KEKBSuper KEKB LERHERLERHER GAIN Energy (GeV) Half crossing angle (mrad) Holizontal emittance (nm) Vertical  -function at IP(mm); ×20 Beam currents (A); ×2×2 Beam-beam parameter; 0.09 ×1×1 Luminosity(cm -2 s -1 )2.1× ×10 35 ×40 KEKB and SuperKEKB machine parameters Factory machine Energy frontier machine Super KEKB SuperKEKB requires precise alignment order of 100  m. But, after the earth quake, we lost reliable monuments in the KEKB tunnel completely! CP violation ~2010 ~2020 GPS NETWORK FOR SuperKEKB MAIN RING H. Iinuma, Y. Ohsawa, M. Masuzawa (KEK), N. Abe, T. Ariyama, K. Mishima (PASCO Corporation) Data from Geospatial Information Authority of Japan (GSI) Tsukuba  0.51m Compared to Shimane (1000km away) Tsukuba   0.1m Compared to Shimane (1000km away) HorizontalVertical Magnet position shifts in the horizontal direction. Comparison between Feb.2010 and June Oho exp. hall Fuji exp. hall Y X Arrows not to scale Max. deviation is about 3 mm in both X & Y directions. Direction changes at the expansion joints indicated by red arrows. [mm] Tohoku earthquake Seismic intensity at KEK was lower 6 Deformation Surveying By Global Positioning System How badly the KEKB ring is deformed? I.Eight GPS antennas are mounted on the roof of the access buildings to the SuperKEKB main ring (3C, 6C, ….) which can access to the KEKB tunnel. II.As a fixed point, we use one of the GPS-based control stations (Tsukuba-1)of Geospatial Information Authority of JAPAN (GSI). III.Distance between Tskuba-1 and the KEKB is 5 km. IV.Direct views between antennas (ex. From Bldg.3 to 3C, 6C, …) allow us to compare with Total Station. They agrees within 3mm (<10ppm). Tsukuba-1 KEKB ring 5km 6C 6SM3 9C9C 9SM5 12C 3C3C 12SM7 KEKB ring Bldg.3 IV.To connect surface and tunnel networks, i.e., eight GPS points and tunnel monuments, we set special monuments on the wall and floor of service buildings (see the right figures). V.Stability of slope distances between GPS antennas reaches the sub-millimeter level. VI.Preliminary analysis indicates a good agreement between the GPS network and the underground tunnel network (within 3mm). VII.The new surveying network in a tunnel is designed by the 24 hours daily monitoring of this GPS network. #placelatitude (N)longitude (E)ellipsoidal height (m) Slope distance (m) 0Tsukuba-136° 06' “ 140° 05' “ C36° 09' “ 140° 04' “ C36° 09' “ 140° 04' “ C36° 09' “ 140° 04' “ C36° 09' “ 140° 04' “ SM336° 09' “ 140° 04' “ SM536° 09' “ 140° 04' “ SM736° 09' “ 140° 04' “ Bldg-336° 08' “ 140° 04' “ Access building Laser tracker Special monuments on the wall and floor GPS: Leica Geosystems (GS10) L1, L2 Position accuracy: horizontal <3mm, vertical <6mm (from the spec sheet) Leica GPS Large deformation Above of KEKB Ring Magnet position shifts in the horizontal direction Comparison between Nov and May mm Magnet position shifts in the horizontal direction Comparison between Nov and May mm SuperKEK B The south arc section Vertical distance ~20m Vertical position is confirmed within few mm Tunnel The sight line for the tunnel