Developing LAr Scintillation Light Applications at Neutrino Energies - - PowerPoint PPT Presentation

Developing LAr Scintillation Light Applications at Neutrino Energies with LArIAT

Andrzej Szelc,

Manchester

(for the LArIAT collaboration)

24/09/17

• A. M. Szelc @ FAPESP DUNE workshop

2

What is LArIAT?

Reusing the ArgoNeuT detector with small modifications:

• front flange modified with excluder

+ Titanium window.

• Side flange modified to allow for

Light System.

• Bottom flange modified to enable

liquid recirculation (quicker purification). Run 1 completed. Run 2 completed. Run 3 completed.

A test facility to calibrate and test LArTPCs and their components using a beam of charged particles and a test-beam experiment.

More details in Ernesto Kemp's Talk

24/09/17

• A. M. Szelc @ LIDINE 2017

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Light Collection System

• Available photocathodic

coverage (and therefore choice of PMTs) limited by size of side flange.

• In a way a similar problem to

future large scale detectors.

24/09/17

• A. M. Szelc @ LIDINE 2017

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LArTPC

Solution – recover light falling on walls

Applying TPB to the reflective foil that will line the inside of the LArIAT TPC Wavelength shifting reflector foil

• First test of TPB

coated reflector foils in a running TPC (at beam neutrino energies).

Run I & II, Copper Cathode. Run III, mesh cathode with WLS foils installed.

24/09/17

• A. M. Szelc @ LIDINE 2017

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Foils

• LArIAT used VIKUITY ESR foils.

Possible to use DF2000MA.

• Excellent reflectivity in visible

wavelengths.

• Evaporation using LTE

Evaporator (300 ug/cm^2 thickness).

• Stable operation for 3

subsequent runs (3 years)

Measurements by B. Littlejohn, IIT, PROSPECT

24/09/17

• A. M. Szelc @ LIDINE 2017

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• U

s i n g L A r S

• f

t S i m u l a t i

• n

t

• l

s d e v e l

• p

e d t

• a

c c

• u

n t f

• r
• p

t i c a l f

• i

l s ( c h e c k e d b y s t a n d a l

• n

e c

• d

e ) t

• m
• d

e l d e t e c t

• r

r e s p

• n

s e .

Light Collection Uniformity

L A r I A T P h

• t
• n

M C L Y = 1 4 . 1 p e / M e V

T

• p
• d
• w

n v i e w S i d e v i e w

L A r I A T P h

• t
• n

M C L Y = 6 . 2 p e / M e V

T

• p
• d
• w

n v i e w S i d e v i e w

Beam Direction Beam Direction

Good uniformity in the detector. Enables new uses

• f scintillation light.
• W. Foreman

24/09/17

• A. M. Szelc @ LIDINE 2017

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Validating the Simulation

• Simplest topology –

easy to understand.

• Calculate energy from

range or dE/dx deposition.

• Compare with Light

collected by PMTs.

• More complex

topologies and protons (in progress). μ

+ /

• L

A r I A T P r e l i m i n a r y T h r

• u

g h

• g
• i

n g μ E T L ( 2 ” ) P M T

P . K r y c z y n s k i

24/09/17

• A. M. Szelc @ LIDINE 2017

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• M. Sorel JINST 9 (2014)

P10002

M C P r e d i c t i

• n

M C P r e d i c t i

• n

μ e n d p

• i

n t w i t h i n 1 5 c m

• f

T P C c e n t e r

• M

i c h e l

• c

a n d i d a t e s i g n a l s i n t e g r a t e d t

• g

e t P E s p e c t r u m

• M

C r e p r

• d

u c e s s h a p e w e l l . G i v e s m

• r

e c

• n

fj d e n c e i n s i m u l a t i

• n

m

• d

e l .

• L

Y c

• m

p a t i b l e w i t h t h r

• u

g h

• g
• i

n g m u

• n

s a m p l e .

• U

n i f

• r

m i t y g r e a t l y h e l p s

Energy Calibration with Michels

End goal: combine charge + light to get full energy reconstruction.

• W. Foreman

24/09/17

• A. M. Szelc @ LIDINE 2017

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Closing the loop: foils on the cathode

A way of putting foils on cathode without affecting electric field is to sandwich them in a mesh. A small mesh-cathode (SBND-like). was installed in LArIAT beginning of march.

24/09/17 SBND Collaboration Meeting, Sep. 2017 10

Mesh Cathode Runs

We performed two dedicated subruns with an SBND like cathode (with and without foils installed). No problems in TPC

• peration observed. Final

results in preparation.

BEFORE AFTER

24/09/17

• A. M. Szelc @ LIDINE 2017

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Delayed light in liquid argon

• Space charge effects in LArTPCs
• n the surface could manifest as

delayed scintillation light from recombining positive ions (see R. Santorelli talk).

• The positive ion drift velocity ~0.8

cm/s (@500V) leads to time scales much longer than typical LArTPC readout frames ( o(10s) vs o(ms) ).

• Impossible to correlate this light

with single events. Should instead manifest as extra “light noise”.

24/09/17

• A. M. Szelc @ LIDINE 2017

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LArIAT Beam Structure

4 sec 26 sec

• LArIAT has the benefit of a 4 – second beam spill

every 60 seconds. Coincidentally drift from anode to cathode at 0.8 cm/s is ~60 seconds.

• LArIAT should be able to tell us something if the ion

light is there. Charge injected into the system Time for positive ions to drift from anode to cathode at 500V Pulser Run Readout 56 sec

24/09/17

• A. M. Szelc @ LIDINE 2017

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Dedicated pulser runs

PMT calibration performed in-situ

• n tails of LAr scintillation events.

Single phel counting to obtain number of random phel.

• Several sets of dedicated

pulser runs taken.

• Random trigger,

28 us Waveforms.

• Looking for random light noise

24/09/17

• A. M. Szelc @ LIDINE 2017

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Preliminary Results

• Varying beam intensity and

E-Field (0 – 600V/cm)

• “Cosmic only” runs taken

at same voltages.

• We observe an effect
• f the beam spill.
• Analysis in progress –

have runs in different configurations, should be able to say some things about location.

PRELIMINARY PRELIMINARY

BEAM WINDOW

24/09/17

• A. M. Szelc @ LIDINE 2017

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Large foil production

• We now have

infrastructure needed to manufacture large evaporated surfaces (up to 60x60 cm2) at Manchester.

• Planned to be used

for SBND production, but we're interested in new projects.

• D. Garcia-Gamez

and F. Spagliardi with first LArIAT cathode foil.

24/09/17

• A. M. Szelc @ LIDINE 2017

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Summary

• LArIAT light collection system is a new approach

(at these energies).

• Smaller photocathodic coverage can be

compensated with WLS-covered foils.

• Enhanced uniformity enables calorimetric studies

and muon sign discrimination.

• LArIAT analyses on using light and combined light

+ charge for calorimetry, particle ID are in progress.

• Lessons learned instrumental in preparing

proposal to install foils on SBND CPA.

24/09/17

• A. M. Szelc @ LIDINE 2017

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Thank You for your Attention

24/09/17

• A. M. Szelc @ LIDINE 2017

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The LArIAT testbeam experiment is running in MCenter – allows long term occupation (as opposed to MTest).

Fermilab Testbeam Facility Fermilab Testbeam Facility

Main injector protons

Main Injector One 4s long spill per minute Secondary beam max 300k particles/spill

Secondary

MTest MCenter

24/09/17

• A. M. Szelc @ LIDINE 2017

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LArIAT Beamline

We will use a Tertiary beam (Similar to

MINERvA beam test). We want to study charged particles in the energy range relevant for future neutrino experiments. We can tune their energy by adjusting the parameters of the beamline,

Tertiary Beam at MCenter

Particles from ν interactions

NuMI LE on-axis

Tertiary Beam composition

24/09/17

• A. M. Szelc @ LIDINE 2017

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LArIAT Beamline

Optimized to study charged particles in the energy range relevant for future neutrino

• experiments. We can tune their

energy by adjusting the parameters of the beamline,

Particles from ν interactions

NuMI LE on-axis

Tertiary Beam composition

24/09/17

• A. M. Szelc @ LIDINE 2017

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Beamline Elements

• MWPCs
• TOFs

Magnets + TOFs + MWPC allow reconstructing momentum and PID of particles in the tertiary beam. Controlled sample of particles hitting the TPC.

24/09/17

• A. M. Szelc @ LIDINE 2017

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m vs p separation in beamline

24/09/17

• A. M. Szelc @ LIDINE 2017

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Example Waveforms

PMT calibration performed in-situ

• n tails of LAr scintillation events.

Single phel counting to obtain full light spectrum.

24/09/17

• A. M. Szelc @ LIDINE 2017

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Triggers

• Can use combination of triggers.

– LARSCINT – trigger on amplified

ETL signal (-12 mV)

– MICHEL – catch Michel

electrons/positrons (=next slides)

– SCINTGATE (400 us gate after

each LARSCINT)

– LARRY: muon “telescope”

• Coincidence of LARSCINT

with either of upper cosmic paddles.

• Catches both through going

and stopping muons.

1 1 6 H z a t 1 2 m V t h r e s h

T P C U p p e r c

• s

m i c μ p a d d l e μ μ

L I D I N E 2 1 5 P r

• c

e e d i n g s , J I N S T 1 1 C 1 3 7

D a t a s e t : ~ 1 2 d a y s

Muon absorption on argon

m- have a predicted 75% capture rate on argon nuclei (no Michel electron present).

• W. Foreman

Neutrino vs. anti-neutrino Statistical discrimination possible, e.g. in the DUNE far detector

• M. Sorel JINST 9 (2014)

P10002

24/09/17

• A. M. Szelc @ LIDINE 2017

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Time Projection Chamber