1. The search for and registration of the superweak angular ground motions
JINR: J. Budagov, M. Lyablin., G. Shirkov.
CERN: J-Ch. Gayde, D. Mergelkuhl

2. The principle of construction of the registration device to measure the seismic slope of the Earth’s surface. θ ψ
Laser
QPR
Original
direction of the reflected beam
Base
Cuvette with a liquid
The surface of the liquid
in case of horizontal basis
with tilt base
Direction
the reflected beam
after tilt base
Main principle : use reflected laser beam from horizontal surface liquid

3. Experimental set-up L-laser QPr-quadrant photodiode O,O1,O2- basesC О1 О2
Sensor S О SM CF
50 cm
L-laser
QPr-quadrant photodiode
O,O1,O2- bases
SM-semitransparent mirror
C-calibration screw
CF- collimator with changeable focus
frequency internal of 10-4Hz÷1Hz
The achieved inclinometer angular precision is rad

4. The inclinometer tests The angular component of the Earth quake
The Earth quake in Siberia on February 26, 2011
Average amplitude of quake in Siberia was 6.5 units
The distance to Geneva (on the Earth surface) was determined: L=6160km
Calculation time of Earth quake begin Tcalc=6h 21 min in Siberia (world time)
practically coincides with the published Tpub=6h 17min (world time)
Amplitude angular oscillations consisted rad

5. Earth surface single oscillation.
The observation of an earth surface “single inclination” effect
Amplitude consisted few μrad

6. Earth surface oscillations of an industrial noise origin
Industrial origin noise:
high activity of auto– traffic,
works in the neighboring (with our set-up) Lab room,
people movement close to detecting set-up etc.

7. Calculation sigma value angular ground motion from industrial noise
Amplitude consisted
in work period 0.3 μrad
Amplitude consisted
In dinner time 0.04 μrad

8. Measurement deformation value concrete floor
Concrete floor inclination due to man presence in 3 meters distance
from the experimental set-up
Amplitude consisted 0.3μrad

9. The microseismic peak observation by ground angular motion
The seismogram of an earth surface angular oscillation at the “microseismic peak” frequency

10. Fourier analyses oscillation at the “microseismic peak”
Amplitude Earth surface oscillation at the “microseismic peak” frequency
consist 0.03μrad with frequency fd=0.13Hz
Inclinometer sensitivity estimate on the level of ≈5·10-9 rad

11. The long experimental setups space location stability and an earth surface angular oscillations
θmp
Linear accelerator-collider
Experimental Hall
The Earth surface fixed time picture:
surface deformation induced by the standing waves originated by the interference of “microseicmic peak”
Line of horizon
The accelerator-collider positioning on the earth
surface deformed by the microseismic peak wave
Different accelerator parts are inclined relative to the ”basic” horizontal
line and consequently particle beams going through the focusing elements
leave them with some angular spread θmp relative to the nominal.
As a result it leads to random motion position focus es accelerators
If we can stabilize the angular movements of the accelerator with an accuracy of 10-9nrad we will be able to stabilize position its focuses to within 50 nm

12. Conclusion
The ground motion was studied by the detection of an earth surface angular oscillation. Instrumentally method is based on the conceptually new design laser inclinometer using the reflecting surface liquid, as a space stable (horizontal) reference level. The achieved inclinometer measurement precision was experimentally proved to be ≈5·10-9 rad.
The achieved laser inclinometer sensitivity was proved by observation (in Geneva) of:
Ground 2µrad oscillation caused by the Siberian earth quake (6160 km);
Single 1÷2 µrad oscillation of origin to be studied;
Industrial origin noise of about 10-7 rad amplitude;
Microseismic peak for the first time recognized as a ground ≈ 10-8rad angular oscillation at 0.13Hz frequency.
The last observed effect if properly “compensated” by adequate instrumental method could give significant colliders luminosity increase by reduction of beams intersection area to about 50µ level (an estimate) due to some suppression of the lateral focus effect.
The instrument of this sort may happen to be useful for modern high precision research equipment stabilization, for example, of large telescope to reach an extreme resolution with them.