Beam MC progresses for beam MC sub-group

Summary of update in 09b,c,10a 09b Geometry of baffle, target, 1st horn, dump and MUMON is updated. 09c MUMON structures were included. Energy deposit in the MUMON detector can be stored. Emittance and Twiss parameters via card. 10a to be released soon Horn2&3 geometry update Mag. field inside inner conductor Store primary proton vector information to enable weighting method New ND280 flux algorithm Store particle interaction history K ± µ3 and K 0 µ3 decay for neutrino Random number generation seeds control

Comparison among different versions K. Matsuoka

T2K horn effect (jnubeam 09c) X9.4x16 On-axisOff-axis A.K.Ichikawa

Horn Magnetic Field How should we treat the magnetic field inside the inner conductor? Horn1 inner conductor Inner radius = 2.7cm, outer radius=3cm Assuming that the elec. current is uniform in the conductor, (skin depth > 5mm) Significant effect on MUMON signal was found Modest effect on neutrino flux K. Matsuoka r B Inner conductor Realistic. B-field

2D Gaussian fitPeak flux (/cm 2 )*  x (cm)  y (cm) Max. B-field(8.74 ±0.03 ) x ± ±0.9 Realistic B-field(8.09 ±0.03 ) x ± ±1.0 Min. B-field(7.41 ±0.03 ) x ± ±1.0 0 kA(1.48 ±0.02 ) x ± ±10 (* per 3.3 x POT) 8~9% effect. (difference from realistic B field) mag. field inside inner conductor -MUMON, all horns on- Max. B-field 1/r-shape field starts from inner surface of the inner conductor Min. B-field starts from the outer surface of the inner condcutor

mag. field inside inner conductor E spectra (SK) Red: Max. Black: Realistic Blue: Min. Red: Max./realistic Blue: Min./realistic <3% effect (need more statistics) All 

mag. field inside inner conductor E spectra (ND on-axis) (Error bars may be under-estimated.See later slides.) All  Red: Max. Black: Realistic Blue: Min. Red: Max./realistic Blue: Min./realistic

mag. field inside inner conductor INGRID profile All  Red: Max. Black: Realistic Blue: Min. All  Red: Max. Black: Realistic Blue: Min. abs(x) ≤ 5.5 m && abs(y) ≤ 0.5 m ND2 abs(x) ≤ 0.5 m && abs(y) ≤ 5.5 m Due to the magnetic field in the inner conductors, flux at ND on the axis gets sharper than that of 09c (min B-field). Peak value: (min) 5.66 x  (realistic) 5.79 x /m 2 /10 21 POT

Horn2 and Horn3 Geometry update update from conceptual shape to real shape Horn2 – outer conductor radius : 40 cm -> cm – B-field region (Z-length) : 200 cm ->199.7 cm Horn3 – outer conductor radius : 70 cm  65.5 cm H.Kubo

Horn2&3 geometry update muon (Si-plane, horn 320kA) flux decreased by 3%, profile shape is same muon peak flux (cm -2 ) sigma X [cm]sigma Y [cm] 09b7.2 x ± 1104 ± 1 new horn geom.6.9 x ± 1105 ± 1 3horns, 11 POT

Horn2&3 geometry update neutrino flux 09b new Far/Near less than 5% difference upto 5GeV

Parents of muons in muon pit -pions- H.Kubo. K.Matsuoka Horn off 1 st Horn 273kA All horns 320kA

Parents of muons in muon pit -kaons- H.Kubo. K.Matsuoka Horn off 1 st Horn 273kA All horns 320kA

Parents of muons in muon pit -K/pi ratio- entries (/5x10^7 POT) Ratio (K / Pi) horn current pion (+/-) K(all)K0K+K- K(all)K0K+K- 0kA kA, 1st horn only kA, 3horns

Proton information Store primary beam information Accumulate POT w/ a flat proton beam and weight t w/ an arbitrary proton profile to simulate that profile No need to make many MC data sets of various proton beam profile. K. Matsuoka x (mm)  x (mm) Peak flux (/cm 2 )*x (cm)y (cm)  x (cm)  y (cm) Weight03.6(2.81 ±0.02 ) x ± ± ±4 129 ±3 Normal03.6(2.84 ±0.02 ) x ± ± ±4 132 ±4 Weight53.6(2.84 ±0.02 ) x 10 4 –4.3 ± ± ±6 128 ±3 Normal53.6(2.87 ±0.02 ) x 10 4 –7.9 ± ± ±6 128 ±3 Weight51.7(2.82 ±0.02 ) x 10 4 –11.8 ± ± ±9 128 ±4 Normal51.7(2.83 ±0.02 ) x 10 4 –8.9 ± ± ±5 132 ±4 Demonstration w/ MUMON profile  y : 1.7 mm (*  +– /3.4 x POT)

Production history Fill ntuples with neutrino history, taking decay chains into account. – information of primary, secondary,... interactions) Include additional decay modes for pions and kaons, updated branching ratios – π ± → e ± ν e – K ± µ3 and K 0 µ3 – neglect K0S semileptonic decays ? (e.g. K2K case) N. Abgrall

new ND flux calculation algorithm current filling routine – SK : treated as a “point”. for every decay of  /K/ , neutrino is forced to go towards SK probability is calculated and stored as “norm”. – ND : repeat parent’s decay randomly (uniformly in CM) by 1,000 times only neutrinos which have proper angle are filled. New method : same method as SK case. 1.choose a detection point (x, y) randomly in the ND plane 2.calculate weight (acceptance) for this direction Motivation – In the current version, high-energy pions are multiply used. Events are not independent. Simple error couting results in underestimate. H.Kubo

Enu spectrum seems to be consistent χ 2 = 19.7 / 39 – to small – due to using same set of parents ?

error histogram (Enu) low energy (< 1GeV) : same or smaller error Original method had been giving underestimated error original new

on-axis xnu (fitting) fit with Gaussian – large chi2 & mean offset (10 sigma) in original algorism indicates under estimation of error originalnew χ 2 / ndf867 / / 17 mean-1.57 ± 0.16 cm-2.0 ± 3.5 cm sigma568 ± 0.4 cm556 ± 8 cm originalnew

Other activity Detailed check of dimensions by P.Perio Treatment of Random numbers – M.Hartz, K.Sakashita – code is modified to select 215 good seed-pairs for GRNDM by K.Sakashita d=2&resId=0&materialId=slides&confId=155 OTR simulation by OTR group Target scan simulation – K.Matsuoka, M.Hartz CPU saving effort Review on gcalor (secondary interaction model) Review on INGRID study A.Minamino

Prospect Flux Mass production Received requests from ND280 beam group Need to be done – Implementation of the correct ND280 position – Optimization of proton beam area two flat area? – Release 10a In Next week at 250kA horn current Remaining update Striplines Transfer matrix with new ND280 algorithm Inclusion of NA61 results w/ NA61-T2K group And studies.

Other geometry update MUMON structure has been added. Geometry of the collimator at the entrance of DV has been update based on the measurement. The size of the DV entrance has been changed based on the measurement. Density of dump material – concrete from 2.2 to 2.3 g/cm3 ~1% effect on MUMON – concrete rebars 2.3g/cm3 -> g/cm3 <1% effect on MUMON

mag. field inside inner conductor -MUMON,1 st horn only- Primary proton profile  x= 0.36,  y= 0.17 (mm) Only Horn1 same as April ’09 commissioning Peak flux*  x(cm)  y(cm) 273 kA (min.B-field)(2.76+/-3) x /-6131+/ kA (realistic B-field)(2.99+/-3) x /-5121+/ kA (max. B-field)(3.15+/-3) x /-4120+/-4 0 kA(1.53+/-2) x / /-10 (*per 3.4x10 11 POT, 2D fit peak) A few % effect

Horn2&3 geometry update pion production point (mumon) horn1 horn2 horn3 horn1 horn2 horn3 dump target & horn1 ( -510 < Z < -350) horn2 (-300 < Z < -100) horn3 (350 < Z < 650) b new 10 3 entries / 5.0 x 10 7 POT

Horn2&3 geometry update effect of horn2&3 material total(<10GeV)peak(/50MeV) w/Horn2&3 material1.21x x10 6 w/o horn2&3 material1.33x x10 6 absorption ~ 10% peak) less effect than horn1

Horn2&3 geometry update pions whose daughter muons goes through mumon Si-plane horn 320kA horn [kA]chargedmuons 0, 0, , 0, , 320, , 320, particle flux [10 4 / cm 2 / 3.4 x Si-plane ( peak of X projection-fit )

Muon flux at muon pit Emulsion v.s. MC A.Ariga et. al.

Comaprison Emulsion, Si, MC 31 Horn current Shot # Proton (CT05) Emulsion (trk/cm 2 ) Si (pC) Em/Si (trk/pC) MC July Em/MC July MC Sep Em/MC Sep MC 09c Emu Em/MC 09c Emu 273kA x x x x x kA x x x x kA x x x x x Proton : from beam summary (result_run24.root) Emulsion : cutoff 0.05GeV/c,  <0.3rad Si : using only 1 line (7 sensors) which corresponds emulsion modules. MC : muon, position at emulsion, momentum>0.05GeV/c,  <0.3rad normalized by Proton(CT05). Normalized at POT=3.4e11

Target scan M.Hartz Data for y scan

Review on gcalor Consists of : – NMTC : nucleons < 3.5GeV, π±< 2.5GeV – SCALE : Scaling Model (3GeV to 10GeV) – MICAP : neutron < 20MeV – (FLUKA) : >10GeV & other particles NMTC & Scaling For nucleons below 3.5GeV and π±below 2.5GeV, NMTC is used. Above 10GeV, FLUKA is used. Scaling energy range (3-10GeV) – FLUKA or (scaled)NMTC is called for each interaction with a linear probability function for smooth transition H.Kubo For more details,