HES Simulation Status Report

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HES SimulationStatus Report

• contents
• Summary of last Meeting
• Progress in this 2 month

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1.Summary of last Meeting
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3rd Exp. Setup
EDC EHodo
Now Constructing(by TOKIN)
HES
Window Frame
HKS
Target
1.0GeV e
Splitter
1.2GeV K
CEBAF 2.5GeV Electron Beam
1m
4
HES-HKS momentum acceptance
MC Simulation by Geant4
51LTi g.s
S
L
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Tilt Angle optimization
Definition
Signal VP event (QQD passed) Noise Brems or
Moller event (QQD passed)
Assumption define the relation between Offset
and Tilt Angle
yt?Tilt Angle yt?Offset
Tilt Angle?Offset
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FoM vs Tilt Angle
Tilt Angle vs FoM
Select
Select
550 MeV/c
967 MeV/c
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HES Solid Angle
Enge SA 5msr
967 MeV/c
550 MeV/c
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VP Rate
Assumption 100mg/cm2 12C target, 20uA beam,
s?100 nb/sr HKS Solid Angle
0.008 rad , Kaon Decay Rate 0.3
Enge 0.1
967 MeV/c
550 MeV/c
Integral 1.74 /sec/sr
Integral 0.521 /sec/sr
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Yield Estimation on several target
HKS-HES matching is Not considered

• Beam Intensity 30µA?Target Thickness 100
  mg/cm2
• Cross Section of Hypernuclei 100 nb/sr
• HKS SA E05-115 ? 9 msr? E01-011 ? 16 msr

Target VP Rate Hz Kaon Rate Hz L hypernuclei yield 1/hour L hypernuclei yield 1/hour
Target VP Rate Hz Kaon Rate Hz E05-115 E01-011
6Li 1.5102 93 150 19
7Li 1.5102 88 130 16
9Be 1.6102 99 100 12
10B 1.5102 89 92 11
12C 1.6102 94 77 9.6
28Si 1.8102 100 33 4.1
51V 1.0102 63 18 2.2
89Y 1.1102 67 10 1.3
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• 2. Progress in this 2 month
• EDC position Study
• HES momentum resolution

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About Detector Plane

• There are no difference in resolution between
  rotated Detector Plane (hardware Spectrometer)
  and non-rotated Detector Plane (software
  spectrometer)

Apply non-rotated Detector Plane
EDC
D.P

• Outside Detector Plane has very bad pos.
  resolution (even in the case of no M.S.)

EDC

• Detector Plane(EDC) should be placed as far
  from ED as possible

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By _at_ ED Exit
By (gauss)
FP3 1m from ED FP1 52cm from ED
Distance from ED (cm)
immediate after ED coil End of vacuum extension
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FP Beam Profile
1m from ED
1.5m from ED
91.1
90.2
dispersion 1.69 m/d
dispersion 2.06 m/d
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EDC Position
81cm
new vacuum extension
new vacuum extension?
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EDC Resolution _at_ 967 MeV/c
Included Material
Gas ArC2H6 32.0 cm
Window Al Mylar 12.5mm2
No wires are included
EDC Resolution (by Geant4)
EDC Resolution (measured in LNS, 300MeV/c)
Plane resolution 210mm
sx 85.7 mm
sx 0.695 mrad
sy 212 mm
sy 2.80 mrad
sx 86 mm
sx 0.7 mrad
sy 210 mm
sy 2.8 mrad
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HES resolution right now
Fujiis method works good! ? Use
gaussian-distributed FP value (s half of EDC
resolution )

• Condition
• EDC is placed at 1.5m from ED
• 8th order Matrix
• Strange shape is not separated in Matrix
  calculation

Dont Care
s2.410-4
corresponds to 400keV (FWHM) in MM resolution
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ED TOSCA MAP is wrong!?
There are some strange shape in ED TOSCA MAP
cause wrong resolution?
(still in investigation)
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Strange Shape Separation
Red XFP3lt0 Blue XFP3gt0
Cut -1. lt EYFP3 lt 1. cm
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For XFP3gt0 Resion
Red EXpFP3gt0.1 mrad Black All XFP3gt0 Event
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For XFP3lt0 Resion
Red EXpFP3lt-0.1 mrad Black All XFP3lt0 Event
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Resolution w/ strange shape cut

• dp (pr-p) (prreconstructed momentum)
• No EDC, No multiple scattering (only Matrix
  resolution)
• EXFP3gt0 (cm) -0.05ltEXpFP3lt0.05 (rad)

dp/p (10-4)
Improved from 1.010-4 (no cut value)
s0.6610-4
xt (mrad)
yt (mrad)
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What is the source ?
Q1 Exit Profile for EXFP3lt0
Red EXFP3lt0 EXpFP3lt-0.1 Blue EXFP3lt0
ExpFP3gt-0.1
Q1 Exit Profile for EXFP3gt0
Red EXFP3gt0 EXpFP3gt0.1 Blue EXFP3gt0
ExpFP3lt0.1
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What is the source ?
Q1 Exit Profile for EXFP3lt0
Red EXFP3lt0 EXpFP3lt-0.1 Blue EXFP3lt0
ExpFP3gt-0.1
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What is the source ?
Q1 Exit Profile for EXFP3gt0
Red EXFP3gt0 EXpFP3gt0.1 Blue EXFP3gt0
ExpFP3lt0.1
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Summary Next

• EDC should be placed on 135cm from ED exit and
  we need new vacuum extension.
• Now HES resolution w/ EDC is 2.410-4 (RMS)
  which corresponds to 400keV (FWHM) MM
  resolution.

• Next to do
• 1. HES Resolution Study w/ EDC
• Check TOSCA Field Map
• Place HDC ?
• Tilt Angle dependence
• 2. Tilt Angle optimization
• 3. Sieve Slit Analysis