Detector R&D: status and priorities Paolo Strolin NUFACT05 June 26, 2005 Low-Z Tracking Calorimetry...

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Detector R&D: status and priorities Paolo Strolin NUFACT05 June 26, 2005 Low-Z Tracking Calorimetry Magnetised Iron Spectrometers Water Čerenkov Liquid Argon TPC Emulsion Cloud Chamber Main issues in launching the Scoping Study on a -factory and super-beam facility Some of the detectors also for astro-particle physics
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Transcript of Detector R&D: status and priorities Paolo Strolin NUFACT05 June 26, 2005 Low-Z Tracking Calorimetry...

Detector R&D: status and priorities

Paolo StrolinNUFACT05

June 26, 2005

Low-Z Tracking Calorimetry

Magnetised Iron Spectrometers

Water Čerenkov

Liquid Argon TPC

Emulsion Cloud Chamber

Main issues in launching the Scoping Study on a -factory and super-beam facility

Some of the detectors also for astro-particle physics

To be carried out in parallel for detector optimisation

Physics requirements

Tests

Monte Carlo evaluation of detectors’ performance: signal and backgrounds

Detector R&D

Detector design

Comparisons and choices

”Where do we stand with (conceptual) beam-detector optimization for -beams and -factory beams?”

… was the main topic of the talk on

Neutrino detectors for future neutrino beamsby S. Ragazzi

More work to be done

Also emerged from WG reports and talks on specific detectors

One of the issues is ….

-factories: searching for wrong sign muons

More work to be done for detector optimisation↓

Tune Monte Carlo on the basis of existing detectorsAssume baseline design, in collaboration with engineers

Simulate detectorsDetector optimisation

Compare different detector concepts and designs …..………..

Background from:

- wrong charge assignment to leading muon: reduced with momentum cut and track fit cut

- from -decay or from heavy quark decay: reduced with isolation cut (e.g. require minimum pt of the leading muon with respect to hadron jet)

Momentum tracking threshold and resolution: affect sensitivity, degeneracy and possibility to lower E (talk by P. Huber)

This talk: Detector R&D: status and priorities

Some of the progress which has been done

Main issues on detector R&D and design

(in partial overlap with WG reports)

Low-Z Tracking Calorimetry

NOA in off-axis NuMI beam

Main issue: mass 10 x MINOS → new technologies to reduce cost

Observe 13

Liquid (plastic in MINOS) scintillator

Avalanche Photo Diodes (APD) (PMT’s in MINOS) higher QE → longer strips → less readout channels

Totally Active liquid scintillator Detector (TASD): now retained

No need of underground location (live-time ~100 s/year) Active shielding from cosmic rays foreseen (cheaper than passive overburden)

Detector to be completed in late 2011 if funding begins in late 2006

Main new technologies with respect to MINOS

The “totally active” NOA detector

30 kton mass: 24 kton liquid scintillator, 6 kton PVC

4-6 cm (x, y, z) segmentation

Progress in the mechanical design and in the construction methods: details are taking shape

Experience with trackers: potentially useful also for magnetised iron spectrometers

Magnetised Iron Spectrometers

A Large Magnetic Detector (LMD) for a Factory

• Iron calorimeter,plastic scintillator rods as active detector

• Magnetised at B = 1 T→ see “wrong sign” muons from e-

• Conventional technique, but 40 kton mass (one order of magnitude > MINOS)

• Only concept available: practical problems must be addressed to assess the feasibility (mechanics, magnet design, …. ); technical support needed

• More simulation work to be done to understand and optimise the performance

Making a torus bigger than MINOS

• From the talk by J. Nelson:

“the detector is feasible”– large area toroidal fields can by

extrapolated from MINOS design (thicker plates for large planes)

– can now make an affordable large area scintillator readout with NOvA technology

Engineering work must be done on mechanics, magnet design, ….

Studies required to optimise the performance of the detector (tracking threshold, resolution, background rejection, e-ident, …)

Make direct use of the experience with MINOS

A 50-100 kton magnetised iron detector à la Monolith

Monolith concept by P. Picchi and collaborators taken up for the

India-based Neutrino Observatory (INO)(talk by N.K. Mondal)

→ atmospheric neutrinos, in future -factories

Investigations started with Monolith to be taken up again:

detector performance studies, comparison horizontal vs vertical iron plates, design optimisation, comparison with other detectors,

…..

Comparison of Hyper-K and UNO .vs. Super-K

Super-K Hyper-K UNO

Total mass [kton] 50 2 x 500 650

Fiducial mass [kton] 22.5 2 x 270 440

Size 41 m x 39 m 2 x

43 m x 250 m

60 m x 60 m x 180 m

Photo-sensor coverage [%] 40 40 ⅓ 40 (5 MeV threshold)

⅔ 10 (10 MeV threshold)

PMT’s 11,146 (20”) 200,000 (20”) 56,650 (20”)

15,000 (8”)

A large fraction ( ½ or more) of the total detector costcomes from the photo-sensors

With present 20” PMT’s and 40% coverage for the full detector, the cost of a Mton detector could be prohibitive

IMB / KamiokaNDE → Super-K → Hyper-K / UNOIn each generation one order of magnitude increase in mass

Increasing the detector mass …

• better energy containment

• larger “effective” granularity of photo-sensors (due to larger average distance of photo-sensors from event vertex)

Main issue

R&D on photo-sensors, in collaboration with industries*to improve:

cost

production rate: affects construction time and may give serious storage problems

performance: time resolution (→ vertex), single photon sensitivity (→ ring reconstruction)

* The development of 20” PMTs was fundamental for KamiokaNDE and Super-KamiokaNDE

R&D on photo-sensors for Water Čerenkov

PMT’s Automatic glass manufacturing not the way to reduce cost and speed-up production rate:

required quantities still small compared to commercial PMT’s

Collaboration with industries (Hamamatsu, Photonis, …. )- very important for an effective R&D

- competition could stimulate ways for cost reduction

Are 20” PMT’s optimal? Global cost PMT+glass sphere , risk of implosion, …

What is the optimal photo-sensor coverage? Function of physics, energy, ..

New photo-sensors– Hybrid Photo-Detectors (HPD) by ICRR Tokyo - Hamamatsu

– …….

Long term stability and reliability are a mustProven for PMT’s

Simpler structure → lower costno dynodes

Single photon sensitivityfrom large gain at the first stage

Good timing resolution (~1ns)PMT-SK: ~2.3 ns (mainly TTS)

Wide dynamic range (>1000 p.e.)

determined by AD saturation

Challenging HV (~20 kV)→ focus onto a small AD (5mm)

Smaller Gainhighly reliable low-noise amplification and

readout needed

Principle of HPD and comparison to PMT’s

photocathode

avalanche diode(AD)

photon

Bombardment Gain

~4500@20kV

Total Gain

~105

Avalanche Gain

~30 or more

HVphoto electron

( p.e.)

PMT-SKdynodes

TTS (Transit Time Spread)

Total Gain

~107

HPD

R&D on HPD’s

•Proof of principle achieved with 5” prototype

•New results: 13” prototype tested with 12 kV: gain 3x104, single photon sensitivity, timing resolution 0.8 ns (2.3 ns with PMT’s), good gain and timing uniformity over photo-cathode area

•Next steps:- new bulb: 12kV → 20kV, giving wider effective photo-cathode area and higher

gain- higher gain from AD, low-noise preamp, readout

1st peak

2nd peak

0 p.e.30,000 electrons

1 p.e.

RMS 0.8 ns

An ancestor of hybrid PMT’s

• P.h. resolution: elimination of single p.e. noise (for DUMAND)

• Patented by Philips (Photonis)

• Copied by INR, Moscow: → the “QUASAR”

• Large investment by Philips/Photonis:

made ~ 30

• 200 QUASARs (15”) operating for many years in Lake Baikal

• No ongoing production

Photo-cathode

PMT

scintillator

photon

photo electron

25 kV

Liquid Argon Time Projection Chamber

Two target mass scales for future projects:

100 ton as near detector in Super-Beams (not discussed here)

50-100 kton for oscillation, astrophysics, proton decay

• Cryogenic insulation requires minimal surface/volume

→ A single very large cryogenic module with aspect ratio ~ 1:1

Do not pursue the ICARUS multi-module approach

• Longer drift length, to limit the number of readout channels

Two approaches:

1. 3 - 5 m drift length, with readout as in ICARUS

2. Very long drift length (~ 20 m) and “Double Phase” readout (amplification in Gas Argon to cope with signal attenuation)

In both cases, the signal attenuation imposes a high LAr purity (~ 0.1 ppb O2 equiv.)

ICARUS T300 module: 0.3 kton, 1.5 m drift, ~1 ms drift time“The present state of the art”

ICARUS: a ~ 2 kton detectorto be operated underground at Gran Sasso

To reach 50-100 kton mass

Double-Phase (Liquid – Gas) readoutBasic references: Dolgoshein et al. (1973); Cline, … Picchi ... et al. (2000)

Tested on the ICARUS 50 l chamber

Charge attenuation after very long drift in liquid compensated By charge amplification near anodes in gas phase

•With 2 ms e-lifetime,the charge attenuation in 10 ms is e-t/ ≈ 1/150(original signal 6000 e- /mm for a MIP in LAr)

•Amplification in proportional mode (x 100-1000)on thin wires (≈ 30 m) with pad readout or ..…

•Diffusion after 20 m drift → ≈ 3 mm : gives a limit to the practical readout granularity e-

Ampl. + readout

race track electrodes

Liquid Ar

Gas Ar

Extraction grid

A Liquid Ar TPC for the off-axis NuMI beamLetter of Intent, hep-ex/0408121 (2004)

•A detector for oscillation

•Readout as in ICARUS, with detector subdivided in readout sections

•15-50 kton : 0.5-1.5x102 extrapolation in mass from ICARUS T300

•3 m max drift length (1.5 m in ICARUS T300) with E = 0.5 KV/cm •Surface location foreseen (operated only with beam)

•Progress in the engineering design (talk by S. Pordes)

HV

S igna l

A 100 kton Liquid Argon TPC with “Double-Phase” readoutA. Rubbia, Proc. II Int. Workshop on Neutrinos in Venice, 2003

•A detector for oscillation, astrophysics, proton decay

•A single cryogenic and readout module

•20 m drift length, 10 ms drift time with as much as 1 KV/cm (0.5 in ICARUS T300):

•Liquid Ar at boiling temperature, as for transportation and storage of Liquefied Natural Gas

•~ 3x102 extrapolation in mass from ICARUS T300

Liq. Ar

Cathode (- 2 MV)

Extraction grid

Charge readout plane

Scint. (UV) and Č light readout by

PMTs

E ≈ 3 kV/cm

Electronics racks

Field shaping electrodes

E ≈

1 k

V/c

m

Gas Ar

p ≈ 3 atm

p < 0.1 atm

20 m

dri

ft

Electron drift under high pressure (p ~ 3 atm at the bottom of the tank)

Charge extraction, amplification and imaging devices

Cryostat design, in collaboration with industry

Logistics, infrastructure and safety issues (in part. for underground sites)

Tests with a 5 m column detector prototype

● 5 m long drift and double-phase readout ● Simulate 20 m drift by reduced E field and LAr purity

Study of LAr TPC prototypes in a magnetic field (for Factory): tracks seen and measured in 10 lt prototype

Ongoing studies and R&D(from A. Rubbia)

First operation of a 10 litre LAr TPC in a B-field(talk by A. Rubbia)

150 mm

150 mm

First real events in B-field (B=0.55T), New J. Phys. 7 (2005) 63

Tentative layout of a large magnetized Liquid Argon TPC(talk by A. Rubbia)

Liq Ar

Cathode (- HV)

Extraction grid

Charge readout plane

UV & Cerenkov light readout PMTsand field shaping electrodes

E≈ 1 kV/cm

E ≈ 3 kV/cm

Electronic racks

Gas Ar

B≈ 0.11 T

Magnet: solenoidal superconducting coilMagnet: solenoidal superconducting coil

Two phase He

LHe

LHe Cooling: Thermosiphon principle + thermal shield = LArLHe Cooling: Thermosiphon principle + thermal shield = LAr

Phase separator

Herefrigerator

The Emulsion Cloud Chamber (ECC) for e→ appearance at Factories

• e→ (golden events) and e→ (silver events) to resolve 13 - ambiguities

• Pb as passive material, emulsion as sub-m precision tracker:unique to observe production and decay

• Hybrid experiment: emulsion + electronic detectors

• 1.8 kton OPERA target mass→ ~ 4 kton at Factory

• Scan events with a “wrong sign” muon: x 2 increase of scanning power required

• OPERA is a milestone for the techniqueThe OPERA detector

(~200,000 bricks)

“Brick”(56 cells, 9 kg)

8 cm (10X0)

Basic “cell”

Pb 1 mmEmulsion

Summary (1): Low-Z Calorimetry

- eoscillations → 13 in off-axis NuMI beam: NOA

Evolution of a proven technique

Main issue:improve performance and reduce cost of trackers

NOA: mass ~ 10 x MINOS

New technologies with respect to MINOS plastic → liquid scintillator: a totally active detector now chosen

PMT → Avalanche Photo Diodes (APD)

Progress on trackers potentially useful also for magnetised iron sampling spectrometers or for calorimetry in view of other applications

(maintain contacts with the collider community)

Summary (2): Magnetised Fe Spectrometers

“Wrong sign” from e→ oscillations at -Factories Well proven technique Target mass ~ 10 x MINOS Proceed from concepts towards a design• Engineering work (mechanics, magnet design, …. ) must be done to

assess the feasibility; technical support needed

• Evaluate and optimise the performance of the detector (tracking threshold, resolution, background rejection, e-ident, …)

→ detailed detector simulations

Summary (3): Water Čerenkov

oscillation , astrophysics, proton decay

Proven and successful technique, well known also in its limitationsSuper-K: a large Water Čerenkov detector of which the performancehas been simulated and observed

Experience with experiments:K → Super-K → Hyper-K/UNO/Frejus: in each step mass x ~10

Main issue: cost and production of photo-sensors

→ collaboration with industries: very important, to be supported

→ are 20” PMT’s optimal? Which is the optimal photo-sensor coverage?

→ R&D on new photo-sensors with adequate long-term

stability&reliability

Summary (4) : Liquid Argon TPC

A beautiful detector for oscillation , astrophysics, proton decay.Broad energy range

Tested at the scale of the 0.3 kton ICARUS T300 module:extrapolation in mass by two orders of magnitudes or more needed

New features envisaged to reach 50-100 kton: longer or much longer drifts, double-phase amplification and readout

Experience accumulated for ICARUS, dedicated R&D (results now available from 10 liter chamber in magnetic field, …)

Substantial R&D required on various aspects, partly depending on the design parameters: signal propagation and readout, HV and electric field shaping; cryogenics, purification, operation in a magnetic field, civil engineering, safety and logistics, …..

Proceed from concepts towards detector designs (without and with magnetic field)

Location: underground (availability and cost, more severe safety issues) orsurface location (assess if adequate: loss of events superimposed to cosmics)

General conclusions

Very interesting times for the scoping study and for the future of neutrino physics

Work done by groups and collaborationsRequires support by the respective institutions

The scoping study will provide an important framework to exchange knowledge, device strategies and best collaborate

Establish interactions with R&D for other purposes, e.g. for linear collider physics

A lot of work is going on