harold g. kirk brookhaven national laboratory target considerations for nufact and superbeams iss...
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Harold G. KirkBrookhaven National Laboratory
Target Considerations for Nufact and Superbeams
ISS Meeting
RAL April 26, 2006
Harold G. Kirk
Main Study Parameter
Design for:
4 MW
Harold G. Kirk
Driving Target Issues
Meson Production Proton Beam Pulse Length Proton Beam Structure
Harold G. Kirk
Stephen Brook’s Analysis
Pions counted at rod surface
B-field ignored within rod (negligible effect)
Proton beam assumed parallel Circular parabolic distribution, rod radius
20cm
1cmSolid Tantalum
Protons
Pions
Harold G. Kirk
Yield of ± and K± in MARS
2.2
Ge
V
3G
eV
4G
eV
20
Ge
V
30
Ge
V
40
Ge
V5
0G
eV
75
Ge
V
10
0G
eV
12
0G
eV
15
Ge
V
10
Ge
V
8G
eV
6G
eV
5G
eV
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
1 10 100 1000
Proton Energy (GeV)
Pio
ns
or
Ka
on
s p
er
Pro
ton
.Ge
V (
tota
l e
mit
ted
)
pi+/(p.GeV)
pi-/(p.GeV)
pi+/(p.GeV)pi-/(p.GeV)
K+/(p.GeV)
K-/(p.GeV)
•No surprises in SPL region•Statistical errors small•1 kaon 1.06 muons
Finer sampling
Harold G. Kirk
The Study 2 Capture Concept
Maximize Pion/Muon Production Soft-pion Production High Z materials High Magnetic Field Solenoid
Harold G. Kirk
The Study2 Target System
Consider Liquid Hg
Count all the pions and muons that cross the transverse plane at z=50m.
For this analysis we select all pions and muons with KE< 0.35 GeV.
Harold G. Kirk
Optimize Soft-pion Production using Hg
Harold G. Kirk
Meson KE < 350 MeV at 50m
Mesons/Proton Mesons/Proton normalized to beam power
Harold G. Kirk
Process mesons through Cooling
Consider mesons within acceptance ofε┴ = 30π mm and εL = 150π mmafter cooling
350 MeV
Use meson count with KE < 350 MeVas a figure of merit.
Harold G. Kirk
Post-cooling 30π Acceptance
Harold G. Kirk
Carbon Target Parameters Search
Harold G. Kirk
Carbon Target Optimization
Set R=1.25cm; tilt angle = 50 mrad; Length=60cm; Z=-40cm
Harold G. Kirk
Proton KE Scan with Carbon
Count mesons within acceptance of
ε┴ = 30π mm and
εL = 150π mm
after cooling
Harold G. Kirk
Summary of Results
Compare Meson production for Hg at 24 GeV and 10 GeV
Compare Meson production for C at 24 GeV and 5 GeV
Compare Meson production for Hg at 10 GeV and C at 5 GeV
GeV
GeV
N
N
24
10
GeV
GeV
N
N
24
101.07 1.10
GeV
GeV
N
N
24
5
GeV
GeV
N
N
24
51.90 1.77
GeVC
GeVHg
N
N
5
10
GeVC
GeVHg
N
N
5
101.18 1.22
Harold G. Kirk
Conclusion
Optimum Input Proton Beam Energy for Study2a configuration with Hg: 8 to 20 GeVSuperbeam proton beams energies:Mini-boone 8GeVBNL AGS 28 GeVJpark 30 to 50 GeVNumi 60 to 120 GeVCNGS 400 GeV
Harold G. Kirk
Driving Target Issues
Meson Production Proton Beam Pulse Length Proton Beam Structure
Harold G. Kirk
Proton Beam Pulse Length
Study 2a J. Gallardo, H. Kirk
Harold G. Kirk
Conclusion
Optimum Proton Beam Pulse Length for Study2a configuration: 1nsSuperbeam proton beams energies:BNL AGS 28 GeV 10nsNumi 4 μsCNGS 2 x 5 μs
Harold G. Kirk
Driving Target Issues
Meson Production Proton Beam Pulse Length Proton Beam Structure
Harold G. Kirk
Protons per pulse required for 4 MW
10 Hz 25 Hz 50 Hz
10 GeV 250 × 1012 100 × 1012 50 × 1012
20 GeV 125 × 1012 50 × 1012 25 × 1012
]Hz[feN]eV[E)w(Prep
arc
Proton Beam Intensity
Harold G. Kirk
Shock Stress Analysis N. Simos
Harold G. Kirk
SUMMARY of Performance
1 MW/50 Hz
12.0 e+12 ppp
YES
4 MW/50 Hz
48.0 e+12 ppp
NO
1 MW/200 Hz
3.0 e+12 ppp
YES
4 MW/200 Hz
12.0 e+12 ppp
MAYBE
Solid Targets
Harold G. Kirk
5 X 50 Proton Beam Structure
Johnstone, Meot, Rees 10 GeV Proton Beam 50 Hz n = 5 sub-structure => 10 x 1012 protons (10TP) per micro-bunch Accelerate 3 to 10 GeV with harmonic 36 structure and frequency of 13.079-13.417 MHz Adiabatically compress to 2ns Further compress to 1ns with f=80.5 MHz and f=201.25MHz
Harold G. Kirk
Pulse Delivery to Target
ΔT = 13 μs => 52 μs bunch structure
Liquid Target
ΔT = 65 μs => 260 μs bunch structure
Solid Target
Harold G. Kirk
Muon Bunch Pattern in Decay Rings
.
148(133)
solid/liquid
80 μ+
80 μ+
80 μ+
80 μ+
80 μ+
127(!30)
127(130)
127(130)
127(130)
2 of 5 interleaved 80 μˉ
bunch trains of 2nd ring
80 full and 127 (or 130) empty RF buckets
> 100ns intervals