Beam dynamics for cyclotrons

This paper intends to introduce the beam dynamics in the cyclotron. The long history of the cyclotron evolution is reminded and the different developments since 1929 from E. Lawrence’s great idea are reviewed from conventional cyclotron to synchrocyclotron. The transverse and longitudinal beam dynamics are detailed as well as the specific quantities applied to cyclotron. Finally, and since the study of the dynamics in cyclotrons differs from the one in synchrotrons due to the non-periodic lattice, an opening to beam dynamics computation is proposed to handle the peculiar way of cyclotron tuning. A list of books, articles and proceedings is referred to the end to go deeper in the subjec

GANIL Status report

The GANIL-Spiral facility (Caen, France) is dedicated to the acceleration of heavy ion beams for nuclear physics, atomic physics, radiobiology and material irradiation. The production of radioactive ion beams for nuclear physics studies represents the main part of the activity. The facility possesses a versatile combination of equipments, which permits to produce accelerated radioactive ion beams with two complementary methods: Isotope Separation In Line (ISOL) and In-Flight Separation techniques (IFS). Considering the future of GANIL, SPIRAL II projects aims to produce high intensity secondary beams, by fission induced with a 5 mA deuteron beam on an uranium target.Comment: 5 pages, 5 figures, to be appear in the proceedings of the 17th International Conference on Cyclotrons and their Application

Operation status of High Intensity Ion Beams at GANIL

International audienceThe GANIL facility (Caen, France) is dedicated to the acceleration of heavy ion beams for nuclear physics, atomic physics, radiobiology and material irradiation. The production of stable and radioactive ion beams for nuclear physics studies represents the main part of the activity. Two complementary methods are used for exotic beam production: the Isotope Separation On-Line (ISOL, the SPIRAL1 facility) and the In- Flight Separation techniques (IFS). SPIRAL1, the ISOL facilty, is running since 2001, producing and post-accelerating radioactive ion beams. The running modes of the accelerators will be recalled as well as a review of the operation from 2001 to 2008. A point will be done on the way we managed the high intensity ion beam transport issues and constraints which allows the exotic beam production improvement

Nulling Emittance Measurement Technique for CLIC Test Facility

In order to test the principle of Two-Beam-Acceleration (TBA), the CLIC Test Facility utilizes a high-intensity drive beam of 640 to 1000 nC to generate 30 GHz accelerating fields. To ensure that the beam is transported efficiently, a robust measurement of beam emittance and Twiss parameters is required. This is accomplished by measuring the beam size on a profile monitor, while scanning five or more upstream quadrupoles in such a fashion that the Twiss parameters at the profile monitor remain constant while the phase advance through the beam line changes. In this way the beam size can be sampled at different phases while a near-constant size is of such measurement devices, especially those associated with limited dynamic range. In addition, the beam size is explicitly constant for a matched beam, which provides a ``nulling'' measurement of the match. Details of the technique, simulations, and results of the measurements are discussed

Emittance Growth during Bunch Compression in the CTF-II

Measurements of the beam emittance during bunch compression in the CLIC Test Facility (CTF-II) are described. The measurements were made with different beam charges and different energy correlations versus the bunch compressor settings which were varied from no compression through the point of full compression and to over-compression. Significant increases in the beam emittance were observed with the maximum emittance occuring near the point of full (maximal) compression. Finally, evaluation of possible emittance dilution mechanisms indicate that coherent synchrotron radiation was the most likely cause

Bunch Compressor Performances at the CLIC Test Facility

The Test Facility of the "Compact Linear Collider" (CLIC) at CERN (CTF), has to prove the feasibility of transporting high charge beams through decelerating structures at 30 GHz to create RF power. This RF power is used to supply, in the final scheme, the cavities of the main linac. To optimise this power generation, a bunch compressor has been installed in the test line. This compressor shortens the electron bunches after creation and acceleration in the RF gun. The compressed bunches are then accelerated by a high gradient cavity (50 MV/m) and transported to a 30 GHz cavity. Compressed bunch length mesurements showed that lengths of 0.6 mm (rms) were obtained at the entrance of 30 GHz cavity for a 10 nC beam. Compression of electron bunches of charges between 2 and 17 nC have also been measured. Emittance measurements were done to study the transverse effects of the bunch compressor on the beam. The use of the code PARMELA allowed the design and optimisation of the chicane. The simulations results have been compared to the experimental measurements