Optymalizacja SMRDOptymalizacja SMRD

Paweł Przewłocki Paweł Przewłocki Warszawska Grupa NeutrinowaWarszawska Grupa Neutrinowa

Eksperyment T2K (Tokai2Kamioka)Eksperyment T2K (Tokai2Kamioka)

Akcelerator, tarcza grafitowa

tunel rozpadowy

Monitor mionów

Stacja ND280

Stacja 2kmSuperKamiokande

ND280 off-axis

N-GRID on-axis

p

140m0m 280m 2 km 295 km

Start: 2009Start: 2009

The problemThe problem

Side Muon Range Detector – measures muon Side Muon Range Detector – measures muon direction and momentum direction and momentum

Important for neutrino interactions and cosmic-Important for neutrino interactions and cosmic-ray muons (for calibration)ray muons (for calibration)

We have 15 layers of gaps suitable for We have 15 layers of gaps suitable for scintillator slabsscintillator slabs

But the number of slabs is limited. Therefore we But the number of slabs is limited. Therefore we have to optimize their configuration in order to have to optimize their configuration in order to maximize our measurement capabilities.maximize our measurement capabilities.

Nd280 off-axis detector – side viewNd280 off-axis detector – side view

1 2 3 4 5 6 7 8Rings:

15 layersPOD TPC TPC TPC

Front viewFront view

Left lateral part Right lateral part

Upper part

Bottom part

Our ends…Our ends…

Cosmic-ray muon considerations – Piotrek’s Cosmic-ray muon considerations – Piotrek’s presentationpresentation

My area of interest –measurement of muons My area of interest –measurement of muons from neutrino interactionsfrom neutrino interactions

Muons are mainly measured by TPC – SMRD is Muons are mainly measured by TPC – SMRD is important for events that cannot be handled by important for events that cannot be handled by TPCTPC

Question: what is the optimal SMRD layout to Question: what is the optimal SMRD layout to measure muons that cannot be seen in TPC?measure muons that cannot be seen in TPC?

……And meansAnd means

Let’s look at the numbers of the outermost Let’s look at the numbers of the outermost layer reached by muons that are of our layer reached by muons that are of our interestinterest

The tools:The tools: Geant4 ND280MC simulationGeant4 ND280MC simulation Input: NEUT files on water (for the time being)Input: NEUT files on water (for the time being)

Outermost layer in SMRDOutermost layer in SMRD

60.000 events from FGD60.000 events from FGDEnergy deposition cut – must have at least 0.5MeV to be a Energy deposition cut – must have at least 0.5MeV to be a valid hit valid hit TPC distance cut – muon has to travel maximum 60cm in TPC distance cut – muon has to travel maximum 60cm in TPC (longer tracks are reconstructed in TPC and don’t TPC (longer tracks are reconstructed in TPC and don’t need any additional info from SMRD)need any additional info from SMRD)„„QE” events definition:QE” events definition:

One muonOne muon No pizerosNo pizeros No pipluses over 200MeV in energyNo pipluses over 200MeV in energy

In some cases I split the SMRD intoIn some cases I split the SMRD into lateral and upper/bottom parts to lateral and upper/bottom parts to show the influence of the coil show the influence of the coil (present only on top and bottom (present only on top and bottom of the basket) of the basket)

Outermost layer distributionOutermost layer distribution60cm TPC distance cut applied

Red – lateral smrdBlack – lateral + upper/bottom

Lateral parts are more populated

All

QE

Lateral

Lateral + upper/bottom

Lateral

Lateral + upper/bottom

Outermost layer - upper vs bottom Outermost layer - upper vs bottom

60cm TPC distance cut appliedOnly bottom/upper part of smrd

Red – bottom smrdBlack – upper+bottom

Much more tracks go to the bottom part

Some statisticsSome statistics

All: Percentages with respect to All: Percentages with respect to allall mu CCmu CC events events

QE: percentages with respect to QE: percentages with respect to all mu CC qeall mu CC qe evts evts

Outermost Outermost over 4over 4

Outermost Outermost over 5over 5

Outermost Outermost over 6over 6

allall 2.94%2.94% 2.11%2.11% 1.53%1.53%

With 60cm TPC distance cut appliedWith 60cm TPC distance cut applied 1.97%1.97% 1.43%1.43% 1.02%1.02%

With distance cut applied, only rings #7 With distance cut applied, only rings #7 and 8and 8

1.6%1.6% 1.19%1.19% 0.87%0.87%

Outermost Outermost over 4over 4

Outermost Outermost over 5over 5

Outermost Outermost over 6over 6

allall 2.16%2.16% 1.44%1.44% 0.94%0.94%

With 60cm TPC distance cut appliedWith 60cm TPC distance cut applied 1.48%1.48% 1.02%1.02% 0.67%0.67%

With distance cut applied, only rings #7 With distance cut applied, only rings #7 and 8and 8

1.15%1.15% 0.83%0.83% 0.55%0.55%

Conclusions – proposed module Conclusions – proposed module distributiondistribution

Table prepared by Thomas Kutter based on results presented here and some other studies

BackupBackup

Incoming nu energy distributionsIncoming nu energy distributions

Black – all eventsRed – with 60cm TPC dist cut appliedBlue – as above + reaching smrd

All

QE

Incoming nu energy distributionsIncoming nu energy distributions

Black – TPC dist cut + reaching smrdRed – at least 4 layersBlue – at least 5 layersGreen – at least 6 layers

All

QE