DESIGN OF THE SECTOR MAGNET FOR THE IPCR SSC
S. Motonaga, H. Takebe, T. Wada, Y. Yano, J. Fujitaand H. Kamitsubo
The Institute of Physical and Chemical Research
The characteristics of the IPCR SSC are presented in this proceedings;
In order to realize the sector magnets of this sse, the measurements and theanalysis for the magnetic properties have been carried out using two 1/4 scalemodel magnets. The geometrical shape, electromotive force and structure of
the sector magnet are designed. Table 1 lists the parameters of the sectormagnet. The main magnet system of the sse consisits of four sector magnets
with sector angle of sao, gap distance of 8 em and maximum magnetic field oflS.S kG. The maximum magnetic motive force was estimated to be 1.3 x 1aS ampere
turn for the maximum field of lS.S kG. The maximum power consumption of themain coils was estimated to be 4Sa kW. The distance between the outer edgesof the magnets opposite to each other is 12 m. The total weight of this main
magnet system is estimated to be about 23aa tons. The shape of the sector
magnet is shown in Fig. 1. The sector magnet is composed of two poles, a sideyoke and a pair of upper and lower yoke. The upper and lower yoke will bedivided into four or five slabes for the convenience of construction ~nd transportation. The ratio of the cross-sectional area of the pole base to that of
the yoke is l.as. The shape of the pole edge is approximated by the Rogowski
profile so that the effective angle of the sector magnet may not change in therange of magnetic field to be used. The effective angle resulting from model
measurements agrees with the designed value of sao within 1.0°.
The field level and cunfiguration of'the sector magnet-strongly depend on
the iron material. The very homogeneously forged steel with a carbon contentof a.a2 ± a.a1 % were specified for iron material of the poles and the ironmaterial of yoke is a.a8 % carbon forged steel. The two poles of each sector
magnet should be prepared from single ingot. The design of the main coils has
been_ almost completed. They will. be formed> in size of 6 em in thickness and4S em in hight to insert the RF-cavities in the narrows-p-ace between two sector
magnets and will be confined in vacu~ti.ght. stainless st.eel containe.r. The main
coils will be connected in series and excit-ed. with maximum current of. 1100 A~
Maximum.current.de nsi.ty o.f copper ccmduetor .i.s 4. Afmm2_~ The design of the trim
coils has been made on the basis of the results of the calculation and the model
measurements.
The trim coils of the model magnet consist of 14 pairs of copper plates
They have different
Gordon's trajectory.
which have a curved shape ofwidth and pitch, Fig. 2 shows configuration for the modeL The measurementof the radial field distribution was made along the center line of the_ sectormagnet. An example of the measured field distribution in j:he case of y = 1.06
and relative deviations are shown in Fig. 3. Relative values were normalized
to the magnetic field strength at injection radius. The figure show_s comparisonof measured field distribution with 14 trim coil pairs and calculated isochronous field.
The detailed design of the trim coil system for the sector magne.t is nowin progress.

-183-Table 1.

Paramete rs of the sector
magnetNumber of sector magnet

4Sector angle

50°

Gap ,width8 em

Maximum mag.netic field
Maximum ampere turns

l . 3 x 10 5 AT

Pov1er consumpt ion

450 kW

Number of trim coils

30 pairs x 4I

15.5 kG

Trim coil power

400 kW

Injection mean radius

89.3 em

Extractio n mean radius

373 emTotal height

5.2 m

Overall diameter

12.8 mMagnet weight2300 tonIrIl
I

J''-t.;gM

1i-:L::

a1---~l'tw

TI

Fig. 1.

II_lI

Shape of the sector magnet

7B;nj = 10.871 KG

BASEf.

FJELD (10KG)

extract!
2SO350

lJ50

550

550

MODEL RADIUS ( m m Jyg
Y8,.

CURRENTS (A) OF TRIM COILS
9 .,79
3S 33 6~8.784A

No. 135 33

2 3~..§..

ol ~-COl

250

Fig. 2.

Configur ation of the trim
coils for the model magnet

-184-

61

9 <O350

118

7S 99 65 8<7372 105 7885621D7 8

1.22 11 12 1314

73450

75

7501ilil

550

650

750

Fig. 3. Comparis on of measured
field distribu tion with trim
coils excited and isochron ous
field for y= 1.06