# Presentation: 227608

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

- Brief description of  some of the efforts of the LArTPC group which is pushing the development of large liquid argon TPC’s aimed at upcoming neutrino experiments as well as experiments in a neutrino factory era.
- Greg Bock
- FNAL/BNL Meeting
- November 14, 2005
- (Almost entirely a selection of slides from Dave Finley’s presentation to the ISS)

## The promise of liquid argon

- 
- 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
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- zoom
- in

- U
- plane

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- U
- plane

- zoom
- in

## 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

## 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

## NuMI Liquid Argon TPC Overview 

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

## 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)

- Many large LNG tanks in service. excellent safety record

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

## 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;
- Tank diameter ~ 26meters

## Development tasks

- 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
- 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

## 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.

## Materials Tests 

- Materials Tests

## LArTPC Test Setup at Yale

- Purity and light collection

- Purity monitor in liquid argon

## Final Comments 

- Receiving  support for technology transfer from experts in Europe, and hoping to learn more from ongoing tests
- 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
- The group would  like to develop wider collaboration. Most Fermilab people are also starting to think about what can be learned with the INFN groups. A workshop in Italy in February or March seems like it will happen and it could help establish a way to begin to sort out who does what. Figuring out what makes sense on coordinating with US labs has only just now begun.

- Final Comments