Status Report on Survey and Alignment

of J-PARC after the earthquake

N. Tani, T. Morishita, S. Meigo, M. Harada, H. Stefanus

JAEA / J-PARC

M. Shirakata, T. Ishii, Y. Fujii, Y. Shirakabe

KEK / J-PARC

1

Crustal movement data by the earthquake

Geospatial Information Authority of Japan (GSI)

Crustal movement by the Tohoku earthquake in 2011.

http://www.gsi.go.jp/chibankansi/chikakukansi_tohoku2.html

J-PARC area moved 91cm to east, 16cm to south and settled down by 36cm

Horizontal direction Vertical direction

2

At J-PARC facility precise traverse survey and leveling are being

implemented every two years. The last survey before the

earthquake was in August 2010. GPS observation network this time

is the same as that of the precise traverse survey last year.

Observation time

Primary reference point (red line): 4 hours

Secondary reference point (blue line): 2 hours

Equipment：Trimble 5700

However traverse survey was carried out to the secondary

reference points set in the building using TDA5004 and evaluated

referring to the reference point obtained by GPS survey.

GPS survey of J-PARC facility

地上の測量網

側壁基準点

加速器ホール基準点網

床基準点

地上とのリンク基準点

Through hole

Main tunnel

Ground level

Ground surveying network

Base point

Floor point

Observation of through hole

3

Result of GPS survey（North area of J-PARC）

Displacement of reference points in Linac tunnel

Linac_01 : 6.81mm (west north-west)）

Linac_02 : 6.18mm (south)

Displacement of reference points in Linac building

(1st floor)

LT01 : 2.04mm (east south-east )

LT03 : 1.10mm (west)

⇒Tunnel expanded to north and south direction

due to the earthquake.

Displacement of reference points in RCS

tunnel

RCS_01 : 6.6mm（northwest）

RCS_02 : 19.35mm（east）

RCS_03 : 9.68mm（northeast）

⇒Tunnel expanded to east and west

direction due to the earthquake.

Displacement vector (red): reference points on the ground and roof of the building

Displacement vector (blue):reference points in the tunnel

Survey accuracy:+-5 mm

4

Result of GPS survey （Central area 1 of J-PARC）

Displacement of reference points in 3NBT tunnel

RCS_03 : 9.68mm（northeast）

3NBT_01 : 10.8mm（north）

3NBT_02 : 10.08mm（west-borthwest）

⇒Moved about 10mm toward RSC side

due to the earthquake and rotated clockwise

Displacement of reference points in MLF building

MLF_roof_01 : 33.02mm（south）

MLF_roof_02 : 22.74mm（south-southeast）

MLF_roof_03 : 23.07mm（southeast）

hannyu : 22.21mm（southeast）

⇒Moved about 20mm to south due to the

earthquake and rotated counterclockwise

5

10mm

Neutrino-monitor

building 1F

Muon pit

underground

Target-station

building 1F

Accuracy: +-5mm

These points are reference points of Neutrino beam line.

It was confirmed that these points did not move enough to affect the experiment.

(Accuracy of a few mm is acceptable at the lower section of Target station.)

Points of through-holes cannot be used due to the earthquake

⇒P1, T2 an d M2

Result of GPS survey （Central area 2 of J-PARC）

6

MR_02

MR_03

MR_06MR_04

MR_01

MR_05

HD-SY

Displacement of reference points in MR tunnel

MR_02 : 11.61mm（south-southeast）

MR_03 : 9.53mm（north-northwest）

MR_04 : 5.41mm（north）

MR_06 : 10.6mm（northwest）

⇒Points except for MR_03 and MR_04 are

located outside of the main tunnel separated by

the expansion joints.

Therefore we cannot directly check the status in

the tunnel, but it seems it is deformed.

Points of through-holes cannot be used

due to the earthquake

⇒MR_01 and MR_05

Displacement of reference points in tunnel

of Hadron beam line

HD-SY : 1.62mm（west）

⇒Did not move largely due to the earthquake

Result of GPS survey（South area of J-PARC）

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DBNC1

KT L1

L01

K TL 2

K TL 3 K T L4

L02

KT L5 K TL 6

KT L7 K TL 8

L03

KT L9 K TL 10

K TL 11

KT L1 2

L04

KT L1 3

K TL 14

K TL 15 K TL 16

L05

K TL 17 K TL 18 KT L1 9 K TL 20 K TL 21 K TL 22 K TL 24 KT L2 3

L06

K TL 25 KT L2 6 K TL 27

L07

K TL 28

K TL 29

K TL 30 K TL 31

L08

K TL 32 K TL 33 KT L3 4 K TL 35

L09

K TL 36 K TL 37

K TL 38 K TL 39

L10

K TL 40 K TL 41 K TL 42 K TL 43

L11

K TL 44

KT L4 5

L12

D400

-3b

(

5.4k

W)

D40

0-3a

D400-4a

(2kW)

D400-4b

(0.6kW)

ANA SLT

(35kW)

ANA BM

ANA DET

(15W)

D400-2

(0.5kW)

R1-1 R1-2 D1-2D1-1

D3-2

S1A S1B S2A S2BS16B M2-1

M2-2ACS1 ACS2 ACS3

ACS4ACS5 ACS6 ACS7 ACS8 ACS9

ACS10ACS11 ACS12

ACS16ACS13

ACS14 ACS15 ACS20ACS18ACS17 ACS19

T1T2

T3

XZ7

T4

XZ8XZ9

ACS21

T5

T6

T7

T9

XZ10

T10

T11

XZ11

T12

XZ12

T13

XZ13

T14

T15

T17

T18

直線部最上流DTL 入口付近(第2ユニットタンク下付近)

SDTL 出口付近ACS 入り口付近

直線部最下

流

460

2000

460

2000

460

2000

460

2000

460

2000

460

2000

460

2000

460

2000

1800

1800

1800

1800

1800

800

1800

1800

15001800

K TL 58

K TL 59

K TL 53

K TL 57

K TL 61

K TL 49

KT L5 1

K TL 52

K TL 60

K TL 75

K TL 66

K TL 67

K TL 68

K TL 69

K TL 70

K TL 71

K TL 72

K TL 73

K TL 74

KT L7 7

K T

L 79

K TL 65

KT L5 4

K TL 62

KT L6 3

KT L6 4

K TL 55

K TL 56

1400

11300

3000

6400

1400

1400

1900

1200

L14

114579 109911

63996

KT L7 6

K TL 80

K TL 78

DB2

DB1S3A

S3B S4A S4BS5A S5B

S6A S6B S7A S7B S8A S8BS9A S9B

S10A S10B S11A S11B S12A S12B S13A S13B S14A S14B S15A S15B S16A

KT L4 6

K TL 47

KT L4 8

KT L5 0

L13NEW

LBP01LBP02 LBP03 LBP04

LBP05LBP06 LBP07 LBP08

LBP09LBP10 LBP11 LBP12 LBP13 LBP14

LBP15

IS/RFQ DTL SDTL （ACS）

First Arc

Co

llim

ato

r

Expansion Joints

Second Arc

330m

Status of Linac

8

Floor settlement after the earthquake

• There are local settlements at the

DTL/SDTL sections (more than 40 mm) and

at the end of the ACS section (about 20

mm).

• The step-like level difference occurred at

the expansion joints.

• There were frequent aftershocks after the

earthquake. Then we continued the level

survey every two weeks.

• The local settlement continued at the

upstream side of the straight section. Most

of the elevation change to this direction

ceased two months later.

Floor elevation change until June

Floor settlement by the earthquake

9

Displacements of the Linac and re-alignment

plan in the straight section

• The dotted line shows the target re-alignment line in the straight section. – The range of the DTL movement is a few millimetres without re-wiring for DTQs. Therefore, aiming at

an early restart of the beam operation, we decided to steer the beam at the steering magnets located downstream of the DTL section horizontally and vertically.

• Longitudinally, the accelerator tunnel was extended about 9 mm at the upstream part of the SDTL section.

– This extension was absorbed smoothly by adjusting the magnets interval at the matching section (about 15m) between SDTL and ACS.

• There is about 25 mm

horizontal displacement

at the straight section.

• Vertical displacement

is consistent to the

floor elevation

10

11

Result after re-alignment of linac straight section

• Relative position after the first arc to the 90

degree dump.

• The beam transport section (from the first arc

to the injection line to RCS) was adjusted to

maintain the proper injection angle and

position to RCS.

Beam transport line (expansion joints)

-2

0

2

4

6

8

10

12

14

320 340 360 380 400 420

Ho

rizo

nta

l p

osi

tio

n [

mm

]

Longitudinal position [mm]

Transverse 0.8mm,

Vertical 1.1mm,

Longitudinal +1.0mm,

Bend 0.3mradTransverse 9mm,

Vertical 3mm,

Longitudinal +1.3mm,

Bend -0.4mrad

1st Arc dump lineCollimator

12

Steered angles of the beam line

MEBT1 exit : 0.33mrad

DTL exit : 0.28mrad

DTL exit : 0.91mrad

1st arc entrance : 0.10mrad

1st arc : 0.15mrad

Exp. joint 1 : 0.03 mrad

Exp. joint 2 : 0.03mrad

2nd arc : 0.27mrad

North to south [mm]

We

st t

o e

ast

[m

m]

He

igh

t [m

m]

Longitudinal position [mm]

Bending magnets are re-aligned and those angles are slightly changed for the connection to RCS.

Vertically steered at the entrance of the 1st arc and expansion joints.

Status of RCS

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Misalignment of RCS magnets before/after the earthquake

Black dots are values taken before and red dots

are values taken after the earthquake.

It was about 3mm displacement to horizontal direction

before the earthquake. Expect for that, displacement

was small.

Horizontal direction moved largely from the extraction

straight section to the injection straight section after

the earthquake.

The amount of displacement was 10mm in a horizontal

direction, 3.7mm in a vertical direction and 5mm in a

longitudinal direction.

Orbit analysis using these results was shown next.

Misalignment caused by the earthquake

15

Solid line shows calculated value and dots shows measured value.

The result of COD survey with 30kW beam

after the earthquake using the parameter of

the steering magnets before the earthquake.

Calculated value and measured value are

nearly the same and it shows COD correction is

possible.

Blue line shows beam loss before and red line shows beam loss after the earthquake.

The effect of misalignment on the beam was surveyed

with the operation condition (300kW and 420kW)

before the earthquake.

At 300kW operation, there was not a big difference in

beam loss before and after the earthquake

but at 420 kW beam loss near the injection collimator

almost doubled, obviously showing the effect of

misalignment.

Influence on Beam operation by misalignment

16

The most difficult part is adjustment of magnets near the injection collimator.

⇒ This area has high radiation dose and workability is very low.

Therefore for realignment it will be adjusted so that adjustment of magnets at the injection

straight section becomes as small as possible.

Displacement expected at this realignment is shown in the figure below.

It was necessary to adjust the magnets about nearly 10 mm in horizontal direction.

However this displacement can be adjusted sufficiently within the range of the magnets

movement.

The realignment of RCS magnets is planned from summer through fall in 2013.

Realignment plane of RCS

17

Status of Main Ring(MR)

18

Horizontal plane

The displacement range was 35 mm horizontal, 13

mm longitudinal and 10 mm vertical direction.

It is seen that the whole beam line showed settlement

of about 2mm.

In addition, magnets from INS-B to INS-C settled down

largely.

Compared to bedrock contour, it is found out that

change of height from QFX099 and QFN162

corresponds to the relief of basement layer.

As there was a large displacement throughout MR,

alignment of the all magnets was implemented from

August through November 2011.

Misalignment caused by the earthquake

Vertical direction

19

Bedrock contour around J-PARC facility

20

When survey data is analyzed, usually through-hole data (6 points) measured by traverse survey

is included.

However this time through-hole data measured by GPS survey was used and among the 2 points

could not be used due to the earthquake. Therefore it was considered that sufficient data accuracy

could not be obtained.

Effect of aftershock was also considered but the levelling data of the floor reference points

implemented before/after the alignment (July and November 2011) showed displacement range of

the tunnel of 0.7mm so it was difficult to think of displacement of several mm in a horizontal

direction.

Survey result after alignment of MR magnets

21

For horizontal direction, displacement of about 8mm occurred regardless of the alignment.

Run27 Shot#19294 (20 Nov 2009) rms: 6.4mmBlue: 30ms, Green:1000ms, Red:2000ms

Run26 Shot#398 (16 Oct 2009) rms: 2.6mmBlue:0ms, Green:300ms, Red:1700ms

Run39 Shot#97 (22 Dec 2011) rms: 2.0mmBlue:0ms, Green:1ms, Red:2ms

Run39 Shot#97 (22 Dec 2011) rms: 1.8mmBlue:0ms, Green:1ms, Red:2ms

Luckily the result of COD measurement without correction after restart of beam operation

was better than that of before the earthquake so it was considered that the alignment status

was good enough.

The final conclusion of MR alignment will be made based on the result of the survey in

summer 2012 carried out after through-holes are recovered.

COD measurement without correction before the earthquake

COD measurement without correction after the earthquake

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Summary

• As the main tunnel of the accelerator facility is held by driving piles into the basement layer

(gravel mudstone layer), GPS survey found smaller displacement in a horizontal direction than

that of reference points on the ground. However deformation in the tunnel and displacement

between facilities were well identified.

• Displacement of the beam line was identified by the survey after earthquake.

Displacement of RCS and MR in a vertical direction corresponded to the relief of basement layer.

• At Beam transport line displacement at expansion joints in a tunnel was large.

• Based on these results, alignment was carried out for all the facilities except for RCS and the

beam operation restarted in December 2011.

• Precise traverse survey of reference points on the ground is being implemented at this moment

and more detailed data is expected to be obtained.

23