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Giulia De Bonis University “La Sapienza” Rome, ITALY. International ARENA Workshop May 17-19, 2005 DESY, Zeuthen. Preliminary Results on Hydrophones Energy Calibration with a Proton Beam. Results at an intense low-energy proton beam in ITEP (Moscow),
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Giulia De Bonis University “La Sapienza” Rome, ITALY International ARENA Workshop May 17-19, 2005 DESY, Zeuthen 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
Overview • Hydrophones Characterization (Frequency Response) • Hydrophones Calibration on Proton Beam • Future Developments
BENTHOS (prototipe) L = 15.5 cm d = 2 cm Piezo-Electric HYDROPHONES RESON 4042 (modified) previously used for 6 months at 2000 m depth. Both hydrophones are pre-amplified (~ 30 dB)
Frequency Response -the Hydrophones Sensitivity Test at IDAC (CNR – Roma) Data Analysis Results
__ 6 m __ __ 4 m __ __ 5.5 m __ CALIBRATION - Frequency Response IDAC – Institute of Acoustics “O. M. Corbino” – Rome (Italy) http://www.idac.rm.cnr.it/ UAL - Underwater Acoustics Laboratory water tank (fresh water) with dimensions: 6.0 m (length 4.0 m (width) 5.5 m (depth) remotely-operated transducer positioning system capable of handling weights up to 100 kg on two independent carriages
Experimental Set-Up Hydrophone The signal source (Reson ACS 9060) produces a 5KHz to 25 KHz sine wave (frequency sweep with a step of 0.5 KHz). Spherical Transducer (Model ITC 1007) 1.5 ms L=2.8 m (depth) d=1 m (distance)
CALIBRATION - Frequency ResponseRESULTS -173 dB re 1V/1mPa -183 dB re 1V/1mPa Reson Benthos Hydrophones sensitivity is measured in dB re 1V/1mPa
Nprotons/spill ~ 1010 Eprotons = 100 MeV, 200 MeV up to 1018 eV deposited per spill Protons Interaction in Water -the Acoustic Signal -Test at ITEP (Moscow) Proton beam - Preliminary Data Analysis Results
Particles Interaction in Water:the Acoustic Signal “ instantaneous ” & localized energy deposition local heating of the medium Local density variation PRESSURE WAVE
The Bragg Peak If 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.
R BENTHOS p Injection Tube Beam Output T B RESON ITEP Transducer Positioning System Beam Output __ 52.3 cm __ __ 50.8 cm __ __ 94.5 cm __ ITEP Experimental Set-up June 2004 Dimensions 50.8 cm × 52.3 cm × 94.5 cm The 90% of the basin's volume is filled with fresh water. NO control on temperature. V.Lyashuk and A.Rostovstev group, G. De Bonis, G. Riccobene, R. Masullo and A. Capone Data Acquisition with 3 different hydrophones B -173 dB re 1V/1mPa R -183 dB re 1V/1mPa T -133 dB re 1V/1mPa Collimator
RESON Z [ cm ] BENTHOS ITEP RESON BENTHOS X [ cm ] p Hydrophones Configuration (Monte Carlo Simulation)
TTX Data BENTHOS Hydrophones RESON ITEP BCT Beam Current Transformer
A ~ 45 mV ~ 50 ms Hydrophones Data - a Zoom View Electro-magnetic induced pulse Typical pulse collected with 1010 protons @ 200 MeV Acoustic Pulse related to protons interaction Bipolar Shape
Hydrophones Data AnalysisFIT Operation BENTHOS RESON ITEP
Ebeam = 100 MeV Nprotons= 2. 5·1010 Ebeam = 200 MeV Results - LINEARITY Linear Fit Bipolar Amplitude BENTHOS Hydrophone Proton Intensity Total deposited energy = 108 [eV]• 2. 5·1010 =2.5 ·1018 eV
RESON Hydrophone E = 100 MeV E = 200 MeV Results - LINEARITY Linear Fit
ITEP Hydrophone E = 100 MeV E = 200 MeV Results - LINEARITY Linear Fit
The BCT gives a measure of the number of protons BEFORE the collimator Results show a collimator diameter dependance 0 0.5·1010 2.0·1010 2.5·1010 1.0·1010 1.5·1010 Beam Intensity [Nprotons] BENTHOS Data – E=100 MeV Collimator Diameter Dependance
Number of entering protons The voltage signal measured at the BCT channel is proportional to the number of protons 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. More over, collimators, located downstream the BCT, are used to modify the number of protons interacting in water. We considered collimator with diameter f = 2, 3, 5 cm).
0.5·1010 2.5·1010 1.5·1010 0 2.0·1010 1.0·1010 Results (taking into accounts the effect of collimators…) Ebeam= 100 MeV Nprotons ENTERING THE BASIN
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