# Presentation: 213722

## LArTPC: Large Liquid Argon TPC for the NuMI Off-axis Beam

- Context:
- Neutrinos and Fermilab etc
- Status Report on LArTPC Activities

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## Synopsis

-  This talk presents some of the efforts of the LArTPC group which is pushing the development of large liquid argon TPCs.  Our small group is currently composed of 6 University groups and 6 Fermilab staff physicists, and the number of people is growing.
-  Large neutrino detectors, including large liquid argon TPCs, clearly are needed for upcoming neutrino experiments and into the neutrino factory era.

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## ICARUS

-  The LArTPC group recognizes that the technical concept and any possibility that such a detector may be feasible owes a huge debt to the work done by the ICARUS collaboration.

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## The Big Picture 

- detector mass x
- detector efficiency x
- protons on target/yr x
- # of years

- The Big Picture

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## The promise of liquid argon

******0**
- Multiple secondary tracks pointing back to the same primary vertex
- Each track is two electrons
-  – 2 mip scale per hit

**Electrons**
- Single track (mip scale)
- starting from a single vertex

- Dot indicates hit, color is collected charge
- green=1 mip, red=2 mips (or more)

- use both topology and dE/dx to identify interactions

- cm

- cm

- cm

- cm

- X
- plane

- zoom
- in

- X
- plane

- zoom
- in

- U
- plane

- zoom
- in

- U
- plane

- zoom
- in

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## The promise of liquid argon

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

**Notes:**
for 0.5cm sampling and a 14cm radiation length, 3.5% sampling is 0.5/14

For NOvA, the sampling rate is every .15 of a radiation length or 15%

## * Head of Particle Physics Division at Fermilab

- From Presentation by Jim Strait* to Fermilab PAC June 20, 2005

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## P. Oddone September 12, 2005

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## P. Oddone September 12, 2005

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## P. Oddone September 12, 2005

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## P. Oddone September 12, 2005

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## P. Oddone September 12, 2005

- A Large Liquid Argon TPC for the NuMI Off-axis Beam is part of a plan at Fermilab

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## LArTPC’s report to NuSAG*

- Fermilab Note: **FN-0776-E**
- A Large Liquid Argon Time Projection Chamber for Long-baseline, Off-Axis
- Neutrino Oscillation Physics with the NuMI Beam
- Submission to NuSAG
- September 15, 2005
- D. Finley, D. Jensen, H. Jostlein, A. Marchionni, S. Pordes, P. A. Rapidis
*Fermi National Accelerator Laboratory, Batavia, Illinois*
- C. Bromberg
*Michigan State University*
- C. Lu, K. T. McDonald
*Princeton University*
- H. Gallagher, A. Mann, J. Schneps
*Tufts University*
- D. Cline, F. Sergiampietri, H. Wang
*University of California at Los Angeles*
- A. Curioni, B. T. Fleming
*Yale University*
- S. Menary
*York University*
-  Contact Persons: B. T. Fleming and P. A. Rapidis

- * The ***N***e***u***trino ***S***cientific ***A***ssessment ***G***roup for the DOE/NSF

- Soon to be on the hep-ex preprint server

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## NuMI Liquid Argon TPC Overview 

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## NuMI Liquid Argon TPC Overview 

- Note: At this point in time ...
- “15” could be “50”
- “1” could be “3”
- etc

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## The Large Liquid Argon TPC

-     Basic concept follows ICARUS:
- 	TPC, drift ionization electrons to 3 sets of wires (2 induction, 1 collection)
- 	record signals on all wires with continuous waveform digitizing electronics
- Differences aimed at making a multi-kton detector feasible**;**
**  ****	**Construction of detector tank using industrial LNG tank as basic structure
-   	Long(er) signal wires
- 	Single device (not modular)
- Basic parameters:
-  	Drift distance - 3 meters;  Drift field - 500 V/cm (gives vdrift = 1.5 m/ms)
-  	Wire planes - 3 (+/-300 and vertical); wire spacing 5 mm; plane spacing 5 mm
-  	Number of signal channels ~ 100,000 (15kt), 220,000 (50kt)
-     LRadiation = 14 cm,  dE/dx = 2.1 MeV/cm, 55,000 electrons/cm liberated

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## The Large Liquid Argon TPC

- Argon: (long drift)
-     purification - starting from atmosphere (cannot evacuate detector tank)
-                        - effect of tank walls & non-clean-room assembly process
- Wire-planes:
-     long wires - mechanical robustness, tensioning, assembly, breakage/failure
- Signal processing:
-       electronics - noise due to long wire and connection cables (large capacitance)
-       surface detector - data-rates,
- 		       - automated cosmic ray rejection
-            	                    - automated event recognition and reconstruction
- (and there are others  for example, High Voltage)

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

- Many large LNG tanks in service. excellent safety record

- Detector Tank based on Industrial Liquefied Natural Gas (LNG) storage tanks

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## The Large Liquid Argon TPC: Sketch

- 3D `Model’ cutaway
- 15 kt detector

- H
- V

- S
-  i
- g
- n
- a
-  l

-  Changes from standard LNG tank:
-  inner tank wall thickness increased - LAr is 2 x density of LNG;
-  trusses in inner tank to take load
-  of the wires:
-  penetrations for signals from inner
-  tank to floor supported from roof
-  of outer tank;

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## The Large Liquid Argon TPC: Beam’s Eye View

- Beam’s eye view
- showing the electrodes
- (cathode, field-cage
- and wires)

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## The Large Liquid Argon TPC: Site Features

- Site Layout (very) Schematic –
- showing some of the services needed

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## On the way to the Large Liquid Argon TPC

- Note: At this point in time ...
- “15” could be “50”
- “1” could be “3”
- etc

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## The Purposes of the “1 kton” tank

- Engineering Development to demonstrate scalability to large tank
- Construction of tank with the same techniques to be used with the large tank
- Demonstrate argon purity with the same techniques to be used with the large tank
- Mechanical integrity of TPC
- Readout signal / noise
- Microphonics due to argon flow
- Uncover whatever surprises there may be

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## The Purposes of the “130 ton” detector(50 ton fiducial)

- Physics development using existing technology
- Record complete neutrino interactions ( and e) in a high intensity beam
- Establish physics collaboration by:
- Developing event identification
- Developing reconstruction
- Developing analysis
- Establish successful technology transfer

- What Energy to pick?

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## NuMI Off-axis Neutrino Energy

- From the NOvA Proposal March 15, 2005

- The event spectrum in the 14 mrad off-axis beam peaks at about 2 GeV, and there are more events than at 0 mrad.

- CC ******** event rate for:
- - NuMI “medium” energy beam
-  No-oscillation hypothesis
-  800 km from Fermilab for various off-axis angles

- Pick 2 GeV.  Where can we get 2 GeV today?

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## NuMI Beamline and Surface Building

- From the NOvA Proposal March 15, 2005

- The 130 ton LArTPC detector would go in or near the MINOS Surface Building.

- The NuMI decay pipe is 675 m long

- The MINOS Near Detector Hall is ~ 105 meters BELOW the Surface Building

- hadron absorber

- Top View

- Side View

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## Electron Neutrinos in MINOS Surface Building

- NuMI is presently providing ~2E20 POT per year.
- The 130 ton LArTPC has a 50 ton fiducial mass.
- Thus ... the LArTPC detector would get ~1600 ****e events / year.

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## Muon Neutrinos in MINOS Surface Building

- Same assumptions as previous slide, except this shows ~15,000 muon neutrinos.
- The **** peak at ~2.8 GeV is from Kaon decay.

- From the NOvA Proposal March 15, 2005

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## NuMI Liquid Argon TPC: Getting Started

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## Materials Tests 

- Test Samples
- Dewar

- Filter

- ICARUS
- purity monitor

- System at Fermilab for testing filter materials and the
-  contaminating effects of detector materials (e.g. tank-walls, cables)

- G. Carugno et al.,
- NIM. A292 (1990

- Materials Tests

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## Materials Tests 

- Materials Tests

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## LArTPC Test Setup at Yale

- Purity and light collection

- Purity monitor in liquid argon

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## 5 m Drift Demonstration at Fermilab

- Cryostat drawing for purchasing department

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## Long Wires Tests

-  Induction (2 +/- 30) and Collection Planes spaced by 5 mm
-  5mm pitch within planes
-  ~220,000 signal wires total (50 kTon), ~100,000 signal wires (15 kTon)
-  Longest wire ~35 meters (50 kTon) , ~ 23 meters (15 kTon)
-   Need to be robust - no breakages
-   Need practical assembly and installation procedure.
-  Wire Material 150 micron Stainless
-  Present Concept: (different from ICARUS)
- Tension implemented by attaching a weight to each wire (~1kg) to avoid tension changes due to temperature changes.

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## Key Hardware Issues

- Technology transfer
-  Begin Technical Setups at Fermilab
-  Seeing tracks and light production at Yale
- Understanding long drifts (~5 m)
- Purity tests setups at Fermilab
-  Introduction of impurities, test of detector and tank materials
-  Test of filtering materials, demonstrate purification rate
- Very long wire electrode assembly/stability and readout
- Design for detector to be assembled with industrial techniques

- R&D path shaped by open questions for large detectors
- (part 1):

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## Key software issues

- Simulation Monte Carlo(s)
- Reconstruction / automated event reconstruction
- Physics analysis
- Key collaboration and physics issues
- Developing defensible cost and schedule
- Growing a strong collaboration
- Navigating a global, developing, exciting neutrino physics program

- R&D path shaped by open questions for large detectors
- (part 2):

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## Final Slide

- Growing support from University groups in smaller technical setups, software efforts, etc
- Receiving generous support for technology transfer from experts in Europe, and hoping to learn more from ongoing tests
- Hoping for continued interest from the US Government for neutrino physics in general and LArTPCs in particular
- Continuing along the path to develop Large Liquid Argon TPCs
- - not only in the ongoing NuMI era, but also into the neutrino factory era, and for other physics
- Would like to develop our efforts with wider participation

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## Back- ups, extras

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## Slide 39

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## Large Liquid Argon TPC for the NuMI Off-axis Beam 

- Large Liquid Argon TPC for the NuMI Off-axis Beam

- everything about drifting in one fine slide

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## towards a Large Liquid Argon TPC for the NuMI Off-axis Beam 

- ICARUS achieved 10 ms in 1997
- T600 lifetime evolution implies
- >10 ms asymptotic value

-  `purity’/lifetime requirements for <20% signal loss
-        3m   drift -> 10 ms lifetime = 30 ppt
-        2m 	drift -> 6 ms  lifetime  = 50 ppt
-        1m 	drift -> 3ms   lifetime  =  90 ppt

- Liquid Argon `purity’ requirements

- towards a Large Liquid Argon TPC for the NuMI Off-axis Beam

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## towards a Large Liquid Argon TPC for the NuMI Off-axis Beam 

-    ICARUS scheme - an intelligent waveform recorder on each wire:
-    Amplifier sensitivity achieved in existing custom devices for this capacitance
-    (S/N) =22,000 e / 2500 e = 8.5/1
-     - digitize with commercial ADCs adequate performance, reasonable cost
-    -  intelligence from commercial FPGAs adequate performance, reasonable
-       cost.
- Data Acquisition
-   Use commercial switches and multiplexors
-   Have a design to achieve 5 Gbyte/second into 200 PC’s for reasonable cost.

- Electronics and Data Acquisition Summary

- towards a Large Liquid Argon TPC for the NuMI Off-axis Beam

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

##  Raw data rate = nwires  x  2.5 MHz; need 2 bytes per sample

** ****WFT (****Wave Form Train****)  is all the digitizings **
- `Zero’ suppression:  *Cosmic ray rate  is 200 kHz; each ray ~5000 signals,*
-  Set intelligent threshold in FPGA,  pass next 40 samples
** ****DAT (****Data Above Threshold) **
-  Processing each hit fully in FPGA to return pulse-height and time;
-  requires 4 bytes/hit
** ****FHP (Full Hit Processing) **

- Data Acquisition schematic

- towards a Large Liquid Argon TPC for the NuMI Off-axis Beam

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## * Spill Only looks at 4 milliseconds (to see events plus any early cosmic rays) each spill (every 2 seconds)

| Data Type &
Data Rates | Spill Only*
 (bytes/sec) | Always Live
  (bytes/sec) |
| --- | --- | --- |
| Wave Train | 2 x 109  | 1012  |
| Data above  threshold  | 8 x 107  | 4 x 1010  |
| Full hit processing  | 8 x 106 | 4 x 109 |

- towards a Large Liquid Argon TPC for the NuMI Off-axis Beam

- 50 kt data rates

- exceeds bandwidth
- of 5 GB/sec

- Note: Full hit processing allows for Always Live running

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## Simulation Results

- LArTPC
-   Total absorption calorimeter
-   5mm sampling  -> 28 samples/rad length
-   Excellent energy resolution
- First pass studies using hit level MC show 81 ± 7 %   efficiency and
- Neutral Current rejection factor ~70
- (only need NC rejection factor of 20 to reduce NC background down
-   to 1⁄2 the intrinsic  rate)

- high e efficiency
- good NC rejection

- Large Liquid Argon TPC for the NuMI Off-axis Beam

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## NC

- Training samples:
- 50 events each of eCC, CC and NC
- individual samples to train
- mixed samples to test training
- Blind scan of 450 events
- scored from 1-5 with
- signal=5
- background=1

-    Neutrino event generator: NEUGEN3, used by MINOS/NOvA collaboration (and others)
-    Hugh Gallagher (Tufts) is the principal author.
-    GEANT 3 detector simulation (Hatcher, Para): trace resulting particles through a homogeneous volume of liquid argon. Store energy deposits in thin slices.

- Analysis was based on a blind scan of 450 events, carried out by 4 undergraduates with additional scanning of “signal” events by experts.

- open region:
- students
- hatched
- region:
- + experts

- Tufts University Group

- CC

- eCC

- log scale

- Large Liquid Argon TPC for the NuMI Off-axis Beam

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

**Notes:**
One of the best ways to develop an automated reconstruction package is to start with a hand scanning exercise to best understand event topologies.  

This study is a first step towards that effort

scanning done on events like I have already shown you

- Signal e

- Overall efficiencies, rejection factors,
- 						and  dependencies

- Efficiency is ~100% for  y<0.5, and  ~50% above this

- Efficiency is substantial even for high multiplicity (DIS) events

- signal e

- eff.

- y=Ehad/E

- Large Liquid Argon TPC for the NuMI Off-axis Beam

- Event type

- Overall efficiency 81% +/- 7%
- Rejection of NC is 73 (+60,-30)

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam

## LArTPC work underway

- Bartoszek Engineering

- Work funded by
- DOE Advanced Detector
- Research Grant

- at Yale
- How good are these detectors at IDing low (~1 GeV) energy  interactions?

- understand the technology
- purity studies
- understand detector response at very low energies
- study combination of charge and light production for particle ID

- Constructing small prototype
- vessel this summer

- David Finley, Fermilab / Sept. 22, 2005 to ISS @ CERN/ A Large Liqud Argon TPC for the NuMI Off-axis Beam