interaction length

Interaction Length

A. Murakami

• L = 38.83 (interaction length of proton in carbon by PDG)

• change of constant : means uncertainty of L (change 0.8, 0.9, 1.0, 1.1, 1.2)

• Flux is normalized at peak flux.

Normalized Flux @SK

There seems to be no difference...

Flux × 30 for looking at the tail

Flux × 15 for looking at the tail

Ratio of Normalized Flux @SK

zoom to 0~2 GeV

Diff. less than 3%

Diff. less than 5%

constant = 1.1, 1.2 vs 1.0

Ratio of Normalized Flux @SK

zoom around 0~2 GeV

Diff. less than 3%

Diff. more than 5%

constant = 0.9, 0.8 vs 1.0

Ratio of Normalized Flux @ND5

zoom around 0~2 GeV

constant = 1.2, 1.1 vs 1.0

Diff. less than 2%

Diff. less than 3%

Ratio of Normalized Flux @ND5

zoom around 0~2 GeV

constant = 0.9, 0.8 vs 1.0

Diff. less than 2%

Diff. less than 5%

Far / Near constant=1.0, 1.1, 1.2

zoom around 0~2 GeV

There seems to be no difference...

Far / Near constant=1.0, 0.9, 0.8

zoom around 0~2 GeV

There seems to be no difference...

Comparison of Far/Near constant=1.0, 1.1, 1.2

zoom around 0~2 GeV

Diff less than 2%

Diff less than 3%

Comparison of Far/Near constant=1.0, 0.9, 0.8

zoom around 0~2 GeV

Diff less than 2%

Diff less than 4%

Out-target/In-target comparison

A. MurakamiConfirmation of Nicolas’s study

Zoom

Zoom

Zoom

Zoom

Diff between “out” and “total”< 6%

Primary beam profile

A. Murakami

Black : nominal beam profileBlue : Flat beamRed : pencil beam

Y-Scale × 40

2020

ZOOM

2121

ZOOM

2222

ZOOM

2323

ZOOM

24

Z binning studybinning target exit z position

A. Murakami

25

Simple simulation by

either geant3, mars, fluka, geant4 ……

Target is just a 90cm, 2.6cm-diameter rod.

Vector information of particles just exit the target is output.

Normal use for model comparison30GeV proton In jnubeam

Generate and trace the track inputted.

Vector

information

Simple simulation by geant3

Target is just a 90cm, 2.6cm-diameter rod.

Vector information of particles just exit the target is output. But ‘z’ value is modified to simulate the binning condition.

This study30GeV proton In jnubeam

Generate and trace the track input.

Vector

information‘one bin’ case

12/)sizebin (z

2727

2828

2929

ZOOM

3030

ZOOM

31

Secondary interaction in Horn Aluminum

A. Murakami

32

Super-K ND off-axis

Red: remove horn aluminumBlack : nominal

3333

3434

3535

3636

ASSUMED condition(ad hoc)

Abs. flux

Flux shape

Far/Near

Trans. Matrix

remakes

primary Gfluka v.s. gheisha

35% <10% Sakashita

primary Gfluka v.s. K2K-SW

30% 10% Sakashita

Prod. Point (Z) Dz=18cm(=18/sqrt(12))

4% 3% Murakami

Interaction length 20% 7% 4% Murakami

Second. Had.prod. Gfluka v.s. gclaor

15% <3% Sakashita

Sec. intr. in horn Al 20% uncertainty

6%6%

2%2%

Murakami30% absorption

Out target inter. 20% uncertainty

5%5%

2% Nicolas/Murakami10~30% out of total

Indirect contr. Nicolas

Upper number: 0.4<En<1.2GeV regionLower number : En<10GeV

Prim

ary

inte

racti

onSe

cond

ary

Inte

racti

on

Upper number: 0.4<En<1.2GeV regionLower number : En<10GeV

Cont’d

ASSUMED condition(ad hoc)

Abs. flux

Flux shape

Far/Near

Trans. Matrix

remakes

Pbeam profile No profile info. 10%12%

5% Murakami

Pbeam position shift

Josh

Pbeam angle shift

Horn alignment Josh

Horn current Josh

Horn field asym. 10% 8% Eric

Prim

ary

Beam

Horn