NIRS. Outline HIMAC. Introduction Gantry developments. Superconducting magnets Construction of gantry structure. Future project.

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1 Yoshiyuki Iwata National Institutes for Quantum and Radiological Science and Technology (QST), National Institute of Radiological Sciences () 2016/11/25

2 Outline Introduction Gantry developments Superconducting magnets Construction of gantry structure Future project Summary 2

3 Carbon radiotherapy Heavy Ion Medical Accelerator in Chiba () Ion species: p ~ Xe E/A=800 MeV for q/m=1/2 Cancer treatments using energetic carbon ions since 1994 Successful clinical results >10000 patients Linacs (RFQ+Alvarez DTL) Ion sources (ECRx2, PIG) Treatment rooms (3 rooms) Synchrotron rings 3

4 New treatment facility Construction completed in FY treatment rooms Room E & F Fixed H&V scanning ports (in treatment operation) Room G Rotating gantry port (Under commissioning) 4

5 Treatment floor (B2F) Room G CT Simulation room accelerators Room E & F

6 Superconducting rotating-gantry Use of superconducting (SC) magnets Ion kind : 12 C Irradiation method: 3D Scanning Beam energy : 430 MeV/n Maximum range : 30 cm in water Beam orbit radius : 5.45 m Length : 13 m Weight: order of 300 tons The size and weight are considerably reduced 6

7 Layout of the SC gantry Scanning magnets on top Large scan size Combined function SC magnets No quadrupole magnet required BM06 BM05 BM08 BM07 BM04 BM09 BM10 ISO-CENTER 13m ST02 PRN02 Combined function SC magnets Square irradiation field Parallel beam BM03 BM02 BM01 7

8 Development of superconducting magnets 8

9 Curved SC magnets for gantry SC magnet (BM02-05) Cross-sectional view 4K Cryocoolers (SHI RDK-415D) Liquid He free! Dipole and quadrupole coils can be independently excited 9

10 Cooling of SC magnets 4K GM compact cryocoolers Liquid He free Rotatable Cooling plates Cryocoolers Thermal shields & Current leads SC coils Beam duct Heat penetration SHI cryocooler (RDK-415D) 10

11 Z (cm) Superconducting coil design Dipole(26 layers) + Quadrupole (8 layers) X (cm) 11

12 Surface-winding coil structure Superconducting NbTi wires are wound on surface of a curved mandrel. Superconducting wires (NbTi) Superconducting coil 12

13 ΔBzL/BzL 3D field calculation with Opera-3d SC coils were precisely modelled 1.0E E E E E E E E ΔX (m) Curved SC coil DBL/BL <

14 Z (cm) ΔBzL/BzL Corrections with the outermost layer Coil positions of the outermost layer were modified to cancel out the measured multi-pole components Corrected uniformity E E E E E E E E E ΔX (m) X (cm) DBL/BL <1 10-4! 14

15 Design of SC magnets All the SC magnets were designed by using a 3D magnetic field solver 15

16 BM04 (26deg) Construction of SC magnets BM10 (22.5deg) 16

17 Fast slewing tests Tests with maximum slew-rate I=45~136 A (E=56~430 MeV/u) No quench observed Average temperature converged below Tc~6.6 K s (db/dt=0.038 T/s) 6.5 s (db/dt=0.3 T/s) Current Pattern Time (seconds) BM Time (seconds) 17

18 Construction of the gantry structure 18

19 Construction of structure 19

20 Assembly at Toshiba 20

21 Rotation tests at Toshiba 21

22 Transportation to 22

23 Reassembling at Construction completed by the end of September

24 Treatment room Room G 24

25 Superconducting gantry 25

26 Beam tests 26

27 Beam tests begun since Oct. 2015

28 1 σ b ea m siz e [m m ] Beam tuning (1) Angular dependence of a beam size and shape at the isocenter (E=430 MeV/u) deg 135 deg 90 deg 67.5 deg 45 deg σx σy deg 0 deg -45deg -90deg -135deg G a n try a n g le [d eg ]

29 DI/I QM (%) 1s beam size (mm) Beam tuning (2) The superconducting quadrupoles were tuned so as to obtain circular beam spots (E=430 MeV/u) BM deg 135 deg 90 deg 67.5 deg 45 deg BM BM deg 0 deg -45deg -90deg -135deg BM10 ISO-CENTER BM08 2.0% 1.0% 0.0% -1.0% BM07 QM4 QM5-2.0% Gantry angle (deg) PRN ST02 σx BM04 σy BM03 BM02 BM Gantry angle (deg)

30 Beam tuning (3) Beam tuning was made for various beam energies (E=430~55.6 MeV/u) MeV/u 387 MeV/u 292 MeV/u 2.5 σx σy 238 MeV/u 174 MeV/u 55.6 MeV/u 1σ beam size at Iso [mm] E [MeV/u]

31 Future plan 31

32 Ultra compact rotating gantry(1) High-field superconducting magnets B max =5 Tesla 45 m Betatron amplitude functions [m] versus distance [m] m Dispersion functions [m] versus distance [m] m m -2.5 m Horizontal Vertical

33 Ultra compact rotating gantry(2) Size and weight are less than those of proton gantries

34 SC Synchrotron SC magnets (Dipole+Quadrupole) B max ~ 5 [T] db/dt~ 1+ [T/sec] Circumference~21 [m] 34

35 Summary Development of the superconducting rotating-gantry Compact Construction was completed by the end of Sep Commissioning is in progress Future plan Treatment will be planned since April 2017 Ultra-compact gantry and SC synchrotron are being designed

36 Collaborators K. Noda, T. Shirai, T. Fujita, S. Sato, T. Furukawa, K. Mizushima, Y. Hara, R. Tansho, Y. Saraya, N. Saotome () T. Fujimoto, H. Arai (AEC) T. Orikasa, S. Takayama,, S. Matsuda Y. Nagamoto (Toshiba) T. Ogitsu (KEK) T. Obana (NIFS) N. Amemiya (Kyoto Univ.) 36

37

38 Specifications of SC magnets Parameters Symbol Unit BM01 BM02 BM03 BM04 BM05 BM06 BM07 BM08 BM09 BM10 Type - - Superconducting sector magnet Coil - - Dipole+Quard. Dipole Dipole+Quard. Bending angle q deg Bending radius r m Maximum field B dipole T Maximum field gradient G max T/m Bore size D bore mm f Effective radius or area D f or A f mm f Uniformity (dipole) ΔBL/BL - ± Uniformity (quadrupole) ΔGL/GL - ± Inductance (dipole) L H Stored Energy (dipole) P kj

39 Multiple-flattop operation Operation pattern having multiple flattops Each flattop can be extended Beams having various energies can be extracted! Extended flattop 1000 Output beam ms ms ms

40 Full energy scanning Beam energy is varied by 1 or 2 mm step in water range E= MeV/u 202-flattop pattern No energy degrader Scanning magnets Ridge filter Energy degrader 40

41 Beta and dispersion functions Beam optics design Beam envelope functions with kicks of scanning magnets 25.0 m 150mm Beam duct BM1 BM2 BM3 BM4 BM5 BM6 BM7 BM8 BM9 BM m BM1 BM2 BM3 BM4 BM5 BM6 BM7 BM8 BM9 BM m -150mm mm SCM-X SCM-Y 20.3m BM1 BM2 BM3 BM4 BM5 BM6 BM7 BM8 BM9 BM m m -150mm m 41

42 Fine tuning of QM04, QM05 Generating pattern file BM06 BM05 BM08 BM07 BM04 BM09 BM10 ISO-CENTER ST02 PRN02 BM03 BM02 BM01

43 Tuning with Steering magnets Centering beam spots BM06 BM05 BM08 BM07 BM04 BM09 BM10 ISO-CENTER ST02 PRN02 BM03 BM02 BM01