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