liquid xenon photon detector feb. 2004 meg review meeting liquid xenon detector and related topics...

Liquid Xenon Photon Detector Feb. 2004 MEG Review Meeting

Liquid Xenon Detector and Related Topics

• CEX beam test at piE1 Oct-Dec/03

• Detector calibration

• Other related topics– PMT R&D

– Refrigerator

– Liquid phase purification

– Cryostat

Liquid Xenon Detector Group


CEX beam test at piE1


Elementary process

- (essentially) at rest captured on protons:

- p 0 n - p n

0

Photon spectrum

54.9 82.9 129MeV

M/2

M/2(1cos*)

M/2

*

E=55 MeV * =


Angular selection -p0n

0(28MeV/c) MeV

eV

• Requiring

FWHM = 1.3 MeV

• Requiring > 175o

FWHM = 0.3 MeV

170o

175o

0

54.9MeV 82.9MeV

1.3MeV for >170o

0.3MeV for >175o


Overview of the beam test

• 25/Sep Detector was moved to the area. evacuation

• 27/Sep- Beam tuning• 29/Sep pre-cooling• 2/Oct-5/Oct Liquefaction• 5/Oct-29/Oct Purification(gas phase)• 5/Oct- Electronics setup• 15/Oct 0 detected• 24/Oct empty target run• 1/Dec PMT amplifier study• 6/Dec Recovery• 7/Dec Cold xenon gas data for PMT

calibration

22/Sep

29/Sep

6/Oct

13/Oct

20/Oct

27/Oct

3/Nov

10/Nov

17/Nov

24/Nov

1/Dec

8/Dec

0 detected

Beam tuning

purification

pumping

Cooling/liquefaction

DAQ

~7weeks

Recovery Cold xenon gas data


• Beam line– Magic momentum (110MeV/c)– FSH52, 4mm carbon degrader (110

107MeV/c) in ASY51– 26mm carbon degrader in front of t

he target– S1 counter (40x40x5mm3) to defin

e the beam

• Area layout– The Electronics barrack placed in th

e area with concrete shielding around it.

– All controls and monitors done in the barrack.

– Liquid nitrogen supplied from a dewar located in the area.

E1 beam line

Proton beamTarget

ASY51


Setup

Carbon degrader

Lead Collimator at the beam line exit


Hydrogen Target

• Thanks to Dr. J. Zmeskal.

• Liquid H2 cooled with a GM-refrigerator

• Temperature control

• Target cell– 0.5mm t Al

– 40mm d x 100 L

– 125cc liquid hydrogen

• Kapton foil– entrance

– exit

cell


NaI detector

• For tagging at the opposite side of LP 8x8 NaI crystals– 40.6x6.3x6.3cm3

• Located 110cm from the target

• Signal processor and Trigger Box (QUAD module) to provide trigger signal

A

B

C

D

E

F

G

H

8 7 6 5 4 3 2 1

For trigger

For trigger

Base Line

Stabilizer

Attenuator

x10

x10

ADC

Trigger

Box

TDC

Crystal Array

HV

Trigger module

Differential input stage

Differentiator, Attenuator and base line stabilizer

Output stage


NaICalibration

High voltage value for each PMT is adjusted by using cosmic ray events.

Pedestal subtraction & Gain correction are done in the offline analysis.

Energy and Vertex reconstruction are performed by using corrected charge information next slides.

Cosmic ray events HV adjust & Gain Correction


NaIEnergy Estimation

Search for the NaI crystal with maximum charge

Charge sum in the surrounding NaI’s.

The Calibration parameter is determined by using 129MeV data. ( 37MeV/cosmic peak )

Raw Sum　　　

NaI with MaxQ

Reconstructed Energy

55MeV

83MeV

threshold

129MeV

• - p 0 n

0

(E = 55, 83MeV)

• - p n

(E = 129MeV)


NaIEnergy Resolution

• 55 MeV 7.0+/-0.13 %

• 83 MeV 6.5+/-0.14%

• 129 MeV 6.1+/-0.04%


NaIVertex Reconstruction

Search for the NaI with maximum charge

Fit the charge distribution of the raw or column (8 NaIs in each) that include NaI with maximum charge using a gaussian function.

4cm diam. collimator.

NaI with MaxQ

x 2.7cmy 1.6cm


- stopping distribution in the target must be considered in subtraction

Timing Counter• 2 layers of

– 5cm x 5cm x 1cm BC404– Hamamatsu R5505 at both ends– 3mm t Pb plate

• Time resolution can be estimated internally by TC1-TC2

5cm x 5cm x 1cm t

BC404

R5505

Viewed from the target

100mm

Lead collimator

TC

LPNaI S1

TCtLP - tTC

Pb

!


Timing Counterefficiency and resolution

• ~40% efficiency for 83MeV (> 1MeV deposit in the scinti.)

• 60 psec time resolution in sigma

55MeV

83MeV

129MeV

GEANT simulation

Ratio of events with > 1MeV deposit in the scintillator

(TC1-TC2)/2


Xenon Large Prototypeoperating condition

• Gain/QE calibration– LED and as usual

• PMT gain 106, 5x106

• Absorption length after 2 weeks purification abs > 140cm (90% C.L.)

(central value ~2.7m)

• Xenon extracted from the chamber is purified by passing through the getter.

• Purified xenon is returned to the chamber and liquefied again.

• Circulation speed 5-6cc/minute


QE Calibration

The peak position is well reproduced by this MC code.

• Gas xenon data had been used for calibration because the absorption can be ignored in gas. – W-values are equivalent in gas and liquid?

• Established purification scheme provided very pure xenon.– Possible to evaluate PMT QE’s using the event.


Data Acquisition

• Hardware setup– ADC 3 ranges for front-face PMTs

2 ranges for the others– TDC for all PMTs– PMT amplifier (x10)

• BINP• Lecce

• Software– Online MIDAS– Slow control (MSCB+LabView)

• Refrigerator control, Temp., Pressure Monitor

• Data set– Collimators in front of LP and NaI

( back to back)– Timing Counter (Pb+Scintillator) i

n front of NaI

Preamplifier Module

Av = 1

-In

+In

300

15050

CLC449

Av = +1

300

300

CLC44950

50

Av = -10

Discrete transistors

50

Av = +1

AD8001

32 Channels

8 units

Full-bandwidth Outs

Full-bandwidth Outs

Low range (x8 amplification)

Middle range

High range (20dB attenuation)


Trigger

• back-to-back data– NaI : sum signal of the central 4 crystals– LP: sum signal of

• 8 PMTs on the front face & 4 PMTs on the back face

• data with opening angle < 180o

– NaI : QUAD module

• Very low threshold trigger for LP– One or two hit(s) in any one of 8 clusters

• , LED, cosmic-ray, pedestal triggers for calibration

123

4

5

6


Beam Condition• p(-)=107MeV/c

– Almost maximum separation (8nsec) of arrival time to the target between and , and between and e.

• Beam intensity– Up to 2.6 MHz @ 1800A

• Electron contamination in the beam– Negligible in triggered events

targetx=12mm

y=12mm

e/

~8nsec

TOF separation


0 signal example

LP ADC

NaI

AD

C

LP 83 MeV

NaI 55 MeV

LP 55 MeV

NaI 83 MeV


Background Condition• Background events

– most probably caused by beam-related neutrons,

– Energy deposit up to 9-10MeV,

– Corresponding to 1.5x106 p.e./sec

• Beam on/off– PMT output for events changes, reduced to 70%

of normal values at full intensity beam rate (less reduction at lower intensity)

• Not due to bleeder current shortage but due to photocathode saturation because we observed the same effect even with lower PMT gain.

events/ beam off

events/ beam on

Thermal neutron in Xe

•Absorption length ~ 3 cm• Capture close to calorimeter walls• Multi γ, ΣE(γ) = 9.3 MeV

PMTs used in LP do not have Al strip


Analysis

Energy Resolution

Time Resolution

Response to Neutrons


Analysis Procedure

1. Start Counter• Selection of - beam

2. NaI Detector– Selecting 55MeV or 83MeV – For 129MeV no event selection applied on NaI

3. Xenon Large Prototype• Position reconstruction

• Weighted mean for x and y, and depth parameter• MINUIT fitting for 3D position finding

– Cut-base analysis– Linear-Fit analysis


Position Reconstruction• Position:Position:

MINUIT fitMINUIT fit on the on the PMT distributionPMT distribution in the in the

entrance faceentrance face;;

Energy vs depthEnergy vs depth (X,Y) coordinates (X,Y) coordinates

CollimatorCollimator


Nfpmt(0.5)• Another depth parameter: Nfpmt(0.5)

– Sort front-face PMTs in the order of the distance to the x-y weighted mean position.

– Sum up PMT output in that order.

– Stop summing when the sum exceeds the half of Qsum[Front].

Number of PMTs used in the SUM.

1.0

0.5

QPMT

NPMT

deep shallow Better resolution for

shallow events


Energy Resolution

Cut-base AnalysisLinear Fit Analysis


Energy Resolutioncut-base analysis

1. Remove pedestal events.

2. Select 0 events

3. Position selection in x-y, R<1.5cm

4. Reject shallow and too deep events

5. Rejection of z<0 events (resolution does not change effect of material)


Energy Resolution cut-base analysis

• Correction of the depth dependence (10% improvement of the resolution)– Linear function

•FWHM = 4.5 ± 0.3 (left:2.7 + right:1.8) % ( of the right part: 1.53%)


Linear Fit• A vector of parameters {pi} = E, , , z…

• A vector of observables {qj} = PMT charges

{qj} {pi}

All in a linearised way fast

Linearisation

Here are the formulas:

Generate a sample of MC events and find the best hyper-plane:

Minimize (analytically) the deviation between the linear approximation and the true pi values (ONCE AND FOR ALL)

ijjiji cqqwp )( 0


Energy resolution @55 MeVEnergy resolution @55 MeV

No selectionsNo selections >2.5 cm from the >2.5 cm from the wallwall

13.5k events13.5k events

FWHM = 7.4 %FWHM = 7.4 %9.4k events (69 %)9.4k events (69 %)

FWHM = 6.5 %FWHM = 6.5 %


Energy resolution @83 MeVEnergy resolution @83 MeV

No selectionsNo selections >2.5 cm from the >2.5 cm from the wallwall

FWHM = 6.9 %FWHM = 6.9 % FWHM = 6.9 %FWHM = 6.9 %

No effect (deeper No effect (deeper events)events)


MC predictions (MC predictions (absabs = 3 m) = 3 m)

55 MeV55 MeVFWHM 4.0 %FWHM 4.0 %

83 MeV83 MeVFWHM 3.8 %FWHM 3.8 %


LinearityLinearity

With the same set of coefficientsWith the same set of coefficients::

55 MeV55 MeV 83 MeV 4.4 MeV (Am/Be) 83 MeV 4.4 MeV (Am/Be)

EErecrec = 55.3 MeV = 55.3 MeVEErecrec = 83.7 MeV = 83.7 MeVEErecrec = 55.3 MeV = 55.3 MeV EErecrec = 4.2 MeV = 4.2 MeV


Possible improvements - IPossible improvements - I

• Q.E.Q.E. Green: MCGreen: MCRed: dataRed: data with with Q.E. in gasQ.E. in gas

Charge distribution for data Charge distribution for data is is not so symmetricnot so symmetric as it as it should be …should be …

Q.E. Q.E. could be could be measured measured individuallyindividually in the in the Pisa Pisa cryogenic test facilitycryogenic test facility..


The The quality of the linear fitquality of the linear fit depends depends

very stronglyvery strongly on the on the MC/data agreementMC/data agreement ! !

MC refinementsMC refinements

- light collection/transport algorithms;- light collection/transport algorithms;

- Fresnel and/or total reflection;- Fresnel and/or total reflection;

- LXe scintillation light spectrum, - LXe scintillation light spectrum, absabs …. ….

Possible improvements - IIPossible improvements - II


The best that one can do …The best that one can do …

• Assume that the MC is correct Assume that the MC is correct

- determine a determine a “Q.E. set”“Q.E. set” comparing the comparing the expected expected and measured chargeand measured charge PMT by PMT; PMT by PMT;

- apply apply position cutsposition cuts to select the signal in a to select the signal in a restricted region. restricted region.


And this is the result …And this is the result …

Best result:Best result:

4.7 % FWHM4.7 % FWHM with: with: R < 1.5 cmR < 1.5 cmD from wall > 2.5 cmD from wall > 2.5 cm

No cutsNo cuts R < 3cmR < 3cm R < 3cm && D > 2.5 cmR < 3cm && D > 2.5 cm

R < 1.5 cmR < 1.5 cm


Comparison between cut based (CB) and Comparison between cut based (CB) and linear fit (LF) analyseslinear fit (LF) analyses

( ) = QSUM > 25000( ) = QSUM > 25000

Step Number of Selection FWHM Cuts efficiencyevents (%) after step 2

55 MeV1 CB 82K (34K) 8.5 ± 0.31 LF 18106 6.9 ± 0.2

r < 1.5 cm2 CB 7160 (4223) 7.9 ± 0.9 1002 LF 2204 5.9 ± 0.3 100

Depth cut3 CB 3077 (2059) 4.9 ± 0.4 43 (48.8)3 LF 1235 4.8 ± 0.2 56

z<0 & depthcorrection

4 CB 2001 (1993) 4.5 ± 0.3 27.9 (47.2)4 LF 1235 4.8 ± 0.2 56


Depth Cut Dependence(cut-base analysis)

• Events near the wall can be used with a bit poorer resolution: So the overall efficiency should be much higher.

No selection using depth

Nfpmt(0.5)>4


Position Dependence of Resolution

4.3±1.0 4.8±0.4 4.6±0.7

4.5±0.6 4.5±0.3 4.5±0.6

4.1±0.9 5.0±0.5 5.0±1.6


Masking Effect• Some PMTs are masked to simulate the curved shape of the final

detector.

without masking

edge of front

edge of front top,bottom

edge of front,top, bottom, right, and left


Ongoing Analysis

• Energy Resolution for 83 and 129 MeV (including alpha and TERAS results).

• Other masking to simulate in case that we have only 600 PMTs.– 1/2 on back, top, and bottom planes.– 1/4 on left and right planes.


Time Resolution(very preliminary)


Time Resolution I(right – left)

• TDC correction for time-walk (no position correction)

• TL, TR by weighted average of Ti

• <T> = (TL-TR)/2

PMT

i

iii Ni

Q

ctT ,1 ,

/1

/

,

,

1

2,

1

2,,

,

RL

RL

N

iRiL

N

iRiLRiL

RL

TT

i=r.m.s. of Ti

cut on Qi> 5 peApplied cuts:

• r < 1cm (T40ps)

•52<S1TDC<53 ns, 70<RFTDC<76 ns

•Qsum>30000 ( E>50 MeV)

only 1000 events retained

= 86 ps

Analysis still going on …


Time Resolution II(Xe – TC)

• Time walk correction for TC.– 60 psec () resolution

• Need correction for xenon– Time walk– Position (depth)

= 113psec at 5x106 gain• Beam profile: 1.2cm in 4cm diam. cyl

inder– 59 psec contribution () to tTC-tXe

96 psec in sigma

• Need to improve z (depth) resolution for improving time resolution

• And more …

LPNaI S1

TCtLP - tTC


Response to Neutrons


Neutron in the Large Prototyperecent measurement

γ energy spectrum

ADC

ADC

Without moderator (paraffin)

With moderator

Peak at 9.3 MeV

The neutron source is Am/Be (2 KBq) + diffused thermal neutron background in the experimental hall ( (?) note TN022 )

It can be improved: test with source on the calorimeter back and thicker moderator

γ energy spectrum

12216 scmn


Trigger condition : S1 * NaI4 Gain:5e6, FSH52: 125

E(NaI)>100MeV, Qsum<20000

- + p + n data

Neutron delay ~ 30ns(120cm/0.14c)

No bias data for Xe

Require S1TDC, RFTDC data

n

Qsu

m


Possible Detector Calibration Methods


The motivations

a frequent and precise check of the calorimeter stabilityeven during the normal data acquisition

An energy resolution of

Causes for gain instabilities:

• Beam intensity variations• Variable background rates (photons and neutrons in the experimental hall)• Effects of the temperature T variation on the photocathode Q.E. and resistivity• Effects due to the capacitive coupling• Possible hysteresis phenomena as a function of T

4%E/E (FWHM) means:


Thermal neutron capturePossible source:

Pulsed neutron generator (commercialy produced)

Am/Be (~10 KBq)

• Continuous n spectrum

Moderator: ~10-20 cm of the polyethylene

γ shield:• 40% thermalized n•10% n captured in moderator~ 3 cm of the tungsten

• Neutron lines: 4.5 or 14 MeV (d-d or d-t reaction respectively) • Typical intensity is 106 n/s or 108 n/s• Typical pulse rate and pulse width 10Hz and 1μs •Price ~ 10000 $

Counts

0 10 MeV


Precise calibration rarely performed

• γ‘s from decay (E(γ) ~ 54.9 MeV):

use of a liquid hydrogen target

• Optional calorimeter calibration over range of γ energies:γ‘s from a tagged electron beam (small magnet + MWPC’s)

θ (d

egre

es)

E (MeV)


Calibrations to be frequently performed (A)

Thermal neutron in Xe• Absorption length ~ 3 cm• Capture close to calorimeter walls• Multi γ, Σ E(γ) = 9.3 MeV• Possible spill-out

Capture on Ni plate on calorimeter wall • Single γ emission highly probable 52.7%• E(γ) = 9.0 MeV (used in SK)

52.7% 25.6% 4.65% 1.28%

9.0 9.0 8.534 8.122 7.698 MeV

0


Calibration to be frequently performed (B)

Other possibility (less recommanded):

Isotope activation far from detector with neutron generator and energetic neutron sources

• E(γ) = 6.13 MeV• Decay constant τ = 7.2 s

Possible reaction: or

Nitrogen laser UV: emission line at ~ 300 nm; use of the optical fibre and a small diffusor

• Gain and relative QE measurements

is PMT independent?

• No neutron on calorimeter (apart from hall background)

)175(

)330(

nmQE

nmQE


PMT Responseat high rates


A Problem with “Old” PMTs found:Dependence of PMT outputs on beam intensity

UV

BLUE

Beam on

Beam on onoff

83MeV

55MeV


The phenomenon reproduced by LED light simulating crowding (50 KHz of 5 MeV pulses) due to beam background

6 minutes

Neutrons rate during normal runs

Ia 0.6 A, Ib 70 A

Start crowd. Stop


Beam on/Beam off

• PMT output for & LED– Compare and LED peak position between beam off and on.

0

0.5

1

1.5

2

2.5

3

0 50 100 150 200 250

ratioratio(LED)

Serial #

rati

o

s

ourc

esso

urc

es

LEDLED


Cryogenics test facility at Pisa

• PMT tested in Ar gas at several temperatures (30 -120°C)

• Test LED (blue) pulse usually at 10-50 Hz, 300 mV, 20 ns wide

• Crowding LED (blue) 300 mV, 10-40 KHz, 20 ns wide (Ia=1,10 A)

• Crowding turned on and then off after some time

• One “old” PMT (6041) tested and the phenomenon reproduced


OLD (6041) PMT at –105 °C tested in Pisa facility

6020 120 Time (s)

3010 50 Time (s)

I crowding= 0.8 A

= 66 sec


PMT Test @ Univ. of Tokyo

PMT

PMT

Alpha source(241Am )

LED

Liq. Xe

5.5MeV alpha peak

PMT (Al Strip Type)

TB0094 TB0102 TB0286 TB0302

(now being analized…)

TB0284 TB0568


New PMT (9288)

• The prototype uses only “old” PMTs(6041).– New PMTs expected to behave better…

• Tests using new PMTs at low temperature are ongoing both in Pisa and Tokyo.

• Results will be reported at the review meeting.


Crowding considerations in the LP + final detector

• From the measured thermal neutron rate in the exp. Hall (TN022) one can estimate I 0.5 A in the LP and 5-6 times bigger in the final detector

• If this current has to be lower than 1% of the base current (70 A) we have to screen the final detector from thermal neutrons

• The corresponding current from low energy photons from the muon radiative decy turns out to be lower than for neutrons: I 04 A in the final detector Taken from the photonis PMTs handbook


Pulse Tube Refrigerator

1. Heat load and PT cryocooler 2. Further test and schedule


- Heat Load -

Heat LoadW@165K

Phase LXe(L)

PMT

Static PMT Cable

Total(W)

L.Proto 120 250 24 16 10 50Final 800 1000 20 65 45 130

-Based on the KEK-original PT cryocooler, Cryocooler with higher cooling power has been developed for the final calorimeter


Technology transfered to

Iwatani Co., Ltd

Designed:

150 W @165K

Large Power Pulse Tube Cryocooler



One for Columbia University

For Dark Matter SearchDesigned:

90 W@165K

3kWcompressor



Technology transfered to

Iwatani Co., Ltd.

Two for MEG

Designed:

150 W @165K

using 6.7kW compressor


Large Power PT Cryocooler-Cooling power at 6.7kW compressor-

PT150 Cooling Power

0

50

100

150

200

250

60 80 100 120 140 160 180 200

Temperature (K)

Cool

ing

Pow

er (

W)

Q150 (W)

Qkek(W)

KEK originalfor Large Proto

For final calorimeter6.7kW, 4Hz


Results and Further Tests

-Achieved cooling power of 190W at 165K (6.7kW compressor)

-Orientation dependence test... Horizontal layout for the case of two cold head-Another phase shift configuration (Double Inlet) test... To increase cooling power

Schedule

-January 2004: Final parameter fixed-February 2004: Fabrication will start-March 2004: Will be delivered (two sets)-Can be installed for the LXe liquid purification test


Liquid Phase Purification


Liquid phase purification test

• Pump and purifier in the Large Prototype chamber– Very simple

– No worry about heat load


Implementation in the final detector

• Xenon from the bottom bypass the wall to the pump/purifier

• Easy maintenance

• Possible heat load to the bottom

Next slide


Realization of the system

• Verification of liquid phase purification– Large Prototype is the

best to show the purification performance

• Long term operation in the final detector– Heat load to the bottom

must be minimized


Purification systemin the final detector

LXe CalorimeterLiquid circulating purifier

Liquid pump (100L/h)

Purifier1000L storage dewar

Cryocooler (100W)

LN2

LN2

Getter+Oxysorb

GXe pump (10-50L/min)

GXe storage tank

Cryocooler (150W)

Heat exchanger

Gas phase purification

Liquid Phase purification


Status• Fluid pump was delivered to a Japanese manufacturer.

• Assembling the pump and purifier cartridge for verification.

• The system will be tested using the LP.

motor

Outside of the cryostat

(room temp.)

Inside of the cryostat

(low temp.)

Impeller

Pump isolator


Cryostat Construction


Design goals:

-Design goals:-Independent test of the inner vessel and outer vessel during construction.-Implementation of a draining system.-A simplification of the supporting system (three legs.) and a limiting displacement system-Adding a pre-cooling system on the inner vessel covers.-Adding a safety valve on the outer vessel for positive pressure.-Adding a rohacell sheet between the outer thin window and the magnet structure for positive pressure.


-Problem with high strength austenitic stainless steel.-To obtain high yield we need a stress hardening process that causes a slight ferromagnetic characteristic that can be removed by a special heat treatment.-Size of the sheet can be another problem.-The austenitic ss with the nitrogen should have a better strength and a better magnetic characteristic.

Windows material


Thickness of the Walls/Covers

• Suppose the pressure tolerance of 0.3MPa for the inner vessel and 0.1MPa for the outer vessel (vacuum insulation layer).

Walls/Cover Material DimensionPressureDirection

Design PressureMPa

Design Tempdegree C

ThicknessCalculation (mm)

Thickness Actual(mm)

Inner Vessel Inner Wall SUS316L R623 x L1086 Outer 0.3 -108~40 5.4 7.0Inner Vessel Outer Wall SUS316L R1116 x L1086 Inner 0.3 -108~40 3.0 7.0

Inner Vessel Front Wall SUS316L min504 x max1086 Inner 0.3 -108~40 23.0 24.0Inner Vessel Cover SUS316L R1148 x R588 Inner 0.3 -108~40 22.7 24.0

Outer Vessel Inner Wall SUS316L R550 x L1260 Inner 0.1 40.0 0.5 0.5Outer Vessel Outer Wall SUS316L R1200 x L1270 Outer 0.1 40.0 7.5 8.0Outer Vessel Front Wall SUS316L min650 x max1270 Outer 0.1 40.0 16.7 20.0Outer Vessel Cover SUS316L R1200 x R540 Outer 0.1 40.0 15.4 20.0


Heat Load Calculation

• See also T. Haruyama’s talk on Jul 2002 review meeting.

• Main contribution is from PMT and cables.

• One pulse tube refrigerator can compensate the load.

• Possibility of mounting two refrigerator is now investigated

Heat load calcluation for the xenon photon detector vessel

UnitRadiation Outer Vessel -> Inner Vessel (30 Mylar layers) 3.1 WConduction Nozzle (N1-N3) via xenon gas 0.2 WConduction Nozzle (N1-N3) via belows 4.6 WConduction Support (brace and supporting pipe) 6.3 WHeat generation PMT (65mW/PMT) 52 WConduction PMT HV and Signal Cables 50 Wtotal 116.2 W


Several modifications from the previous design


Photon Detector

2002 2003 2004 2005

Test MilestoneAssemblyDesign Manufactoring

Large Prototype Beam Test Beam Test

Vessel Design Assembly & Test

PMT Delivery + Testing

Refrigerator Manufactoring Assembly

Liq. Purification

Assembly Test

Manufactoring

Engineering runs


Summary

• CEX beam test was carried out at E1 area.– Energy Resolution– Time Resolution

• PMT response at high rates is investigated.• Possible Calibration Method in consideration.• Liquid Phase Purification test will be done in 2004.• Refrigerator will be assembled and delivered soon.• Cryostat design renewal.• Plan in 2004

– LP operation in E5 to see background condition and COBRA magnetic field effect.

liquid xenon photon detector feb. 2004 meg review meeting liquid xenon detector and related topics...

Documents

liquid xenon photon

liquid h2

liquid nitrogen

meg review meeting overview

o slide

beam line exit slide

dec03 detector calibration

pie1 slide