icarusicarus.lngs.infn.it/serwer/conferences/scientific... · icarus liquid argon imaging tpc (i) o...

ICARUS A Status Report on

the LAr Detector Construction

Carlo RubbiaUniv. of Pavia and INFN

Carlo Rubbia, 4/9/00, SPSC 2000

Slide 2

Th

e IC

AR

US

Co

llab

ora

tion

Car

lo R

ubbi

a, 4

/9/0

0, S

PS

C 2

000

Slid

e 3

3 ton prototype

24 cm drift wires chamber

1991-1995: First demonstration of the LAr TPC on large masses. Argon recirculation in gas phase. Long duration test. Measurement of the TPC performances. TMG doping.

First purity monitor chamber

30 litres prototype

50 litres prototype1.4 m drift chamber

10 m3 industrial prototype

1994

1998-1999: Ultra-pure LAr technique industrialization.Forced LAr recirculation.

1997-1999: Neutrino beam eventsmeasurements. Readout electronicsoptimization. 1.4 m drift test.

The ICARUS Geneaology

1987: First LAr Ultra-purification.Measured Lifetime > 10 ms

1987: First LAr TPC. Proof of principle.Measurements of TPC performances.

1996: First LAr TPC built outside CERN.Scintillation light measurements.

Liquid Phase purification


Slide 4

Event Imaging in Liquid Argon

O Detect electrons produced by ionizing tracks crossing the LAr

v—

v+

+

—

Ionizing track

V

i0

E

d

d

d

p

Ionizing track

1st Induction wire / Screen grid

2nd Induction wire grid (x view)

Collection wire grid (y view)

e-

Ch

arg

e

Drift timeA

B

C

Signals induced

Ch

arg

e

Drift timeA B

C

Drift

Electron-ion pairs are produced

Electrons give the main contribution to

the induced current due to the much

larger mobility

I0 = e(v+ + v-)/d

A set of wires at the end of the drift give a sampling of the track

No charge multiplication occurs near the wires ➨ electrons can

be used to induce signals on subsequent wires planes with

different orientations ➨ ➨ 3D imaging


Slide 540 cm

40 c

mW

ires

Drift

The LAr TPCState of the Art Technology


Slide 6

ICARUS liquid argon imaging TPC (I)

O The LAr TPC technique is based on the fact that ionization electrons can driftover large distances (meters) in a volume of purified liquid Argon under a strongelectric field. If a proper readout system is realized (i.e. a set of fine pitch wiregrids) it is possible to realize a massive "electronic bubble chamber", with superb3-D imaging.

40 cm

40 c

mW

ires

Drift

"Bubble" size ≈ 3 x 3 x 0.2 mm3

Energy depositionmeasured for eachpoint


Slide 7

ICARUS liquid argon imaging TPC (II)

Detector is continuously sensitive, thus allowing to easilysimultaneously collect atmospheric, CNGS and other rare events...

Time -- drift

Rea

l eve

nt f

rom

15

ton


Slide 8

CERN ν-beam

νµ + n → µ − + p

128

read

out

wire

s2.

54 m

m w

ire p

itch

ICARUS-CERN-Milano

(Chamber located in front of NOMAD detector)

collection view time (400 ns/sample)46 cm max. drift distance

Neutrino event in 50 liter LAr TPC (1998)


Slide 9

ICARUS: a graded strategy

O The partnership of specialized industry already at the level of conceptual designhas been crucial to the development of larger detector masses.

Small-scaleprototypes Ò15 tonÓ 2 x Ò300 tonÓ Ò1400 tonÓ

➨ Air Liquide for Cryostat and Argon purification➨ BREME Tecnica for internal detector mechanics➨ CAEN for readout electronics

Cooperation with specialized industries:

Full test expected before end of 2000

?

≈2 m max. drift4 x 4 m2 cross

section


section


section


section

Lab activities:


Slide 10

T600:Rationale

O As clearly stated in the original proposal, the T600 has to be considered one morestep towards larger detector masses. Although it has a physics program of its own,(somehow limited by the mass, but still relevant to neutrino physics) the T600 has itsmain justification in solving technical issues associated with actual operation of a largemass LAr device in the LNGS Tunnel.

O Although the Collaboration is fully involved in the T600 assembly, the design of thefuture, larger scale detector is continuing. The solution for the LAr super-module hasconverged towards a monolithic detector module unit of about 1.4 kton imaging mass,built with the same technology of the T600 half module to be hopefully repeated up tofour times in Hall B of LNGS. (External muon spectrometer still pending: ICANOE)

Ü Therefore a T600 half-module can be considered a 1/2 scale prototype for the full detector

O Capabilities of both LAr detectors forÜ atmospheric neutrinoÜ LBL neutrinos andÜ proton decay

have already been reported in several papers, proposals and presentations andpositively evaluated by the physics community .


Slide 11

The ICARUS T600 module

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Number of independent containers = 2Single container Internal Dimensions: Length = 19.6 m , Width = 3.9 m , Height = 4.2 mTotal (cold) Internal Volume = 534 m Sensitive LAr mass = 476 ton

Number of wires chambers = 4Readout planes / chamber = 3 at 0° , ± 60° from horizontalMaximum drift = 1.5 mOperating field = 500 V / cmMaximum drift time ≈ 1 msWires pitch = 3 mmTotal number of channels = 58368

2 independent aluminum containerseach one transportable inside the GS Laboratory

External insulation layer (400 mm)

LN2 cooling circuit

Signal feedthroughs

HV feedthroughs

Under construction

3


Slide 12

T600 Project - Main approvals

Jun 199 5 Proposal for 2 x 300 ton semi-modules (T600)

Nov 29, 1996 Approval of INFN “Consiglio Direttivo” (CD) and first financing

of T600 (Cryogenics)

Jul 22, 1997 Approval and financing (6 GLit) of a Joint venture between

INFN and Air Liquide for the 2 Cryostats and LAr Purifiers:

➥ “then” predicted duration: 3 years ➜ ➜ July 2000

Jul 98 Adjudication of contract for detector’s Mechanics (Cinel)

Nov 1998 Adjudication of contract for the High Voltage & Racetracks

Mid 1998 Adjudication of contract for the readout electronics (CA EN)

Mar 200 0 Phototubes in LAr for the readout of scintillation light (EMI)


Slide 13

T600 Project - Italian Funding (Y2000 curr.)

Estimated (1995) construction cost of T600 26.5 MSfr (33.1 BLi t)

Spent so far 21.8 MSFr (27.25 BLit)Needed until operational in LNGS (included LAr) 3.9 MSFr (4 .9 BLit)Actual, projected cost of the T600 project 25.7 MSFr (32.1 BL i t)

In the 1995 estimate the following items were not included, but are accounted in thegiven actual cost:

•Neutrons shield and neutron background measurement 1.2 MSfr•Test programme with the 10 m3 prototype 0.9 MSFr•Scintillation light detection system 0.4 MSFr•8000 additional electronic channels 0.7 MSFr

Total, 1995 unscheduled costs 3.2 MSFr (4.0 BLi t)

Costs well wi thin 1995 estimates : we did more with l ess !Costs well wi thin 1995 estimates : we did more with l ess !


Slide 14

T600 Project - Timetable

Dec 1998 - Jun 1999 Operation of 10 m3 in Pavia: LAr purification and recirculationtests, cryogenic test of internal detector mechanics, generalcryogenics plants performance evaluation.

Sep 1999 Completed the site preparation in Pavia for the T600 cryostat.Nov 1999 Completion of the “clean room” and of the “assembly island”.Feb 2000 Operation of the 10 m3 at LNGS: data taking with a fully

functional imaging ( up to 4 m tracks), final electronics & DAQ programs,cryogenics and purification

Feb 2000 - Apr 200 0 Successful, extended test run with cosmic ray trigger at GranSasso.

Feb 29, 2000 Acceptance tests and delivery in Pavia of the cryostat by AirLiquide of the first half-module

Mar, 200 0 Beginning of assembly of the internal detector mechanics.Jul 2000 Completion of assembly and positioning of mechanical

frames for the first half-module; Begin wiring.Aug 4, 2000 Acceptance tests and delivery in Pavia of the cryostat by

AirLiquide of the second half-moduleSept 2000(exp) Begin installation of electronics on top of dewarDec 2000 (e x p) First cool-down with LAr of T600

≈ 4 month’s delay withrespect to 1997 plan

≈ 4 month’s delay withrespect to 1997 plan


Slide 15

Planning for the assembly of the first half-module - Status at the end of August 2000 -

M T W T F S SM T W T F S SM T W T F S SM T W T F S SM T W T F S SM T W T F S SM T W T F S SM T W T F S SM T W T F S S M T W T F S SM T W T F S SM T W T F S SM T W T F S SM T W T F S SM T W T F S SM T W T F S S

4 WEEKth2 WEEKnd 3 WEEKrd

MAYS

5 WEEKth 8 WEEKth6 WEEKth 7 WEEKth

JUNE9 WEEKth 12 WEEKth10 WEEKth 11 WEEKth

JULY13 WEEKth 16 WEEKth

S

14 WEEKth 15 WEEKth

AUGUST

ASSEMBLY FIRST 1/2 MODULE

ASSEMBLY SECOND THIRD 2ASSEMBLY FIRST PART OF INSULATION 9INSTALL AUX INSTRUMENTATION 3POSITION SECOND THIRD 4ASSEMBLY THIRD THIRD 5INSTALL AUX INSTRUMENTATION 6POSITION THIRD THIRD & FULL ALIGN 7 8DELIVERY SECOND 1/2 MODULE 16INSTALL CATHODE & RACE TRACKS 10INSTALL AUX INSTRUMENTATION 11 12ASSEMBLY SECOND PART OF INSULATION 17INSTALL WIRES 13CABLING & STRAIGHT JOINTS INSTALL 14 15INSTALL CRYO & PURIFICATION DEVICES 26INSTALL THIRD PART OF INSULATION 17WIRES TENSIONING AND TEST 20 21INSTALL RACE TRACKS 23 24TESTS 22DISCONNECT AND CLOSE 1/2 MODULE 27 28FINISH INSULATION ASSEMBLY 29INSTALL FEEDTHROUGHS 18 19INSTALL ELECTRONICS 25FINISH CRYO & PURIFICATION PLANT 30 31

ACTIVITY # # # 1 WEEKst

M T W T F S SM T W T F S SM T W T F S SM T W T F S S17 WEEKth 20 WEEKth

S

18 WEEKth 19 WEEKth

SEPTEMBERM T W T F S SM T W T F S SM T W T F S SM T W T F S S

21 WEEKth 24 WEEKth

S

22 WEEKth 23 WEEKth

OCTOBER

CompletedMovedCryogenics & PurificationInternal Detector Mechanics

ElectronicsAuxiliary InstrumentationWires PositioningTests

Color Scheme:


Slide 16

ICARUS 15 ton (10m3) prototype (1999-2000)

O A recent major step of the R&D

program has been the

construction and operation of a

10m3 prototype

¬ Test of the cryostat technology

Test of the “ variable-geometry ”

wire chamber

® Test of the liquid phase

purification system; purity level

exceeded 2ms electron lifetime

T15 installation @ Pavia


Slide 17

Cryostat

Cryo. pump

LN2 exchanger

Control


Slide 18

Viewport

Top view of T15 prototype

Signal flanges


Slide 19

Cryogenic circuit

GAr purifactioncircuit

LAr purif.circuit LN2 circuit

COOLING

Car

lo R

ubbi

a, 4

/9/0

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000

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e 20

Spring system

View of the ICARUS T15 internal detector

Spring movementsensor


Slide 21

Cooling 15 ton prototype March Ô99

6Confirmation of thefunctionality of the variablegeometry mechanics

100

1000

-50 0 5 0 100 150 200 250

Lifetime evolution

Life

time

(µs

)

Elapsed Time (hours)

Pump OFF

Pump ON

6The electrons lifetime, afterabout 4 days of recirculation, wasbetween 2 ms to 3 ms.

LAr purityTemperature / Spring movement


Slide 22

ICARUS T15 @ LNGS

O The second test phase of theT15 prototype has in additionprovided:

¬ Long-term test of the cryostat

technology

Test of trigger via scintillation

light

® Large scale test of final readout

electronics

T15 installation @ LNGS (Hall di Montaggio)

Ü First operation of a 15 ton LAr massas an actual “detector”


Slide 23

Purity Monitors

PhotomultipliersPads

Cathode

Two wire planes (induction + collection)928 wires/plane, all connected for readout

ICARUS 15 ton prototype - internal detectors


Slide 24

Inner detector upgrade

O Construction of cathode andfield shaping rings (race-tracks)

O Substitution of wire connectingboards

O Cable connection from wires tofeedthrough

O Installation of 2 arrays of pads

O Installation of 2 PMTs forscintillation light detection

O Installation of 3 Purity Monitors


Slide 25

Top View

Lateral View

Internal Volumes Layout

Imaging region (35 cm drift)

External trigger

cathode

wires


Slide 26

• Just after LAr filling: τ ~ 100µs, according to expectations based on residual leak

rates ( 10-5 mbar/s).• In a few days of LAr pump operation: τ > 2 ms

Slow τ degradation (GAr recirculation off)

Electron Lifetime Measurements


Slide 27

Tracks in 15 ton prototype

Drift

Wir

es

40 cm

76 c

m

Drift

Wir

es


Slide 28

Second half-module during the vacuum test in Pero


Slide 29

Vacuum curve

1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

1.00E+01

1.00E+02

1.00E+03

1.00E+04

0.01000 0.10000 1.00000 10.00000 100.00000

Pumping Time (hr )

Ab

solu

te

pre

ssu

re

(mb

ar)

Primary Vacuum (speed = 72 m 3/ h r )

Turbomolecular pumping (speed = 2000 lt/sec)

Vacuum Tests - Second half-module


Slide 30

Walls Displacement s

- 3 5

- 3 0

- 2 5

- 2 0

- 1 5

- 1 0

- 5

0

5

1 0

1 5

0.00E+00 2.00E+02 4.00E+02 6.00E+02 8.00E+02 1.00E+03 1.20E+03 1.40E+03 1.60E+03

Absolute Pressure (mbar)

Dis

pla

cem

en

t (m

m)

D1 (mm)D2 (mm)D3 (mm)D4 (mm)D5 (mm)D6 (mm)D7 (mm)D8 (mm)D9 (mm)


Slide 31

Status of the T600 Assembly

O After the delivery of the first half-module, at the end of February 2000, we started theassembly of the internal detector mechanics. The mechanical frame, holding the wiresand all the other detector components, has been positioned and aligned to within 0.2 mmover the full detector length (19 m).

O Such a high mechanical precision, coupled to the “variable geometry” concept allows forcompletely independent offline production of wires. Wiring is indeed proceeding at aconstant rate and is now at about 40 % of what is needed for the second half-module.The production of the wires for the first half-module was completed about 2 months ago.

O Wires positioning in the first half-module started in the second half of August and is nowgoing on very quickly (about 500 wires / hour). We expect to complete the wirespositioning for the two chambers of the first-half module around the middle of September.

O The central cathode, all the auxiliary instrumentation that goes behind the chambers andpart of the cables (for electronics and wires test) were installed before the positioning ofthe wires.


Slide 32

First half-module delivery in Pavia


Slide 33

Positioning the first half-module in the assembly hall


Slide 34

Second half-module positioned on the insulation in Pavia


Slide 35

Second half-module positioned on the insulation in Pavia


Slide 36

First half-module - View of the roof during the insulationassembly


Slide 37

First half-module - View of the roof during the insulationassembly


Slide 38


O Signal cabling will follow the positioning of the wires. Installation of race-tracks and HVdivider chain will complete the assembly of the internal detector at the beginning ofOctober.

O Installation of thermal insulation and cryogenic systems is proceeding in parallel with theinternal detector assembly. The second half-module was delivered at the beginning ofAugust. Construction time was about 4 months (exactly the time originally estimated tobuild up an half-module) and the vacuum test was perfectly successful (2 x 10-4 mbarwere reached after about 30 hours of pumping). This demonstrates that, after few delaysencountered during the realization of the first half-module, the industry is now masteringefficiently the cryostat technique. Innovation always requires some initial tuning.

O About 2/3 of the insulation is presently installed. Cryogenics and purification units for bothhalf-modules have been produced and tested. Transfer lines for LAr and LN2 are underconstruction. Completion of the installation of the cryogenics and purification plant isplanned for the end of October.

O In the second half of September some electronics units will be connected to the wires tostart a series of tests to optimize the electronics installation (ground connections, powersupply filtering, etc.). Apart a small fraction of the channels of the second half-module allthe electronics boards have been produced and most of them have already beenindividually tested and qualified in the Padova laboratory.


Slide 39

Cryostat

Assembly of the T600 internal detector (clean room)

Dirtyobserver

Cleanworkers


Slide 40

Mo

un

ting

the

first third

of th

em

ec

ha

nic

al fra

me


Slide 41

Mounting the second third of the mechanical frame


Slide 42

Inte

rna

l de

tec

tor m

ec

ha

nic

al fra

me

co

mp

lete

ly a

ssem

ble

d a

nd

po

sition

ed


Slide 43

T600 - Internal Detector - View of the cathode


Slide 44

T60

0 -

Inte

rna

l De

tec

tor V

iew

of th

ec

ath

od

e


Slide 45

Inte

rna

l de

tec

tor m

ec

ha

nic

al fra

me


Slide 46

Wires tensioning devices (springs)


Slide 47

5727 544543

Induction 1 [0 ÷ 2111]Induction 2 [0 ÷ 5727]Collection [0 ÷ 5727]

0

05727

1055

1056

2111

05183

T600 wire numbering


Slide 48

Wires preparation

Two wiring tables working in parallel


Slide 49

Wire

insta

llatio

n in

T60

0 in

tern

al

de

tec

tor


Slide 50

View of the wires of the first plane (no tension)

60¡ wire plane3 mm wire pitch


Slide 51

T60

0 -

Inte

rna

l De

tec

tor


Slide 52

Status of the T600 Assembly.

O Several instruments, most of them custom designed to work at LAr temperature in highpurity environment, have been built tested and installed:

Ü LAr Purity monitors

Ü High precision LAr level meters

Ü Position meters for the wires tensioning springs and for the container walls

Ü Temperature probes

O An important addition that is being implement already in the first half-module is thedetection of LAr scintillation light for triggering and T0 measurement. Among the severalpossible solutions we opted for the simplest one: bare photomultipliers immersed in theLAr with a wavelength shifter deposited on the glass window to shift the VUV (λ=128 nm)proper wavelength of LAr to visible light. Intense work has been done in the past fewmonths to implement this solution:

Ü Test and qualification of every single PMT at room and LAr temperature (8 inches EMI PMTswith special treated bialkali photocathode to work at cryogenic temperature).

Ü Choice of most efficient wavelength shifter (TPB = TetraPhenylButadiene), deposition method(spray), aging properties, pollution of LAr, etc.

Ü Design and qualification of divider chains working at LAr temperature.


Slide 53

PMT

Purity Monitor

Position Meter

Continuous Level Meter

PT1000

Planned Positioning of Instrumentation in the T600 (Right)

Discrete Level Meter

1 Thirdst3 Thirdrd 2 ThirdndOpen side

Top

Bottom

Left

Right


Slide 54

Position meter PMT

Purity Monitors

T600 internal detector - sensors

Car

lo R

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a, 4

/9/0

0, S

PS

C 2

000

Slid

e 55Position meter for the walls (detail)

Car

lo R

ubbi

a, 4

/9/0

0, S

PS

C 2

000

Slid

e 56

Purity monitor (top position)

Car

lo R

ubbi

a, 4

/9/0

0, S

PS

C 2

000

Slid

e 57

LAr level meters

Car

lo R

ubbi

a, 4

/9/0

0, S

PS

C 2

000

Slid

e 58

8 inches PMT coated with TPB

Car

lo R

ubbi

a, 4

/9/0

0, S

PS

C 2

000

Slid

e 59

Signal feedthroughs flange


Slide 60

O External & Internalplanes:Ü Approx. unipolar input signal

ÜWidth ≥ 3 µs

Ü Short RC(“quasi-current” mode) tominimized pile-up

O Middle Plane:Ü Bipolar signal

Ü Long RC(“quasi-charge” mode) to gettriangular signals

ext.plane

mid.plane

int.plane

RC=50µs

RC=1µs

RC=1µs

Input signals & pre-amp feedback RC


Slide 61

Electronics racks

Digital crate

Analog crate

Link cables


Slide 62

The ICARUS read-

out chain

CAEN-V789 board: 2 Daedalus VLSI * 16 inputchannels (local self-trigger & zero suppression) +memory buffers + data out on VME bus

CAEN-V791 board: 32 pre-amplifiers +4 multiplexers (8:1) + 4 FADCÕs (10 bits - 20 MHz)

Decoupling board:HV distributionand signal input

One rack fully testedand optimized with realon-line data from the 50liter LAr TPC


Slide 63

Analogue Boards (V791C & V791Q) features

• S/N ratio > 10 for m.i.p.

10 m3 single wire waveforms (500V/cm)

induction plane (V791C)

collection plane (V791Q)

FWHM ~ 5 µs


Slide 64

MUX8:1

ADC

CLK 40 MHz

RAM

CKSYNC

EXT.TRIGGERS

EVENTFIFO

VM

E IN

TE

RF

AC

E

V789BOARD

Daedalus chip as on-line zero suppressor and local trigger enabler Raw data (ext. trigger)

Reduced data

V791BOARD

8 ANALOG

CHANNELS

32C

urre

nt/C

harg

e P

ream

plifi

ers

DAEDALUSCHIPS2 • 16 ch

Daedalus feature:Varying rise-timefront-edge finder

LINK


Slide 65

T600 event size

O One chamber has:ÜInduction 1 wires: 1056 + 1056ÜInduction 2 wires: 5728ÜCollection wires: 5728

O Full drift event size:ÜInduction 1: 2112 x 4096 x 2B ≈ 17MBÜInduction 2: 5728 x 4096 x 2B ≈ 47 MBÜCollection: 5728 x 4096 x 2B ≈ 47 MB

ÜTotal 111 MB/chamber


Slide 66

GE / GE

f/en

del

ectr

on

ics

f/en

del

ectr

on

ics

CPU

f/en

del

ectr

on

ics

f/en

del

ectr

on

ics

CPU

24x

f/en

del

ectr

on

ics

f/en

del

ectr

on

ics

CPU

f/en

del

ectr

on

ics

f/en

del

ectr

on

ics

CPU

24x

FE / GE

FE / GE

PC builder, filter scan, monitor

200 GB disk


200 GB disk


200 GB disk


200 GB disk

GE / FE

PCs utilities

DAQ system layout (T600 semi-module readout)

1Gb/s

1Gb/s

1Gb/s100Mb/s

FE = Fast Ethernet

GE = Giga Ethernet


Slide 67


O All signal feed-through have been produced and tested both for electrical connection and

vacuum tightness.

O Complete installation of electronics racks will start at the beginning of October.

O Online and offline DAQ programs (event filtering algorithms, event display program, slow

control system, etc.) are being extensively tested on simulated data and on data coming

from the 10 m3 prototype. The control room, that contains only PCs, communications and

storage units, is going to be setup starting from the end of September.

O Startup procedures for the operation of the T600 (vacuum pumping) are expected to start

at the beginning of November.

Hopefully, the 18 m long track will be our Christmas gift.


Slide 68

Scaling to a larger module

O The ICARUS programme has always been aiming at a ≈5000 tonof LAr, as justified by physics reasons (rates, competitivity).

O Initially planned for HallC, now we are destined to HallB, smaller incross section, but longer.

O This implies a practical cross section of inner volume of 8 x 8 m2,about twice the present semi-module of T600.

O In previous papers, we have assumed initially to “pile-up” two T600modules to make up for the cross section

O We are now confident that a single, 8 x 8 m2 LAr container can berealised, with substantial advantages:ÜNo insensitive material (walls) inside the sensitive volume

Ü Substantially cheaper detectorÜHigher degree of safety

O “Scale-up” by a linear factor 2, the present semi-module of T600.


Slide 69

Scaling to a L x 2 module

O Double the drift distance: this implies:ÜHV from 70 kVolt to 140 KVolt, to be tested with T600

Ü twice the drift time, with correspondingly twice the purity,already currentlyachieved and to be tested with T600

O Twice the wire length and twice the wire pitch:Ü wire capacitance (C) is higher. Note S/N ≈ C ≈15/1 for m.i.p.: widen wire

spacing from 3 mm to 5÷ 6 mm pitch to keep the same C and hence S/N

O Sensitive volume covered by each wire is increased roughly byfactor 2 {length} x 2{drift} x 6/3{pitch} = 8.Ü the already available T600 electronics is sufficient for roughly 600 ton x 8 =

4800 ton LAr. The actual figure is somewhat larger, since less dead spaces

O T600 is almost entirely “recycled”, namely re-deployingÜ Purification system

Ü Electronics, read-out and HV

Ü The T600 dewar becomes LAr storage container


Slide 70

- RACE TRACKS AND CATHODE ARE BOTH PIPES WITH DIAMETER 34 x 0.8 mm

- INTERNAL DETECTOR TOTAL OWN WEIGHT = 45 ton

- N. OF HORIZONTAL WIRES = 2 x 2 x 1200 = 4800

- HORIZONTAL WIRES LENGTH = 2 x 8419.29 mm

- N. OF WIRES AT ± 60 deg @ 6 mm pitch = 2 x 2 x 2304 = 9216

- ± 60 deg WIRES LENGTH = 8424.695 mm

- MASS EFFICIENCY = 1238.9 / 1819.66 = 0.68

- TOTAL LAr MASS = 8.6 x 8.35 x 18.10 x 1.4 = 1819.66 ton

- LAr IMAGING MASS = 1238.9 ton

- IMAGING VOLUME = 229.85 x 3.85 = 884.94 m3

- DRIFT = 3.85 m

- WIRES CHAMBER SURFACE = 2 x 7.200 x 15.962 = 229.85 m2

MAIN CHARACTERISTICS: 18 m long Module


Slide 71

Toward the full scale module - Cryogenics

O A study have been made in order to define the basic operations and proceduresneeded to build a monolithic cryostat for the ICANOE module with squaredcross-section and internal dimensions ≈ 8.6 x 8.6 x 16.6 m3.

O Basic construction procedures:

Ü The intrinsic modularity of honeycomb panels allows for a pre-assembly of sub-structures in the workshop. Operations will be completed and the cryostat will beclosed in the underground lab.

Ü With the present design, the thickness of the panels is very similar to the one of thoseused for the T600 ➨➨ the fabrication technology will be practically the same as theone already tested for the T600

Ü With the proposed structure, the shear stresses on the honeycomb panels will belower than the one presently occurring for the T600

Ü The total weight of the cold vessel is estimated ≈ 72 ton.


Slide 72

Toward the full scale module - Cryogenics

O To reduce the cooling LN2 consumption rate to the level of T600, a new insulation andLN2 circulation scheme have been studied. The insulation is a double wall style vacuuminsulation with Nomex walls:

O Theoretical performance is ≈ 5 W / m2. Nomex panels provide the required mechanicalstrength to stand vacuum load and a sufficient thermal insulation in case of vacuumbreaking.

O One of the insulation walls of the T600 is being made with the above technique to directlytest the performance.

O A new scheme of LN2 with natural circulation is foreseen to further reduce theconsumption due to the cooling circuit (present solution for the T600 is with forcedcirculation).

80 mm

80 mm

40 mm

200

mm Nomex

Nomex

Vacuum with SuperInsulation

Spacers

Car

lo R

ubbi

a, 4

/9/0

0, S

PS

C 2

000

Slid

e 73

CRYOSTAT CROSS-SECTION

EVACUATED INSULATION PANELS

COLD VESSEL

NON EVACUATED INSULATION PANELS

SUPPORTS

INSULATING FOAM PANELS

Car

lo R

ubbi

a, 4

/9/0

0, S

PS

C 2

000

Slid

e 74Lateral walls assembly

Car

lo R

ubbi

a, 4

/9/0

0, S

PS

C 2

000

Slid

e 75Top part assembly and positioning

Car

lo R

ubbi

a, 4

/9/0

0, S

PS

C 2

000

Slid

e 76Insulation panels pre-assembly


Slide 77

Toward the full scale module - Internal Detector

O The design criteria of the mechanics of the Internal Detector are essentially unchanged

with respect to the ones of the T600:

Ü the structure is mechanically independent from the LAr container;

Ü a variable geometry concept is introduced to ensure transportation to the Hall

Ü assembly of the structure will be done in an outside laboratory (Pavia) to minimize the amount of

work to be done in the underground lab.

O In particular a solution has been studied which allows to reduce the dimensions of the 8 x

8 x 16 m3 structure (literally by folding it) to a size which is transportable inside the hall.

O In this way we minimize interference between the assembly of the cryostat and the one of

the internal detector mechanics and we make maximum use of the structures already

developed for the T600 assembly.

O Detailed design work is currently going on and we are evaluating this solution in all

details, in view of a full engineering report which will be presented only when the T600

will be operational in Pavia, hopefully early next year

Carlo R

ubbia, 4/9/00, SP

SC

2000

Slide 78

280280280280120120

320320 450450450450

808084408440

8080450450

450450

DRIFT DRIFT 3850

3850DRIFT DRIFT 3850

3850

76007600

95009500

95009500

81608160

CATHODECATHODE

3 WIRE PLANES AT 0

3 WIRE PLANES AT 0°° - 60

- 60°° - 120 - 120°°

3 WIRE PLANES AT 0

3 WIRE PLANES AT 0°° - 60

- 60°° - 120 - 120°°

RACE TRACKSRACE TRACKS

TENSIONING DEVICESTENSIONING DEVICES

Front ViewFront View

Carlo R

ubbia, 4/9/00, SP

SC

2000

Slide 79

1068.711068.71

5320.865320.86

5320.865320.86

5320.865320.86

1068.711068.71

450450

450450

1773.621773.62

1773.621773.62

1773.621773.62

1773.621773.62

1773.621773.62

1773.621773.62

1773.621773.62

1773.621773.62

1068.711068.71

1068.711068.71

1773.621773.62

18100181001900019000

WIRE CHAM

BER LENGTH = W

IRE CHAMBER LENGTH =

15962.5815962.58

WIRE CHAMBER HEIGHT =WIRE CHAMBER HEIGHT =72007200

95009500SIDE VIEWSIDE VIEW

STRUCTURE VIEWSTRUCTURE VIEW

CATHODE VIEWCATHODE VIEW

WIRE CHAM

BER VIEWW

IRE CHAMBER VIEW


Slide 804540

4260

4540

4260

WIRE CHAMBERS FOLDED FOR TRANSPORTATION

SEMI CATODO SEMI CATODO


Slide 81

16462.58 22002200

4600

21862

300

TRANSPORTATION STUDY


Slide 82

Conclusions

O Assembly of the T600 is quite advanced: within few months the internaldetector of the first half-module will be completed, an additional month isrequired to complete the installation of the external devices. Realistically,the first 20 m long tracks should be seen early next year.

O Given our past record with all previous prototypes, we are confident thatalso the T600 will come into operation smoothly.

O The T600, operated in the LNGS in the course of next year should allowan appropriate scaling up for the final module (a linear factor 2). The fullengineering report will be finalised after the successful operation of T600

O Following the recommendation of SPSC,the ICARUS technology, once itis scaled to the “right” size, will become a powerful tool in particlephysics, in particular in order to explore neutrino oscillations both fromcosmic rays and CNGS and proton decay.

O The previous, remarkable contributions of bubble chambers especially inthe domain of neutrino physics are a good justification of our effort.

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