooling:
Development Steps
HESR: 4.5 MeV
Upgradable
to 8 MeV
COSY:
from 0.1 MeV
to 2 MeV
• Technological challenge
• Benchmarking of cooling forces
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Installation at COSY started
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Example: Beam Cooling with WASA Pellet Target
-7
5 10
-7
4 10
-7
3 10
0,25
a) 100Injected beam
0,2
b) 0Beam heated by target
c) -100+ stochastic cooling 0,15
0,1
d)-200+ barrier bucket
d)
-7
2 10
-7
1 10
-7
0
1.5368
0,3
BB Voltage / V
Particle Density (arb. units)
200
c)
-300
0,05
-400
0
-500
-0,05
-600
-0,1
0,0
0,5
1,0
1,5
2,0
Time / µs
b)
a)
1.5369
Phasemonitor a.u.
6 10
1.537
1.5371
1.5372
1.5373
f [GHz]
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Polarized Beams at COSY
Tune-Jump
Qy
Polarization during acceleration
9-Qy
7-Qy
DQy
gG=5
0+Qy
gG=4
gG=6
8-Qy
1+Qy
• Length 0.6 m
• Max. current ±3100 A
• Max gradient 0.45 T/m
• Rise time 10 μs
2+Qy
10-Qy
Intrinsic resonances  tune jumps
Imperfection resonances  vertical orbit excitation
P > 75% at 3.3 GeV/c
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Physics at COSY using longitudinally
polarized beams: Snake Concept
• Should allow for flexible use at two
locations
ANKE
ANKE
• Fast ramping <30s
• Integral long. field >4.7 T m
PAX
• Cryogen-free system?
Bdl (Tm)
COSY Injection Energy 45 MeV
1.103
pn→{pp}sπ- at 353 MeV
3.329
PAX at COSY 140 MeV
1.994
PAX at AD 500 MeV
4.090
Tmax at COSY 2.88 GeV
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13.887
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Siberian Snake at COSY
Superconducting 4.7 Tm solenoid is ordered.
Overall length: 1 m
Ramping time 30 s
Installation at COSY
in summer 2013
Spin dynamics and longitudinal polarized beams for experiments
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Polarization of a Stored Beam by Spin-Filtering
COSY Cycle / schematic
Experiment with COSY / schematic
Spinflipper
Results
COSY Cycle
• Stacking injection at 45 MeV
• Electron cooling on
• Acceleration to 49.3 MeV
• Start of spin-filter cycle at PAX: 16 000 s
• PAX ABS off
• ANKE cluster target on
• Polarization measurement (2 500 s) at ANKE
• Spin flips with RF Solenoid
• New cycle: different direction of target polarization
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Facility for Antiproton and Ion Research
SIS18
SIS100
p-Linac
HESR
70MeV protons, 70mA, ≤4Hz
5·1012 protons/cycle
4·1013 protons/cycle
29GeV protons
bunch compressed to 50nsec
Production target: 2·108 antiprotons/cycle
3% momentum spread
CR:
bunch rotation and stochastic
cooling at 3.8GeV/c, 10s
RESR:
accumulation at 3.8GeV/c
Antiprotonen
Production
Target
Linac:
SIS 18:
SIS 100:
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CR/RESR
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HESR with PANDA and Electron Cooler
COSY
HESR
HESR
COSY
575 m
Circumference
184 m
1.5 – 15 GeV/c
Momentum
0.3 – 3.7 GeV/c
up to 9 GeV/c
Electron Cooling
up to 0.5 GeV/c
Full range
Stochastic Cooling
1.5 – 3.7 GeV/c
Jülich is the leading lab of the HESR Consortium:
Germany (Jülich (90%), GSI, Mainz), Slovenia and Romania
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Criteria for the Layout of the HESR
HESR design driven by the requirements of PANDA:
• Antiprotons with
• High luminosity:
- Thick targets:
1.5 GeV/c ≤ p ≤ 15 GeV/c
2·1032 cm-2s-1
4·1015 cm-2
• High momentum resolution:
- Phase space cooling
Δp/p ≤ 4·10-5
• Long beam life time:
>30 min
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Beam Dynamics Simulations

Beam injection and accumulation: stacking injection concept
(Simulation codes by T. Katayama and H. Stockhorst)

Dynamic aperture calculations and closed-orbit correction: steering and multipole
correction concept
(MAD-X, SIMBAD based on ORBIT)

Beam losses at internal targets / luminosity estimations:
particle losses (hadronic, single Coulomb, energy straggling, single intra-beam)
(Analytic formulas)

Beam-cooling / beam-target interaction / intra-beam scattering: beam equilibria
(BetaCool, MOCAC, PTARGET, Jülich stochastic cooling code)

Ring impedance: RF cavities, kicker etc.
(SIMBAD based on ORBIT)

Trapped ions: discontinuity of vacuum chamber, clearing electrodes
(Analytic codes)
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COSY & HESR
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Injection and Accumulation
Beam accumulation in HESR required
for modularized FAIR start version
• Barrier Bucket and stochastic cooling will be
used to accumulate antiprotons in HESR
• Proof of principle measurement
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COSY & HESR
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Future HESR Upgrade Options
Polarized Proton-Antiprotons Collider
15 GeV/c – 3.5 GeV/c
Spin Filtering
Antiproton Polarizer (APR)
Asymmetric Collider
Polarized Electron-Nucleon Collider ENC
P
tune jump Quads,
partial snake
new
70MeV linac
SIS18
Accelerator Working Group:
full snake
eCool, 8.2MV
HESR
Linac
eSynchrotron
(15GeV/c,
g= 16)
e
spin rotators
around IR
eRing (3.3GeV)
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Summary / Outlook
Prototyping and Accelerator Physics at COSY
Detector tests for PANDA and CBM
Preparation for HESR:
High-Energy Electron Cooling and High-Bandwidth Stochastic Cooling
Internal Targets, RF Manipulation techniques
 COSY is essential to develop and establish these techniques for HESR
Polarized beams at COSY
Polarizing stored Antiprotons by spin-filtering
R&D work for storage ring EDM searches of charged particles
First direct EDM measurement, ideal EDM injector
 COSY is essential to perform R&D work for PAX and EDM
HESR project status
New HESR beam accumulation scheme due to modularized start version of FAIR
Design work of the HESR is finalized and the construction phase started
Main HESR components are ordered (dipoles, quadrupoles, ... )
 corresponds to roughly 30% of total project costs
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COSY & HESR
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Siberian Snake
spin rotation
χ
spin- and particle motion
• Full snake: χ = 180°  νsp = ½
Spin tune independent of beam energy
No spin resonances except snake resonances:
νsp = ½ = k ± l∙Qx ± m∙Qy
• Partial snake: χ < 180°  νsp ≠ k
Keeps the spin tune away from integer
No imperfection resonances
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New 2 MV Electron Cooler at COSY
BINP Novosibirsk
 Energy Range: 0.025 ... 2 MeV
 High-Voltage Stability: < 10-4
 Electron Current: 0.1 ... 3 A
 Electron Beam Diameter: 10 ... 30 mm
 Cooling section length: 2.694 m
 Magnetic field (cooling section): 0.5 ... 2 kG
Installation at COSY started
March 15, 2013 | A. Lehrach
COSY & HESR
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Stochastic Cooling System
•
•
•
•
•
•
•
•
Cooling Bandwidth (2 – 4) GHz
Pickup and Kicker Structures: Circular Slot Type Couplers*)
Aperture 90 mm
Length per cell 12.5 mm
88 pickup cells
Total length: 1100 mm
Zero dispersion at pickup and kicker
Noise temperature pickup plus
equivalent amplifier noise: 40 K
•
•
•
Momentum range 1.5 GeV/c to 15 GeV/c
Above 3.8 GeV/c: Filter Cooling
Below 3.8 GeV/c: TOF Cooling
March 15, 2013 | A. Lehrach
COSY & HESR
R. Stassen, FZJ
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Spin Manipulation in COSY
Jump Quadrupole
Air coil, length 0.6 m
• Current ±3100 A, gradient 0.45 T/m
• Rise time 10 μs, fall time 10 to 40 ms
RF Solenoid
Water-cooled copper coil in a copper box, length 0.6 m
• Frequency range roughly 0.6 to 1.6 MHz
• Integrated field ∫Brms dl ~ 1 T·mm
RF Dipole
8-turn water-cooled copper coil in a ferrite box , length 0.6 m
• Frequency range roughly 0.12 to 1.6 MHz
• Integrated field ∫Brms dl ~ 0.1 T·mm
Siberian Snake (ordered)
Fast-Ramping Superconducting Solenoid, length 0.98m
• Ramp time to maximum 30s
• Integrated field ∫Brms dl = 0.47 Tm
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COSY & HESR
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COSY Upgrade
1. Improved closed-orbit control system for orbit correction in the micrometer range
 Increasing the stability of correction-dipole power supplies
 Increase number of correction dipoles and beam-position monitors (BPMs)
 Improve BPM accuracy, limited by electronic offset and amplifier linearity
 Systematic errors of the orbit measurement (e.g., temperature drift)
2. Alignment of Magnets and BPMs
 More precise alignment of the quadrupole and sextupole magnets
 BPMs have to be aligned with respect to the magnetic axis of these magnets
3. Beam oscillations
 Excited by vibrations of magnetic fields induced by the jitter of power supplies
 Coherent beam oscillation
4. Longitudinal and transverse wake fields
 Ring impedances
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HESR Layout
Main machine parameter
Momentum range
1.5 to 15 GeV/c
Circumference
574 m
Magnetic bending power
50 Tm
Dipole ramp
25 mT/s
Acceleration rate
0.2 (GeV/c)/s
Geometrical acceptances for βt = 2 m
horizontal
4.9 mm mrad
vertical
5.7 mm mrad
Momentum acceptance
± 2.5×10-3
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Dipoles
Number
Magnetic length
Deflection angle
Max B-field
Min B-field
Aperture
44
4.2 m
8.182°
1.7 T
0.17 T
100 mm
Number
Magnetic length
Iron length (arc)
Max gradient
Aperture
84
0.6 m
0.58 m
20 T/m
100 mm
Quadrupoles
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Luminosity Considerations (Full FAIR version)
Antiproton production rate:
2·107 /s
Pellet target:
Transverse beam emittance:
Longitudinal ring acceptance:
Betatron amplitude at PANDA:
Circulating antiprotons:
nt=4·1015 cm-2
1mm·mrad
Δp/p = ±10-3
1m
1011
Relative Loss Rate
Scattering Process
1
( loss
) / s 1
1.5 GeV/c
9 GeV/c
15 GeV/c
Hadronic Interaction
1.8·10-4
1.2·10-4
1.1·10-4
Single Coulomb
2.9·10-4
6.8·10-6
2.4·10-6
Energy Straggling
1.3·10-4
4.1·10-5
2.8·10-5
Touschek (Single IBS)
4.9·10-5
2.3·10-7
4.9·10-8
Total relatve loss rate
6.5·10-4
1.7·10-4
1.4·10-4
1/e Beam lifetime / s
~ 1540
~ 6000
~ 7100
Cycle averaged luminosity
- Momentum 1.5 GeV/c: 0.3 – 0.7 · 1032 cm-2s-1
- Momentum: 15 GeV/c: 1.5 – 1.6 · 1032 cm-2s-1
March 15, 2013 | A. Lehrach
COSY & HESR
(Production rate: 1 – 2 · 107 /s)
A. Lehrach et al., NIMA 561 (2006)
O. Boine-Frankenheim et al., 560 (2006)
F. Hinterberger, Jül-4206 (2006)
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Cooled Beam Equilibria
Beam cooling, beam-target interactions, intra-beam scattering
rms relative momentum spread p/p
Electron cooled beams
 HR mode: 7.9·10-6 (1.5 GeV/c) to 2.7·10-5 (8.9 GeV/c), and 1·10-4 (15 GeV/c)
 HL mode: <10-4
D. Reistad et al:, Proc. of the Workshop on Beam Cooling
and Related Topics COOL2007, MOA2C05, 44 (2007)
O. Boine-Frankenheim et al., A 560 (2006) 245–255
Stochastic cooled beams
 HR mode: 5.1·10-5 (3.8 GeV/c), 5.4·10-5 (8.9 GeV/c), and 3.9·10-5 (15 GeV/c)
 HL mode: ~10-4
Transverse stochastic cooling can be adjusted independently
H. Stockhorst et al., Proc. of the European Accelerator
Conference EPAC2008, THPP055, 3491 (2008).
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pressure / mbar
Expected Pressure Distribution
and Neutralization Factor
PANDA IP
1,0E-05
The mean time for residual gas
ions in the antiproton beam Tc
(clearing time) in relation to the
time of ion production Tp:
1,0E-06
1,0E-07
1,0E-08
1,0E-09
1,0E-10
0
100
200
300
400
500
600
neutralization factor
s/ m
Tc

Tp
Average distance of clearing
electrodes of 10 m,
with a clearing voltage of 200 V
1,0E+00
1,0E-01
 Emittance Growth
 Incoherent Tune Shift
 Beam Instabilities
1,0E-02
1,0E-03
1,0E-04
0
100
200
300
400
500
600
s/ m
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Coherent Beam Instabilities
Resonance frequencies: (8 − Qx) = 0.4005 and (8 − Qy) = 0.3784,
(9 − Qx) = 1.4005 and (9 − Qy) = 1.3784
Bounce frequencies of transverse H+2 ion oscillations represented as tune numbers qx,y
horizontal
vertical
Beam momentum
p = 15 GeV/c
Estimates for beam instabilities
F. Hinterberger, Ion Trapping in the High-Energy Storage Ring HESR, JÜL-Report 4343 (2011)
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Dynamic Aperture (Optimized)
Orbit diffusion coefficient D
Dynamic Aperture
16 mm mrad
Orbit diffusion coefficient (e.g. after 1000 and 2000 turns):

( 2)
(1) 2
( 2)
(1) 2 
D  log10  Qx  Qx   Qy  Qy  


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