Meson Production of Carbon Target at 3 GeV

X. Ding, UCLA

Target Studies

17/18/13

Carbon target with a tilt angle to SC solenoid axis

• Fieldmap: (IDS120h, 13.2m, 20T1.5T)• Carbon target with a cylindrical shape (or rod). Nuclear

Interaction Length (42.9 cm). • Rod with a small tilt angle to SC Solenoid axis. Initial

setting of target radius at 0.75 cm. Initial setting of tilt angle at 50 mrad.

• Collection: (50m downstream, 40MeV<KE<180MeV)• Proton Beam: KE at 3 GeV and launched at z=-100 cm.

Beam/target intersection point at z=-37.5 cm.

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Meson Production vs Target Length on Solenoid axis

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Target radius: 0.75 cmBeam radius: 0.1875 cmBeam angle: 50mradCrossing angle: 0 mrad

Peak value of fit: 72 cm

Meson Production vs Target Radius

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Rod length on SC axis: 72 cmCrossing angle: 0 mrad

Beam angle: 42mradTarget radius=4*beam radius (TR/BR=4.0)

Beam angle: 42mradTarget radius=3.5*beam radius (TR/BR=3.5)

Beam angle: 44mradTarget radius=2.5*beam radius (TR/BR=2.5)

Meson Production vs Target Radius

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Rod length on SC axis: 72 cmBeam angle: 42mradCrossing angle: 0 mradBeam radius: ¼ target radius

Peak value of fit: 0.323 cm

Meson Production vs Beam Angle

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Rod length on SC axis: 72 cmCrossing angle: 0 mrad

Target radius=0.346cm (TR/BR=4.0)

Target radius=0.35cm (TR/BR=3.5)

Target radius=0.40cm (TR/BR=2.5)

Meson Production vs Beam Angle

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Target radius: 0.346 cmTarget length: 72 cmBeam radius: 0.0865 cm(¼ target radius)Crossing angle: 0 mrad

Peak value of fit: 41 mrad

Energy Spectrum

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Carbon Target at 3GeV:Target length: 72 cmTarget radius: 0.365 cmBeam radius: 0.09125 cmBeam angle: 50mradBeam/target crossing angle: 0 mrad

Mercury Target at 8GeV:Target radius: 0.404 cmBeam radius: 0.1212 cmBeam angle: 117mradJet angle: 137.6 mradBeam/Jet crossing angle: 20.6 mrad

Energy Spectrum (Cont’d)

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PT Spectrum

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Comparison of Production

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At 3 GeV, Carbon gives more production than Ga or Hg.

Summary

• Optimized target parameters for carbon target at 3 GeV: Target length on SC axis/72 cm, target radius/0.346cm, beam radius/0.0865cm, Beam angle/42 mrad, Crossing angle/0 mrad.

• At 3 GeV, Carbon target can gives more meson production than Ga or Hg.

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IDS120j Geometry

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Meson Production (IDS120j)(Unit: Meson/proton/GeV)

MARS FLUKA

Carbon 3 GeV 0.02606 0.02969(neg: 0.01173, pos: 0.01796)

Gallium 3 GeV 0.02361 0.025(neg: 0.0113, pos: 0.0137)

Mercury 3 GeV 0.02059 0.0234(neg: 0.01207, pos: 0.01133)

Mercury 8 GeV 0.04108 0.026(neg: 0.01369, pos: 0.01231)

Gallium 8 GeV 0.03647 0.02656(neg: 0.01302, pos: 0.01354)

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Production of MARS vs FLUKA

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FLUKA (Average) FLUKA(Sum), MARS(Sum)

FLUKA (IDS120j)

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MARS (IDS120j)

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BACKUP

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Meson Production vs Crossing Angle

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Target length: 72 cmTarget radius: 0.346 cmBeam radius: 0.0865 cm(¼ target radius)Beam angle: 42 mrad

Peak value: ~ 0 mrad

Meson Production vs. Beam Radius

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Target length: 70cmTarget radius: 0.62 cmBeam angle: 50 mradCrossing angle: 0 mrad

Peak value: Beam radius smaller than a factor of 0.32 of target radius (<=0.20 cm) is favored.

PT Spectrum

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