KEKB Super KEKB

LER HER LER HER GAIN

Energy (GeV) 3.5 8.0 4. 0 7.0

Half crossing angle

(mrad)

11 41.5

Holizontal emittance

(nm)

18 24 3.2 5.3

Vertical -function

at IP(mm);

5.9 5.9 0.27 0.31 ×20

Beam currents (A); 1.64 1.19 3.6 2.6 ×2

Beam-beam

parameter;

0.09 0.09 ×1

Luminosity(cm-2s-1) 2.1×1034 8×1035 ×40

KEKB and SuperKEKB machine parameters

BB

Factory machine

Energy frontier

machine

Super KEKB

SuperKEKB requires precise

alignment order of 100m.

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)

Horizontal Vertical Magnet position shifts in the

horizontal direction.

Comparison between Feb.2010 and

June 2011.

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]

[mm]

2011.3.11 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

9C

9SM5

12C

3C

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.

# place latitude (N) longitude (E) ellipsoidal

height (m)

Slope

distance (m)

0 Tsukuba-1 36° 06' 22.01819“ 140° 05' 13.91636“ 67.6353 --

1 3C 36° 09' 12.93507“ 140° 04' 36.50100“ 78.0207 0

2 6C 36° 09' 01.87503“ 140° 04' 14.16084“ 77.6814 654.2807

3 9C 36° 09' 20.13795“ 140° 04' 00.35185“ 78.0322 930.4878

4 12C 36° 09' 31.33353“ 140° 04' 22.86363“ 78.0659 661.6660

5 6SM3 36° 09' 02.56037“ 140° 04' 26.55713“ 73.6987 405.0514

6 9SM5 36° 09' 12.02093“ 140° 04' 00.04796“ 74.5407 911.6645

7 12SM7 36° 09' 31.56873“ 140° 04' 12.85889“ 74.5877 824.0912

8 Bldg-3 36° 08' 58.23513“ 140° 04' 26.99974“ 103.0083 512.1887

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. 2010 and May 2011.

8mm

Magnet position shifts

in the horizontal direction

Comparison between

Nov. 2010 and May 2011.

8mm

The south

arc section

• Vertical distance ~20m

• Vertical position is

confirmed within few mm

Tunnel

The sight line for the tunnel