RAP-Rivelazione Acustica di Particelle

Present Status and First Results

RAP Collaboration

Lina Quintieri, 23 Settembre 2004SIF 2004-Brescia

S. Bertolucci, E. Coccia, S. D'Antonio, A.C. Fauth, A. de Waard,G. Delle Monache, D. Di Gioacchino, V. Fafone, A.C.Fauth, G. Frossati,C.Ligi,A. Marini, G. Mazzitelli, G. Modestino, G. Pizzella, L. Quintieri,

F. Ronga, P. Tripodi, P. Valente

Laboratori Nazionali di Frascati

Nautilus Cosmic Ray veto system

Streamer Tubes

PVC-rectangular cells (8 per tube) with cross section 3X3 cm2

Cu-Be 100µm diameter anode

ΔV=5550 V

Gas mixture:40%Ar+60% Isobuthane

In 1992 NAUTILUS was equipped with a cosmic ray veto system

Nucl.Instrum.Meth.A355:624-631,1995

1999

Nautilus answer to 46 Showers with multiplicity

M≥ 15⋅103 vs time (zero @ time arriving of cosmic showers)

Phys. Rev. Lett. 84 (2000) 14.

The NAUTILUS G.W detector has recorded signals due to the

passage of cosmic rays.

20σRAP

Scientific

Motivation

Thermo-acousticModel

Unfiltered

signal (V2)

The signal

after

filtering

(kelvin)

Real data: the arrival of a cosmic ray shower on NAUTILUS

We use mainly the "adaptive matched filter" to extract a delta-like signal from the noise

(P Astone et al. Nuovo Cim 20 C 1997).

GPS and Radio clocks are used for timingTime behaviour of the largest coincident Nautilus event

Phys. Lett. B499 (2001) 16.

Unfiltered Signal

(V2)

Filtered Signal(K)

RAP

Scientific

Motivation

Thermo-acousticModel

2000

Large signals at higher rate than expected

has been observed

Anomalous Signals

Comparison between calculations and measurements

Hadrons + T.A.M unable to explain the data

Thermo-acoustic model

Carlo Ligi SIF 2003 – Parma, 20 settembre 2003

The energy deposited by a particle is

converted in a local increase of temperature

dT = dE / rCVV

dP = g dE / V

g ≡ bV / cTCV is the Grüneisenparameter

Scientific MotivationsScientific Motivations

Thermo-acoustic model

En ! g 2 (dE/dx)2 F

n2

En

The Thermo-acoustic Model

predicts very small signal for

present resonant gravitational

wave detector sensitivity.

It has been proven effective at

room temperature by previous

experiments (Rev. Sci. Instrum. 71

(2000) 1345-1354 and previous papers)

thermal and mechanical

energy loss

Geometric factor

E ∝

(dE

dx

)· G

2

Local Heatingalong the trajectory

dT =

dE

ρCV

En =1

2·

l2

V·

Gn

ρc2

l

.Σ2

Eccitation ofnatural modes

Energy lostfor ionization

Local impulse ofpression

dp = γdE

V

Thermo-acoustic model(2)En =

1

2·

l2

V·

Gn

ρc2

l

.Σ2

γ =

β · kt

ρ · CV

GruneisenFactor

Gn ∝

∫l

(∇ · u) dlShapeFactor

Source Term

Σ = γ ·

dE

dx

Riportare animazione

The Shape Factor Gn: analytic and numerical estimation

First Longitudinal Mode

path ANALITIC ANSYS RATIO

Horizontal 0.2955 0.2865 1.0314

vertical 0.4641 0.4520 1.0268

Inserire grafico della meshatura

∇.u = 0 ∇u = BnJ1(Klr) cosϑ eiγz

∇u = AnJ0(Klr) eiγz

Torsional Flexural Longitudinal

Particle density >300/m2

308 stretches selected (Feb-Jul 2000)

968 stretches selected (Mar-Sep 2001)

2000

2001

Data vs Thermodynamic temperature

Why T.M.A doesn’t work with 2000 data

Feb-Jul 2000 308 stretchesMar-Sep 2001 968 stretches

particle density>300/m2

Incoherent hypothesis with Explorer’s 2003 data

2000

2001

Super-

conductor

Normal

2001

Data collectedagain in agreement with

T.M.A.

Why 2000 so special?

Carlo Ligi SIF 2003 – Parma, 20 settembre 2003

(End of 2001) Proposal LNF-01-027(IR)

In order to understand:

• enhancement of g Grüneisen factor

in super-conducting state

• enhancement of energy conversion (dE/dx)in super-conducting state

• exotic component of cosmic rays in (dE/dx)(nuclearites, monopoles)

GEANT simulation

En ! g 2 (dE/dx)2 Fn2

RAP PROPOSAL

Unexpected response of a possible metastable state of a massive superconductor to the passage of particles:

Enhancement of g Grüneisen factor in super-conducting state

Enhancement of energy conversion (dE/dx) in super-conducting state

Something strange in the cosmic rays composition at the energy of interest (exotic nuclei, monopoles, etc).

Creep phenomena: impulsive release of accumulate internal tension

Possibilities to explain data:

CSN II, Settembre 2003

DAFNE Beam Test Facility

e- / e+ naverage= 1 - 1010 particles

Energy: 20–800 MeV e-/e+

Repetition rate: 50 Hz

Pulse Duration: 1–10 ns

1% energy selection

100 m2 Experimental Hall

DAΦNE Beam Test Facility

e- e+

BTF experimental hall 100 m2

n(average)=1-1010 particles

Energy 20-800 MeV

Repetition rate:50 Hz

Pulse duration 1-10 ns

1% energy selection

Mechanical structure needed to host and suspend the cryostat

The cryogenic and vacuum system

The suspension system

The cylindrical test mass

The read-out and DAQ

Experimental setupThe main component of the detector are:

Mettere come sfondo qualche immagine del criostato

Commercia

l

Cryosta

t:

H=3.2 m

D=1 m

RAP Installation

RAP installed @BTF

in June 2003

Suspension System, Test Mass,Cryogenic System

KADEL Liquid Helium Cryostat

+ Dilution Refrigerator

Working Temp: 100 mK

Material Al 5056 barL 50 cmФ 18 cmM 35.17 kgf1L 5096 Hz @ 300 K

Test Mass7 OFHC copper masses1 OFHC copper tube

Attenuation: –200db@ 5KHz

Suspension

First run @ 300 K

CSN II, Settembre 2003

9.4 107 electrons @ 510 Mev

Energy released in the bar=1.74 10-3 J

Expected vibration in the

1L mode=4.13 10-13 m

CSN II, Settembre 2003

9.4 107 electrons @ 510 Mev

Energy released in the bar=1.74 10-3 J

Expected vibration in the

1L mode=4.13 10-13 m

9.4 ⋅1010

electrons @ 500 MeVEnergy released in the bar 1.7 ⋅10-3 JAmplitude of 1L mode =4.13⋅10-13 m

0.70 +/- 0.11measurement

theory=

First Rap Cool-down

Date Temperature

28/05/2004 300 K

5/06/2004 77 K

9/6/2004 8 K

10/6/2004 4.4 K

14/06/2004 77 K

17/06/2004 300 K

Frequency of first longitudinal mode

Frequenza 1 Longitudinale vs Temperature

5050

5100

5150

5200

5250

5300

5350

5400

5450

0 50 100 150 200 250 300 350

Merit Factor Q vs TemperatureMerit Factor Q vs Temperature

0

100000

200000

300000

400000

500000

600000

0 50 100 150 200 250 300 350

Data Analysis in progressCorrelation between the observed values (on-line S.A.)

and the predicted ones

0

10

20

30

40

50

0 10 20 30 40 50 60

T = 300 K

y = -0.4506 + 0.75763x R= 0.98351

X m

eas. (*

10e-1

3)

[m]

X expec. (* 10e-13) [m]

T=300 K

0

10

20

30

40

50

0 10 20 30 40 50

T = 77 K

y = -0.37395 + 0.93641x R= 0.99624

X m

eas. (*

10e-1

3)

[m]

X expec. (* 10e-13) [m]

T=77 K

0

10

20

30

40

50

60

0 10 20 30 40 50 60

T = 4K

y = -0.30412 + 1.1366x R= 0.9922 X

meas. (*

10e-1

3)

[m]

X expec. ( *10e-13) [m]

T=4 K

Preliminary Comparison with other results

GRII (Roma), Italy 30 Sep 2004

Data analysis in progress…

0

5

10

15

20

25

30

35

0 2 104

4 104

6 104

8 104

1 105

1.2 105

1.4 105

A [mV]

energy deposited [TeV]

y = m1*m0

ErrorValue

3.3865e-060.00026997m1

NA147.69Chisq

NA0.99091R

example of data correlation

amplitude measured on-line

from spectrum analyzer

comparison between

experimental data and theory

for pure amorphous Aluminum

First longitudinal mode amplitude/deposited energy

T ~ 4 K

0

1 10-10

2 10-10

3 10-10

1 10 100 1000

measurement 2003

Nikhef 1998

online meas. 2004

theory 1D

theory 3D

[J/m]

temperature

m/J

Temperature

Good agreement between 1D / 3D calculation results and measured values

Conclusion and future plans

Filtering Optimization + accurate Data Analysis and Errors Evaluation

Work in Progress:

Results:First Measure @ low Temperature. Good agreement with previous experiments (room temperature) and theory

Futureplan:

Installation and Measurement with Dilution Refrigerator in super-conducting state before end of 2005

O ne o f th e la rge st ev ent w ith th e 5

kH z acqui s ition - 9 ke lv in ( Jun e

2000)

• G PS timi ng : 200 µs ec pre ci sion

• The even t is s o big th a t no soph isti ca te d

filt er ing is ne cess aryEvento 4298 60222

Time (seconds). The cosmic ray is at T=300 sec

Raw Data of the largest signal recorded

Mode energy

[K]

Time [s]

The Thermo-Acoustic model predicts very small signal signal for resonant gravitational wave @ present sensitivity

The average NAUTILUS signal Eobs

vs the theoretical value :

Eth = !2 4.7 10-10 K

Zero threshold search

Tbar=1.5 K (Mar-Sep 2001)

2001 Dependence on NAUTILUS thermodynamic temperature

E obs

Eth

RAP read-out system

JFET amplifier

1nVHz-1/2@ 5KHz bandwidth 25KHz

2 piezo-electric ceramics

(PZT24, 1cm2x0.5cm)embedded in the test mass

α =2πfl

C2 + Ccavi

·

√MC1

2

T=300 K 1.35e+10 V/m

T=77 K 1.5e+10 V/m

T=4.4 K 1.33e+10 V/m

Calibrazioni

Circuito elettrico equivalente

C1= elasticitàL1= massa risonanteR1= dissipazioneC2= capacità del traduttore o piezoelettrico

v(t) = αx(t)

Obiettivo: determinare la costante di

accoppiamento elettro-meccanio vs Temperatura

α

Event Rate ~ 2 order of magnitude

higher than expected

Energy ~ 2 order of magnitude higher than that one computed with the

thermo-acoustic model