HIAT 2009, 9 th June, Venice 1 DESIGN STUDY OF MEDICAL CYCLOTRON SCENT300 Mario Maggiore on behalf...

HIAT 2009, 9th June , Venice 1

DESIGN STUDY OF MEDICAL CYCLOTRON SCENT300

Mario Maggiore

on behalf of R&D Accelerator team

Laboratori Nazionali del SudCatania, Italy


SYNCHROTRONS are today used everywhere (japan, GSI, CNAO) for carbon beam therapy

CYCLOTRONSIBA C235 RESISTIVE COILS

ACCEL\VARIAN K250 SCPROTONS

SC CYCLOTRONIBA C400

INFN SCENT300

PROTONS

CARBON IONS

CYCLOTRONS PROVIDING LIGHT IONS

compactness and simplicity lower size and cost superconducting tech. high beam modulation control fixed energy (ESS needed)



MAIN PARAMETERS


INJECTION LAYOUT

Einj=25 AKeV

Vinflect= 14 KV

gapinflect= 6 mm

Einflect= 23KV/cm

Vdee inj=70 kVBo=3,15 tesla

ECR sources


0 0.5 1 1.5 2 2.5 3 3.5 4-0.5

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0.5

n turns

z [c

m]

CENTRAL REGION DESIGN

Beam centering

Vertical focusing during first turnsEnergy gain

250 AKeV/turn

YC

XC


MAGNETIC FIELD PROPERTIES


10 16 22 28 34 40 46 52 58 64 70 76 82 88 94 100 106 112 118 124 1303 10

4

2 104

1 104

0

1 104

2 104

3 104

ISOCHRONIZATION w/wo -1

R (cm)

0 10 20 30 40 50 60 70 80 90 100 110 120 13010

0

10

20

30

40

70 kV120 kV

PHASE DIAGRAM

R (cm)

DE

G

129.5

UNTIL THE PHASE VARIES WITHIN 20 DEG,

THE MAGNETIC FIELD HAS TO MATCH THE ISOCHRONOUS

ONEWITH A PRECISION OF ±5GAUSS (|ΔB/B|<10-4)

ISOCHRONIZATION LEVEL


RF CAVITY DESIGN

50 kW power losses estimated

fRF = 98 MHz, 4 th harmonic

Emax= 15 MV/m


BEAM DYNAMIC STUDY

structural resonance

coupling resonance


WHAT APPENDS AT RESONANCE ZONE?

Solution?

Jump these radii…

but energy gain

cannot increase

too much

Minimal transverse stability plot


qr 0. 0.1 1.5

1 1.1 1.2 1.3 1.4

0.2

0.4

0.6

0.8

0.5

0.3333

1 1.33333

0 30 60 90 120 150 180 210 240 270 3000.4

0.2

0

0.2

0.4260 292

0 30 60 90 120 150 180 210 240 270 3000.4

0.2

0

0.2

0.4260 292

Radial beam envelop in two cases

old magnetic design

energy energy

cm cm

QrQr


AUTOELLIPSE TRANSPORT

900

1040

910

920

930

940

950

960

970

980

990

1000

1010

1020

1030

PR

R

Number ofturns

24.1 24.2 24.3 24.4 24.5 24.6 24.70.5

0.6

0.7

0.8

0.9

EO3

EO23

EO2

EO22

Ar=0.2

Ar=0.1


60 80 100 1200.3

0.2

0.1

0

0.1

0.2

0.3

radius (cm)

Az

(cm

)

0.3 0.2 0.1 0 0.1 0.2 0.30.3

0.2

0.1

0

0.1

0.2

0.3

Z (cm)

Pz

(cm

)

VERTICAL BEAM DYNAMIC

Vertical beam envelop

Axial space phase


Trimming C12 to H2+: RF and MF change

0 50 100400

200

0

200

dB r( )

r

Bo=cost.

Best solution: coils split into two parts (C400)

RF Frequency scales0,7 %

Two beams mean two differentoperating RF frequencies

small variation of the MFgauss


2nd way: change only the magnetic field

0 50 100 1505 10

3

0

5 103

0.01

0.015

DEISOCHR. C12 vs H2+

RADIUS

fRF = cost

Magnetic field differencebetween C12 and H2+ is larger,but RF freq. is kept constant (it needs only the fine tuning)

0 50 100220

240

260

280

dB r( )

r

gauss


Trimming by two correction coils


0 10 20 30 40 50 60 70 80 90 100 110 120

4

2

0

2

4

FDB i r1 r2 r3( ) DBi

i

GOOD M. FIELD MATCHINGMINIMIZING POWER LOSSES

Less than

4 KW/COIL

MAIN COIL

CC 1CC VALLEY


PHASE SLIP CALCULATED BY EO

0 13 26 39 52 65 78 91 104 117 130200

220

240

260

280

300

dB r( )

Baveh2 r( ) Bave r( )

124

r0 61 122 183 244 305

40

20

0

20

40

EOc1210

EOh210

260

EOc120

EOh20

gamma r( ) interp cspline raggio 1energia

931.494

raggio 1energia

931.494 r

0 13 26 39 52 65 78 91 104 117 1306.8 10

3

6.92 103

7.04 103

7.16 103

7.28 103

7.4 103

7.52 103

7.64 103

7.76 103

7.88 103

8 103

dB R( )

Bave R( )

124

R

MAGNETIC FIELD MATCHING

MAIN COIL : 4586 A/cm2 4586+53.7 A/cm2

CC 1: 104.47 A/cm2 8X8 cm2 , Rint=171 cm, Hmin=81 cm >> 1.32 kW/coil

CC VAL: 395.1 A/cm2 5X4 cm2 , Rint=106 cm, Hmin=69 cm >> 3.24 KW/coilRF SETTING: nu0=24.18717 MHz 24.18587 MHz Δf: 1,3 KHz

TRIMMER RANGE TUNING (~ 6 KHz)

MAIN SETTING TO CHANGE BEAM

12C6+

H2+

extraction


EXTRACTION LAYOUT

VED1,2 = 50kV

Emax = 120kV/cm

4 PASSIVE MCs

ε ~ 60 %protons

Carbon ions

REXT =122 cm

260 AMeV

1 single turn

4 PASSIVE MCs

ε ~ 100 %


BEAM DYNAMIC AT EXTRACTION


CURRENT BEAM ESTIMATION

Protons by stripper

Carbon ions by EDs

Tra

nsm

ission

effi

cien

cy

Ion source 2 mA

Injection line

90 %

Central region

5 % (no buncher)

acceleration

90%

extraction60% C 100% p

P current 80 nA

C current 48 nA


CONCLUSION

The final design of SCENT300 was completed and no other study is expected: the technical drawings of the iron steel are also accomplished out.


GRAZIE !


Coils parameters

Coil Parameters

Size 150x210 mm2

Current density 46.5 amp/mm2

Inner Radius 1420 mm

Distance from the M.P.

70 mm

Energy Stored 35 MJ

Nominal Current (I)

900÷1000 amp

Total current (NI) 1.48 Mamp

Max Magnetic field 4.4 tesla

Axial Force -9.09 MN

Average Hoop Stress (peak)

100 (110) MPa

ConservativeDesign


-745000

-740000

-735000

-730000

-725000

-720000

-715000

0 2 4 6 8 10 12 14

1600000

1610000

1620000

1630000

1640000

1650000

1660000

1670000

1680000

0 2 4 6 8 10 12 14

12

3 4 56

7

891011

12

Vertical force (N)

TOT=-891 tons/coil

Radial force (N)

Average=166 tons/coil

FORCES EVALUATION ON THE COILS (J X B)


1.4 1.45 1.5 1.55 1.695

100

105

110

115

r 0.33( )

MPa

r

1.4 1.45 1.5 1.55 1.65

4

3

2

1

0

1

r r 0.33( )

MPa

r

TENSILE STRESS

STRESS DISTRIBUTION IN THE COILS

1

Rout Rin Rin

Rout

r r 0.33( )

d 101.935MPa

HOOP STRESS

RADIAL STRESS



Summary

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HIAT 2009, 9 th June, Venice 1 DESIGN STUDY OF MEDICAL CYCLOTRON SCENT300 Mario Maggiore on behalf...

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