A new 3-axes magnetic field measurement system based on the Hall - - PowerPoint PPT Presentation

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A new 3-axes magnetic field measurement system based on the Hall - - PowerPoint PPT Presentation

Jan 20, 2023 222 likes •364 views

A new 3-axes magnetic field measurement system based on the Hall elements E. Hirose, K. H. Tanaka, T. Takahashi, Y.Satou, K. Agari, M. Ieiri, Y. Kato, M. Minakawa, H. Noumi, Y. Sato, Y. Suzuki, H. Takahashi, M. Takasaki, A. Toyoda, Y. Yamada

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SLIDE 1

A new 3-axes magnetic field measurement system based on the Hall elements

  • E. Hirose, K. H. Tanaka, T. Takahashi, Y.Satou,
  • K. Agari, M. Ieiri, Y. Kato, M. Minakawa, H.

Noumi, Y. Sato, Y. Suzuki, H. Takahashi, M. Takasaki, A. Toyoda, Y. Yamada and Y. Yamanoi KEK Beam Channel Group TOKIN Corporation

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SLIDE 2

3 m 1.2m Bore:200mm

The typical magnet for 50GeV transfer line

Weight : ～40ton

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SLIDE 3

The new 3-axes magnetic field measurement system

The Base Plate The Auto-level unit The rod The Control unit 3-axes Hall probe The mechanics for moving rod The Magnet

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SLIDE 4

The Base Plate

The base plate supports prepared on the floor, which were fixed by anchor bolts. Pivots fitting on the base 7m long 2m wide iron base. The base level stability is within 0.1mm against the magnet weight 40 ton.

2m 7m

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SLIDE 5

The rod

10.1 7.2 4.4 1.8 2200 3.8 2.4 1.0 1700 1.9 0.7 1200 The rod length [mm] 2200 1700 1200 700 Measuring position from the part of support [mm] Quantity of deflection [mm]

2200 10.1

Material : carbon fiber composite Diameter : 20mm Thickness : 2mm The weight of Hall probe : < 50g

2200

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SLIDE 6

The Hall Sensor unit

Vz Vy Vx

Flexible polyimide base film 16-pin connector The measured temperature coefficient of Hall elements :

  • 0.075%/degree

A PEEK block Heater Nichrome coil Cover with marked the positions

1-axis Hall elements : National OH008

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SLIDE 7

The angler resolution of a 3-axes Hall probe

  • 2
  • 1

. 5

  • 1
  • .

5 . 5 1 1 . 5 2 5 1 1 5 2 2 5 3 3 5 R

  • t

a t i n g a n g l e [ d e g r e e ] H a l l v

  • l

t a g e [ V ] V x V y V z

Θy = 180.92 Θx = 91.35 Measured angle between X and Y Hall elements : 89’34’’

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SLIDE 8

Operating the Hall elements and data taking

  • Current supply

– Operating current : 6mA – Stability : +-0.02%

  • Temperature controller

– 60℃+-0.01 – The error by temperature : about 0.15mTesla for 2Tesla

  • Heater power supply
  • Switching digital

voltmeter

– Hall voltage of each axis – Current of Magnet power supply – Interfaced to the PC via GP-IB

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SLIDE 9

The mechanics for moving rod

Y : ±500 X : ±500 Z : 0～+2000 The control unit

  • They moved by servo motors via PCI motor control board
  • The accuracy of the positions : within 0.1mm
  • The rod can be moved through the axis step by step
  • The motion speed is controlled to be slow start/slow stop manner
  • interval distance=5mm (movement time:2.3sec, waiting time for stopping the

rod oscillation :1sec)

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SLIDE 10

Adjusting the rod axis and magnet axis

Remote control unit and Auto- level unit

Starting point Magnet axis Another point

Given the starting point and another point on the magnet axis, the field measurement points on the magnet coordinate can automatically be calculated and positioned in software way.

The rod

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SLIDE 11

The operating monitor

Hall Voltage Position Power supply Date Filename Define the starting point Define the final point Waiting time Interval distance > 1mm

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SLIDE 12

Calibration

  • A dipole magnet (max flux

density = 2.2Tesla) was used for calibration of Hall probe

  • Absolute flux density was

measured be NMR at the same time

  • The error of fitting is estimated

within 3 Gauss at whole measurement range.

y = 5 . 9 2 3 1 2 E

  • 3

x

6
  • 3

. 7 8 5 9 E

  • 2

x

5

+ 8 . 7 9 3 6 3 E

  • 2

x

4
  • 9

. 7 1 3 3 E

  • 2

x

3

+ 4 . 7 7 1 4 E

  • 2

x

2

+ 1 . 1 4 7 7 3 E + x

  • 4

. 9 9 6 1 E

  • 3

. 5 1 1 . 5 2 2 . 5 . 5 1 1 . 5 2 Y H a l l V

  • l

t a g e [ V ] M a g n e t i c F l u x D e n s i t y [ T e s l a ]

y = 3 . 2 6 5 4 E

  • 3

x

6
  • 1

. 7 7 5 4 4 E

  • 2

x

5

+ 3 . 6 7 4 2 E

  • 2

x

4
  • 3

. 2 8 3 9 E

  • 2

x

3

+ 1 . 2 4 4 9 E

  • 2

x

2

+ 1 . 1 7 7 7 E + x

  • 7

. 9 6 5 2 9 E

  • 3

. 5 1 1 . 5 2 2 . 5 . 5 1 1 . 5 2 X H a l l V

  • l

t a g e [ V ] M a g n e t i c F l u x D e n s i t y [ T e s l a ]

y = 4 . 8 5 2 4 1 E

  • 3

x

6
  • 2

. 9 3 1 6 6 E

  • 2

x

5

+ 6 . 8 6 4 9 2 E

  • 2

x

4
  • 7

. 6 3 5 2 E

  • 2

x

3

+ 3 . 7 9 6 4 1 E

  • 2

x

2

+ 1 . 1 5 1 2 E + x

  • 5

. 1 8 9 3 E

  • 3

. 5 1 1 . 5 2 2 . 5 . 5 1 1 . 5 2 H a l l V

  • l

t a g e [ V ] M a g n e t i c F l u x D e n s i t y [ T e s l a ]

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SLIDE 13

Conclusion

  • A new 3-axes magnetic field measurement system based on

the Hall elements has been constructed at KEK

  • We can align the measuring machine and the magnet at the

accuracy within 0.1 in total be simply putting the magnet on the base

  • The field measurement points on the magnet coordinates can

automatically be calculated and positioned in software way

  • 3 Hall elements could be mounted in one sensor unit and the

angle between X and Y Hall elements is 89’34’’

  • The temperature of Hall elements can be controlled within 60

+-0.1 degree

  • The deflection of rod was less than 10mm for 2200 mm

carbon rod length

  • We have successfully measured the field of the Q-magnet,

whose bore diameter and length are 200mm and 3m