1. Acoustics (Activity of ITEP group) 1. Proton beam measurements
V.I. Albul 1), V.B. Bychkov 1), V.S. Demidov 2), E.V. Demidova 2), K.E. Gusev 2),
N.K.Krasnov 1), A.F. Kurchanov 1), V.E. Lukyashin 2), V.I. Lyashuk 2), E.G. Novikov 2),
A.A. Rostovtsev 2), A.Yu. Sokolov 2), S.S. Vasil’ev 1), D.N. Zaborov2)
1) Mendeleev All-Russia Research Institute for physics-technical and radio-technical measurements,
Mendeleevo, Moscow region
2) Scientific Center of Russian Federation Institute of Theoretical and Experimental Physics ( ITEP ),
Moscow
1. Proton beam measurements
2. Acoustic signal simulation
3. Sensitive hydrophone manufactiring
4. Experiment at the Lake Baikal

2. Two experiments with proton beam at ITEP
Proton beam: 200 MeV / ~70 ns / 108 – 1012 protons / Diam = 1-5 cm
Measurement of the signal
shape and propagation inside the
water volume.
II. Measurement of a tempera-
ture dependence of the acoustic
signal formation. P P

3. Propagation of the acoustic signal
A structure of the acoustic field as measured by a movable
hydrophone synchronized with the proton beam.
Sound sources
Proton
beam
Time [mks]
A: acoustic trace from
the absorbed beam
B-D: acoustic signal
from the Bregg peak
A-C: acoustic signal
from beam entry point
These 3 sound sources define a structure of the recorded signals.

4. Measurement of the temperature dependence
The temperature was varied between about 1o C and 8o C
At T~4oC the acoustic signals change polarity and get broader
Amplitude
~4oC

5. The model underestimates the ITEP proton beam measurements
Simulation of an acoustic signal
calculations
energy deposition in water E = 3.2 E+17ev, distance 0.32m (compared to the model of G.A.Askarian )
The model underestimates the ITEP proton beam measurements
by factor of 2

6. Deep water hydrophones ( ITEP, Moscow), used for searching of signals from extensive atmospheric showers and acoustic investigations in the experiment BAIKAL during expeditions of years

7. Scheme of the acoustic experiment
lake Baikal
Scintillator detectors (EAS trigger)
March, 23 – April,
50 m
30 m
50 m
H1 (4 m)
B4 (4 m)
B3 (4 m)
G8 (9 m)
G7 (9 m)
B6 (4 m)
H2 (9 m)
H3 (14 m)
H4 (19 m)
hydrophones (name and depth shown)

8. Hydroacoustic antenne of ITEP (Moscow), used for searching of signals from extensive atmospheric showers in the experiment BAIKAL

9. An example of detected sound (hydrophones H1-H4,G7,G8)
Arbitrary units

10. An example of detected sound (hydrophones B4,B6,B3)
Arbitrary units
* This example presents a background signal (not a signal from EAS)

11. Distribution of the delays in the triangle of hydrophones located on a horizontal plane (H2-G7-G8)
The ellipse corresponds to real physical sounds located near horizontal plane φ
Sounds coming from or through the center of the experimental setup

12. Angular distribution of sources seen from H2, calculated from arrival times of signals at (H2-G7-G8)
sin 
3 “clusters”
 = 90º surface noise
 = 0º ???
 = -10º ???
noise channeling below ice due to temperature gradient ? 
t8-t2 = ((d8-d2)/v)*cos *cos ( s - 82)
t7-t2 = ((d7-d2)/v)*cos *cos ( s - 72)

13. Acoustic noise from Baikal water