04 Hadron Accelerators

A12 FFAG, Cyclotrons

Paper Title Page
MOPEA022 PAMELA: Lattice Solution for a Medical C6+ Therapy Facility 115
 
  • S.L. Sheehy, K.J. Peach, H. Witte, T. Yokoi
    JAI, Oxford
  • D.J. Kelliher, S. Machida
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
 
 

PAMELA (Particle Accelerator for MEdicaL Applications) employs novel non-scaling Fixed Field Alternating Gradient (NS-FFAG) technology in the development of a proton and C6+ particle therapy facility. One of the challenges of this design is the acceleration of high energy C6+ in a lattice which enables high flexibility and reliability for treatments, yet remains minimal in size and complexity. Discussed here is the Carbon 6+ lattice solution in terms of both design and performance.

 
MOPEB035 Present Status of the RCNP Cyclotron Facility 349
 
  • K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, K. Nagayama, H. Okamura, T. Saito, H. Tamura, T. Yorita
    RCNP, Osaka
 
 

The RCNP accelerator cascade consists of an injector Azimuthally Varying Field (AVF) cyclotron (K=140) and a ring cyclotron (K=400). It provides ultra-high-quality beams and moderately high-intensity beams for a wide range of research in nuclear physics, fundamental physics, applications, and interdisciplinary fields. The maximum energy of protons and heavy ions are 400 and 100 MeV/u, respectively. Experimental apparatuses are used like a pair spectrometer, a neutron time of flight facility with a 100 m long tunnel, a radioactive nuclei separator, a super-thermal ultra cold neutron (UCN) source, a white neutron source, and a RI production system for nuclear chemistry. Such ultra high resolution measurements as dE/E = 5x10-5 are routinely performed with the Grand-Raiden spectrometer by utilizing the dispersion matching technique. The UCN density was observed to be 15 UCN/cm3 at the experimental port at a beam power of 400 W. Some topics on the research are discussed in the talk.

 
MOPEC038 Commissioning of FFAG Accelerator at Kyushu University 543
 
  • T. Fujinaka, T. Matsunaga, S. Mochizuki, H. Takase
    Kyushu University, Center for Accelerator and Beam Applied Science, Fukuoka
  • H. Arima, T. Hasuo, N. Ikeda, K. Ishibashi, T. Korenaga, K. Maehata, N. Shigyo, Y. Uozumi, G. Wakabayashi, Y. Yonemura
    Kyushu University, Department of Applied Quantum Physics and Nuclear Engineering, Fukuoka
  • K. Fujita, T. Morikawa, T. Noro, T. Wakasa
    Kyushu University, Fukuoka
  • Y. Mori
    KURRI, Osaka
  • H. Nakayama, A. Takagi
    KEK, Ibaraki
  • T. Tomimasu
    SAGA, Tosu
 
 

150 MeV FFAG accelerator is under construction at Center for Accelerator and Beam Applied Science on Ito Campus to promote activities in all related scientific, medical, engineering and educational field at Kyushu University. In this paper, status of the development of hardware and the results of the beam commissioning of the injector are described.

 
MOPEC039 Developments for Beam Intensity Increase and Beam Quality Improvement in the RCNP Cyclotrons 546
 
  • M. Fukuda, K. Hatanaka, H. Kawamata, M. Kibayashi, T. Saito, H. Tamura, T. Yorita
    RCNP, Osaka
 
 

An upgrade program of the RCNP cyclotron facility for increase of beam intensity and improvement of beam quality is in progress to meet requirements from research in nuclear physics and industrial applications using secondarily produced particles such as neutrons, muons and radioisotopes. A 2.45 GHz ECR ion source using a set of permanent magnets was developed for high intensity proton beam production. The proton beam intensity more than 0.5 mA at an extraction energy of 15 keV has been obtained with a proton ratio more than 80 %. The quality of the pre-accelerated beam from the K140 injector AVF cyclotron has been improved by a flat-top(FT) acceleration system to enhance the beam transmission to the K400 ring cyclotron. Transversal resonant mode of a dee electrode with a span angle of 180 degrees was investigated to achieve the FT acceleration in the frequency region from 50 to 60 MHz. In this paper, developments for high intensity proton beam acceleration and beam quality improvement using the FT acceleration system of the AVF cyclotron will be mainly presented.

 
MOPEC041 Calculation of Second Order Moments for an Ion Beam in a Degrader 549
 
  • N.Yu. Kazarinov, V.I. Kazacha
    JINR, Dubna, Moscow Region
 
 

In order to decrease the energy of an ion accelerated in a cyclotron on value of some MeV/eau it is possible to run an ion beam through a thin metal foil (degrader). One can calculate the final ion energy, angular and energy stragglings, which the beam attains in the degrader, for example, by means of code LISE++. The formulae for calculation of the beam second order moments after degrader were obtained. The formulae for calculation of final beam momentum spread, new values of rms beam emittances, Twiss parameters and the dispersion functions were also obtained. The new ion beam parameters allow one to calculate the beam transportation along the beam line after degrader.

 
MOPEC042 Synchrocyclotron Preliminary Design for a Dual Hadrontherapy Center 552
 
  • A. Garonna
    EPFL, Lausanne
  • A. Garonna
    TERA, Novara
 
 

Hadrontherapy, the technique of tumor radiotherapy employing heavy ion beams, is developing rapidly(*). The TERA Foundation proposes an innovative dedicated accelerator, called Cyclinac(**). It is composed of a 230 MeV/u cyclotron providing fast pulsed beams of H2+, for proton therapy with standard techniques, or C6+, injected into a high gradient linac. Its energy can thus be modulated from pulse to pulse (up to 400 MeV/u), for optimal irradiation of solid tumors with the most modern techniques of dose active spreading. A preliminary design of a superconducting synchrocyclotron for this application is presented. Its advantages are the reduced construction and operating costs (small magnet and low RF power consumption), and the good adaptation of its beam characteristics to therapy (low current and fast repetition rate). The magnet features a central field of 5 T, which has azimuthal symmetry and decreases with the radius, ensuring radial and vertical focusing. The weight is around 300 t. Ions are produced in an EBIS, injected axially and resonantly extracted at 1 m radius. The RF is mechanically modulated by a rotating capacitor, providing the required 400 Hz repetition rate.


* U. Amaldi, G. Kraft, J.Rad. Res., 48 Suppl A (2007) 27
** U. Amaldi, S. Braccini, P. Puggioni, Reviews of Accelerator Science and Technology, Vol.2 (2009)

 
MOPEC043 Error Study of a Novel Non-linear, Nonscaling FFAG 555
 
  • D.J. Kelliher, S. Machida
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
  • S.L. Sheehy
    JAI, Oxford
 
 

A novel nonlinear, nonscaling FFAG ring has been designed for proton and ion acceleration [1]. It can be used for proton and carbon therapy as well as a proton driver for various facilities such as a high intensity neutrino factory. The machine has novel features including variable energy extraction and a high repetition rate of about 1 kHz. Taking as an example the PAMELA proton ring, under study at the John Adams Institute in Oxford, we present results of an error study. A calculation of alignment tolerance is made, in which the effects of translational misalignments of the triplet magnets are included. The effect of misalignments on the dynamic aperture of the machine is investigated.


[1] S. L. Sheehy, K. J. Peach, H. Witte, D. J. Kelliher and S. Machida, Phys. Rev. ST Accel. Beams, 13 (2010) 040101

 
MOPEC044 A Fixed Field Alternating Gradient Accelerator With Long Straight Sections 558
 
  • S. Machida
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
 
 

The lattice of a Fixed Field Alternating Gradient (FFAG) accelerator normally has high symmetry. The whole ring consists of many identical cells which have a simple FODO, double or triplet focusing unit. There is, however, no real reason for an FFAG lattice to have high symmetry, except for a linear nonscaling design which relies on high symmetry to avoid betatron resonances. We propose an FFAG lattice design with a superperiod that makes it possible to have long straight sections for injection, extraction and rf cavities. We discuss how to introduce a superperiod structure. The impact on dynamic aperture, dispersion function, longitudinal dynamics as well as the advantage of having long straight sections will be presented.

 
MOPEC046 Modelling of the EMMA ns-FFAG Injection Line using GPT 561
 
  • R.T.P. D'Arcy
    UCL, London
  • D.J. Holder, B.D. Muratori
    Cockcroft Institute, Warrington, Cheshire
  • J.K. Jones
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
 
 

EMMA (Electron Machine with Many Applications) is a prototype non-scaling Fixed Field Alternating Gradient (NS-FFAG) accelerator presently under construction at Daresbury Laboratory, UK. The energy recovery linac ALICE will serve as an injector for EMMA within the energy range of 10 to 20 MeV. The injection line consists of a symmetric 30° dogleg to extract the beam from ALICE, a matching section and a tomography section for transverse emittance measurements. This is followed by a transport section to the injection point of the EMMA ring. Commissioning of the EMMA injection line started in early 2010. A number of different injection energy and bunch charge regimes are planned; for some of the regimes the effects of space charge will be significant. It is therefore necessary to model the electron beam transport in this line using a code capable of both calculating the effect of, and compensating for, space charge. Therefore the General Particle Tracer (GPT) code has been used. A range of injection beam parameters have been modelled for comparison with experimental results.

 
MOPEC047 High Current Proton FFAG Accelerators 564
 
  • R.J. Barlow, A.M. Toader, S.C. Tygier
    UMAN, Manchester
 
 

Accelerator Driven Subcritical Reactors require a high currents of energetic protons. We compute the limits imposed by space charge, and explore what can be achieved using various proposed FFAG lattices. Limitations due to beam losses and reliability are also discussed

 
MOPEC048 Beam Extraction of PAMELA NS-FFAG 567
 
  • T. Yokoi, K.J. Peach, H. Witte
    JAI, Oxford
 
 

PAMELA (Particle Accelerator for MEdicaL Application) aims to design a particle therapy facility using Non-scaling FFAG (Fixed Field Alternating Gradient) accelerator. In the beam extraction in PAMELA, the biggest challenge is the flexible energy variability, which is desirable for better dose field formation. The feature is a unique feature of PAMELA for a fixed field accelerator. To realize energy variable beam extraction, PAMELA employs vertical extraction using large a aperture kicker magnet. In the paper, the detail of the extraction scheme, hardware specifications are discussed.