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Calculating Fluences from track records and comparing to MPX data

KOI, TatsumiSLAC National Accelerator Laboratory

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Calculating Fluences from track records

• L = • V = Volume of Scoring Volume• Fluence [1/cm2]

= L [cm]/ V[cm3]• No need for limitation in

scoring volume shape• No need for assumption

in directional distribution of track

Track A

Track B

A Scoring VolumeSegment A

Segment A’

Segment B

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Calculating Fluences from track records

• Each of our track record has– Entering point – Direction at the point– ID of scoring volume

• Calculating escaping point from the scoring volume

• Calculating distance between these two points– Assuming no interaction

happen between them

Track A

Track B

A Scoring VolumeSegment A

Segment A’

Segment B

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Calculations

• FLUGG Tag 00-01-31– Last tag before winter breaks

• Input event– Minimum bias PHOJET 7TeV– 9984 events calculated

• 1MeV cut for electrons• Disable Radioactive Decay

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Location of MPX detectorsMPX1 and MPX14 MPX2 and MPX13 are located in symmetrical positions

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Thermal neutron (<0.3eV) fluences MPX data and G3 calculation from Jaroslav 11/21/2011

MPX1

MPX2

MPX14

MPX13

MPX1 and MPX14 MPX2 and MPX13 are located in symmetrical positions

100mb is used for the cross section of pp collision at 7TeV to keep a consistency to the Jaroslav results

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Thermal Neutron (<0.3eV) Fluences

Scoring Volume for each MPX has 1cm thickness in R and Z

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Anisotropyz-distribution of directional vectors

MPX 1 and 14 MPX 2 and 13

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Anisotropy MPX3,4,5,6z-distribution of directional vectors

Need more events

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Anisotropy MPX15z-distribution of directional vectors

Neutron Energy SpectrumMPX1 and 14

MeVeV

Neutron Energy SpectrumMPX2 and 13

eV MeV

Neutron Energy SpectrumMPX15

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MPX datafrom Jaroslav 11/21/2011

MPX1

MPX2

MPX14

MPX13

MPX1 and MPX14 MPX2 and MPX13 are located in symmetrical positions

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FLUGG Calculation

MPX1 MPX2 MPX3 MPX4 MPX5 MPX6 MPX7 MPX8 MPX9 MPX10 MPX11 MPX12 MPX13 MPX14 MPX151.0E-03

1.0E-02

1.0E-01

1.0E+00

1.0E+01

1.0E+02

1.0E+03

1.0E+04

1.0E+05

1.0E+06

1.0E+07

thermal neutronelectronsprotonsmuons

fluen

ces [

/cm

2]

Statistical limitation on 10k events

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Comparison between data and FLUGG(MC) Electrons, protons and muons

Electrons have 1MeV energy cuts in simulation

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Summary• There are relatively large differences in fluences estimation at MPX1 and 14

between this work and previous work (Jaroslav) This may come from anisotropy of thermal neutrons at the positions– This may come from anisotropy of thermal neutrons at the positions ( – Agreements to the data are improved but most likely by chance. Because the data

analysis assumed isotropic neutron fluences.• Our result and Mike’s calculation agree within a few factors for all MPXs.• Relatively large difference between calculations and data for MPX7-11,

where has low rate in thermal neutron flux.• Energy Spectrum of neutrons are different among the position of MPX

– MPX15 has a much different spectrum from others– Does data analysis properly include this?

• We also calculate fluences for electrons (e-+), proton(p/anti-p) and muosn(mu+-) and compare to the data.

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Number of thermal neutron (<0.3eV) tracks in each MPX Scoring Volume

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Number of electrons (e-/e+) tracks in each MPX Scoring Volume 1MeV Cut

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Number of protons (p / anti-p) tracks in each MPX Scoring Volume

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Number of muons (+/-) tracks in each MPX Scoring Volume