nufact'06 wg3, aug. 2006a. fabich, cernbeta-beam ion losses, 1 the eurisol beta-beam...
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NuFact'06 WG3, Aug. 2006
A. Fabich, CERN Beta-beam Ion Losses, 1
The EURISOL Beta-beam Acceleration Scenario:
Ion Losses
A. Fabich, CERN
NuFact’06, UCIrvine
NuFact'06 WG3, Aug. 2006
A. Fabich, CERN Beta-beam Ion Losses, 2
Outline
EURISOLDS Beta-beam layout Accumulation & accelerator cycle Ion intensities
Accelerator chain Decay distribution Dynamic vacuum
Decay ring Stored energy Particle turnover
NuFact'06 WG3, Aug. 2006
A. Fabich, CERN Beta-beam Ion Losses, 3
Beta-beam EURISOL design
Neutrino
Source
Decay Ring
Ion production
ISOL target & Ion source
Proton Driver
SPS
Acceleration to medium
energy RCS
PS
Acceleration to final energy
PS & SPS
Beam to experiment
Ion acceleration
Linac
Beam preparation ECR
pulsed
Ion production Acceleration Neutrino source
Low-energy part
High-energy part
Decay ringBmax = 1000 TmB = ~6 TC = ~7000 m Lss= ~2500 m 6He: = 100 18Ne: = 100
NuFact'06 WG3, Aug. 2006
A. Fabich, CERN Beta-beam Ion Losses, 4
mag
net
cyc
le (
abs
tra
ct)
cycle of 6He
Machine cycle
Baseline version:
Production 6He, 18Ne
ECR, Linac and RCS Cycling at 10 Hertz
Accumulation in the PS Accumulation of 20 RCS bunches (~2 seconds)
Acceleration through PS and SPS as fast as possible top = 100 for both isotopes
Injection into decay ring Merging with circulating bunches Every 6 s for 6He and every 3.6 s for 18Ne
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A. Fabich, CERN Beta-beam Ion Losses, 5
For the design goal of2.9*1018 antineutrinos/year1.1*1018 neutrinos/year
Required isotope intensities: For cycling of version EURISOL DS
Typical intensities of 108-109 ions for LHC injector operation (PS and SPS)
Ion intensities (1)
6He 18Ne
Decay ring [ions stored] 9.7*1013 7.5*1013
SPS ej [ions/cycle] 9. 0*1012 4.3*1012
PS ej [ions/cycle] 9.5*1012 4.3*1012
Source rate to ECR [ions/s] 2*1013 2*1013
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A. Fabich, CERN Beta-beam Ion Losses, 6
Ion intensities (2)
Cycle optimized for neutrino rate.
30% of first 6He bunch injected are reaching decay ring Overall only 50% (6He) and 80% (18Ne) reach decay ring
Normalization Single bunch intensity to maximum/bunch Total intensity to total number accumulated in RCS
Bunch20th
15th
10th
5th1st
total
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A. Fabich, CERN Beta-beam Ion Losses, 7
Decay losses
Relative decay distribution similar for both isotopes
~90% of all decays before entering decay ring occur in the PS
Can be translated into power losses and compared with “existing” high intensity
operation …
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A. Fabich, CERN Beta-beam Ion Losses, 8
pressure evolution in the PS V7
1E-10
1E-09
1E-08
1E-07
0 0.5 1 1.5 2 2.5 3 3.5
t / s
av
era
ge
pre
ss
ure
/ P
a
He
Ne
1E-9
Loss distribution and dyn. vacuumloss distribution in the PS
1E+03
1E+04
1E+05
0 5 10 15 20 25 30
S / m
be
am
lo
ss
es
/ a
.u.
HeNe
loss distribution in the SPS (1 normal cell)
1E+02
1E+03
1E+04
1E+05
1E+06
0 10 20 30 40 50 60
S / m
Lo
ss
es
/ a
.u.
He2+
Ne10+
loss distribution in the PS V7
1E+02
1E+03
1E+04
1E+05
0 10 20 30 40 50
S / m
be
am
lo
ss
es
/ a
.u.
He
Ne
pressure evolution in the SPS
1E-07
1E-06
0.0 1.0 2.0 3.0 4.0 5.0
t / sav
erag
e p
ress
ure
/ P
a
HeNeHe G7Ne G7
PS
SPS
New“PS”
Pressure evolution due to desorption
P. Spiller et al., GSI
Ave
rage
pre
ssur
e [m
bar]
1E-10
1E-11
1E-12
1E-8
Ave
rage
pre
ssur
e [m
bar]
1E-9
PS
SPS
New“PS”
NuFact'06 WG3, Aug. 2006
A. Fabich, CERN Beta-beam Ion Losses, 9
Beam intensities in the decay ring
Stored energy LHC refers to proton operation.
Transverse density: =Estored/(2*Pi*x*y)
Beta-beam operates at reasonable stored energy and energy density. “Stored energy” is most relevant for irregular operation.
LHC project report 773
bb
bb
NuFact'06 WG3, Aug. 2006
A. Fabich, CERNBeta-beam Ion Losses,
10
Particle turnover 810 kJ respect. 1150 kJ beam energy/cycle injected ejected
All ions have to be removed again Either as parent or daughter ion
1) Decay deposition in arcs: protect SC dipoles from quench caused by deposition accumulated after drift (quench limit 10W/m)
2) Decays accumulated along straight section: 300 or 400 kJ dumped per cycle (50 or 120 kW average) via extraction system at end of straight section
3) Momentum collimation at/after merging process: Cycle average: 62 or 230 kW (6 resp 3.6 s)
LHC: 10 kW average, peak 100 kW over seconds or 500 kW peak Process average: 1.2 or 2.8 MW (0.3 s, continuous collimation during bunch compression)
p-collimation
me
rgin
g
decay losses
inje
ctio
n1)+2)
3)