Preliminary Results on Hydrophones Energy

Calibration with a Proton Beam

Results at an intense low-energy proton beam in ITEP (Moscow),

special thanks to Vladimir Lyashuk and Andrei Rostovstev group

• Nprotons ~ 1010

• Eprotons = 100 MeV, 200 MeV

International ARENA WorkshopMay 17-19, 2005DESY, Zeuthen

Giulia De BonisUniversity “La Sapienza”Rome, ITALY

Overview

• Hydrophones Characterization (Frequency Response)

• Hydrophones Calibration on Proton Beam

• Future Developments

BENTHOS (prototipe)

L = 15.5 cm

d = 2 cm

RESON 4042 (modified)

Piezo-Electric HYDROPHONES

previously used for 6 months at 2000 m

depth.

Both hydrophones are pre-amplified (~ 30 dB)

Frequency Response -Frequency Response -

the Hydrophones the Hydrophones

SensitivitySensitivity

Test at IDAC (CNR – Roma)Data Analysis Results

CALIBRATION - Frequency Response

IDAC – Institute of Acoustics “O. M. Corbino” – Rome (Italy)http://www.idac.rm.cnr.it/

UAL - Underwater Acoustics Laboratory

remotely-operated transducer positioning system capable of handling weights up to 100

kgon two independent carriages

water tank (fresh water) with dimensions:

6.0 m (length

4.0 m (width)

5.5 m (depth)

Experimental Set-Up

HydrophoneSpherical Transducer

(Model ITC 1007)

d=1 m(distance)

L=2.8 m(depth)

The signal source (Reson ACS 9060) produces a 5KHz to 25 KHz sine wave (frequency sweep with a step of 0.5 KHz).

1.5 ms

CALIBRATION - Frequency Response

RESULTS

Benthos Reson

Hydrophones sensitivity is measured in dB re 1V/1Pa

-173 dB re 1V/1Pa -183 dB re 1V/1Pa

Protons Interaction in Protons Interaction in

Water -Water -

the Acoustic Signalthe Acoustic Signal

-Test at ITEP (Moscow) Proton beam- Preliminary Data Analysis Results

Nprotons/spill ~ 1010

Eprotons = 100 MeV, 200 MeVup to 1018 eV deposited per spill

Particles Interaction in Water:the Acoustic Signal

“ instantaneous ”& localized

energy deposition

local heating of the medium

Local density variation

PRESSURE WAVE

The Bragg PeakThe Bragg PeakIf the proton energy is in the range 100-200 MeV, the most of the primary proton energy is deposited at the Bragg Peak.

The Bragg Peak is a good approximation of a localized high-density energy deposition in water. Considering the Bragg Peak one can simulate an acoustic source.

ITEP Experimental Set-up June 2004

Dimensions50.8 cm × 52.3 cm × 94.5 cm

The 90% of the basin's volume is filled with fresh water. NO control on temperature.

Beam Output

Transducer Positioning

System

Data Acquisition with 3 different hydrophones

B -173 dB re 1V/1Pa

T -133 dB re 1V/1Pa

R -183 dB re 1V/1Pa

V.Lyashuk and A.Rostovstev group,G. De Bonis, G. Riccobene, R. Masullo and A. Capone

B

T R

pInjection Tube

Beam Output

BENTHOS

RESONITEP Collimator

X [ cm ]

Z [ cm ]

BENTHOS

RESON

Hydrophones Configuration

BENTHOS

ITEP

RESON

p

(Monte Carlo Simulation)

TTX Data

BENTHOS

RESON

ITEP

BCTBeam

CurrentTransformer

Hydrophones

Hydrophones Data - a Zoom View

~ 50 s

A ~ 45 mV

Acoustic Pulse related to protons interaction

Bipolar Shape

Electro-magnetic induced pulse

Typical pulse collected with 1010 protons @ 200 MeV

Hydrophones Data Analysis

FIT Operation

22

2

)(

10

)(

Px

MAX ePx

Ayy

21 )(

2

1

0

Px

MAX eAyyBENTHOS

RESON

ITEP

Results - LINEARITYBENTHOS Hydrophone

Ebeam = 200 MeV

Ebeam = 100 MeV

Nprotons= 2. 5·1010

Linear Fit

Total deposited energy = 108 [eV]• 2. 5·1010 =2.5 ·1018 eV

Proton Intensity

Bip

ola

r A

mp

litu

de

Results - LINEARITY

E = 200 MeV

E = 100 MeV

RESON HydrophoneLinear

Fit

Results - LINEARITY

E = 200 MeV

E = 100 MeV

ITEP HydrophoneLinear

Fit

Collimator Diameter Dependance

The BCT gives a measure of the number of protons BEFOREBEFORE the collimator

BENTHOS Data – E=100 MeV

Results show a collimator diameter dependance

Beam Intensity [Nprotons]

0.5·1010 0 1.5·1010 1.0·1010 2.5·10102.0·1010

Number of entering protons

More over, collimators, located downstream the BCT, are used to modify the number of protons interacting in water. protons interacting in water.

We considered collimator with diameter = 2, 3, 5 cm).

The voltage signal measured at the BCT channel is proportional to the number of protons in the emitted bunchprotons in the emitted bunch.

One can calculate Nproton using the formula:

Nproton = ABCT [ V ] · 2 · C ·108

where C is a parameter depending on machine settings; the C-value is given by machine technicians.

NNprotons protons ENTERING THE BASINENTERING THE BASIN

Results(taking into accounts the effect of

collimators…)

Ebeam= 100 MeV

0.5·1010 0 1.5·1010 1.0·1010 2.5·10102.0·1010

Future Plans

• Simulation (Geant4) of proton beam energy deposition in water

• Simulation of acoustic signal formation • Development of a tool for open sea

hydrophone calibration (controlled sparker)

• Simulation of acoustic signal from UHE neutrino induced showers in sea water