At this time, he reported a measurement at D3 and a coherency measurement between the four points. Data sampling frequency and duration are 100Hz and 600sec, respectively. At the D3, P4 and P3 were set on ground surface at distances of 4m and 15m from route 408, respectively. P2 and P1 were set on the floor and -10m underground floor, respectively, in a building of "D3" power station. Ground motions were measured every hour in a day. As expected, the P1 was the most quiet, where the GM tolerances (250nm at 0.1Hz, 10nm at 10Hz) were only satisfied during a day. The P4 was the noisiest, which was actually noisier three times than the P3 at f>10Hz. Good correlation in the daily variations was observed between measurements and total weight rather than total number of cars passing through on the route 408 , assuming weights of car, truck and big truck are 1.5, 10 and 30 tons, respectively. The vehicle traffic has been recorded on a video tape. Horizontal attenuation was observed to be 3/5~2/3 for 11m from P4 to P3 at f=0.1~10Hz. As a resonance frequency of soil corresponding to GM amplification in earth quake, H/V PSD ratios were also calculated to be about 6 at a peak at f=0.5Hz. Finally, good coherency in large distances, e.g. 1km of D9-D3, were observed at f<0.3Hz.
(2) FEATHER: Status Report (N.Delerue, KEK)
(transparencies, 13 pages, pdf ,815KB )
Nicolas reported on the progresses of kicker design, estimation of model delays, MATLAB simulation and beam tests.
He summarized and will publish the kicker design in a KEK report. The technical drawings have been reviewed and validated, while the impedance at bolting points will be very low.
Delay times in the FEATHER have been estimated as in a following table.
------- Delay time in nsec -------------------- Model: Simple Delay cable 5cablesx1.4= 7 7cablesx1.4= 9.8 HH107 2 HH107 = 0.5 4 HH107 = 1.0 Att. < 1.0 < 1.0 Amplifier estimated 20 20 Total 28.5 31.8 ------------------------------------------------So, the amplifier dominates in above list and next major component is the cable delay to be improved with shorter cables. The fast amplifier is primary requirement for the purchase. He simulated the feedback models by using MATLAB including the beam signals with position offsets. In the beam test, he has investigated communication problems with the GPIB devices and the ATF_CONTROL. The GPIB problem were fixed and the software has been tested. The ATF_CONTROL problem has been understood and seems to be fixed but more tests are needed. Next beam test will be in October.