GANIL RF systems : feedback control system and electronics

http://accelconf.web.cern.ch/AccelConf/c81/papers/ep-10.pdfInternational audienc

The test bench for the power amplifiers of the SPIRAL-2 SC LINAC

International audienceThe high current driver accelerator of the SPIRAL 2 project uses independently phased SC resonators working at 88 MHz. Solid state power amplifiers equipped with circulators are foreseen to drive the cavities with widely ranging conditions of beam loading. These power devices are developed by industrial companies and a test bench has been studied and manufactured to test the prototypes, to commission all the units before their installation on the accelerator and to be used to test repaired modules. Even if designed to be used at 88 MHz, the test bench can be used at higher frequencies too. The poster describes the test bench as well as the results on the first amplifiers bought for the cryomodule power tests

Improvement of the mass separation power of a cyclotron by using the vertical selection method

International audienceIt is well known that cyclotrons are very good mass separators, specially when the number of turns in the machine is large. This property is particularly interesting if the cyclotron unavoidably accelerates multiple species of radioactive beams simultaneously, which is the case for the cyclotron CIME at GANIL. We propose to improve the natural mass separation power by using a vertical resonance effect: it consists of putting two small electrodes between the poles, which provide a vertical electric field operating at two frequencies close to twice the RF frequency and which are tuned with respect to the vertical betatron oscillation. A prototype has been designed and built at GANIL, and tested successfully in the cyclotron CIME this September

Preliminary design of the RF systems for the SPIRAL2 LINAC

International audienceIn the SPIRAL 2 Linac, a 5 mA, CW, Deuteron beam is accelerated up to 40 MeV, through a normal conducting (NC) RFQ and 26 independent-phase superconducting (SC) quarter wave resonators, working at 88.05 MHz. Tube and solid state amplifiers derived from the standard FM transmitter modules are foreseen while a new digital control system is being designed for the feed-back and feed-forward amplitude and phase control.. The paper presents the power and low level systems for both the NC and SC cavities and results of simulations of the RF system in operating conditions

Control electronics for the CIME RF system

International audienceThe paper describes the characteristics of the amplitude and phase loops for the accelerating voltage, thecontrol system which manages securities, sparks and multipactor problems for the cavities. Design methods andresults during first power tests are presented

THI safety system

International audienceFor several years, GANIL has been allowed to reach a maximum beam power of six kilowatts (400W in normal mode) thanks to the THI system (High Intensity Transport System). Three modes of running are necessary to accelerate a THI beam ("Injector" mode, "tuning" mode and "surveillance" mode). The "surveillance" mode requires a safety system to protect equipment against beam losses. Inside cyclotrons, diagnostics measure beam-loss currents at the injection and extraction devices. Along beam lines, diaphragms measure beam-loss currents at the input and output of dipoles. Current transformers are used for beam transmission measurements through beam lines and the cyclotrons. The safety system controls beam losses and quickly cuts the beam with a chopper if losses exceed thresholds. These thresholds can be seen and changed by software

Injector Diagnostics Overview of SPIRAL2 Accelerator

International audienceThe SPIRAL2 project is based on a multi-beam driver in order to allow both ISOL and low-energy in-flight techniques to produce Radioactive Ion beams (RIB). A superconducting light/heavy-ion linac capable of accelerating 5 mA deuterons up to 40 MeV and 1 mA ions up to 14.5 MeV/u is used to bombard both thick and thin targets. These beams could be used for the production of intense RIB by several reaction mechanisms (fusion, fission, transfer, etc.). The post acceleration of RIB in the SPIRAL2 project is assured by the existing CIME cyclotron. SPIRAL2 beams, both before and after acceleration, can be used in the present experimental area of GANIL. The construction phase of SPIRAL2 is being started since the 1st of July 2005. An injector design overview is presented with diagnostics used to tune and qualify beams

Beam Intensity and Energy Control for the SPIRAL2 Facility

TUPB029 - ISBN 878-3-95450-122-9International audienceThe first part of the SPIRAL2 facility, which entered last year in the construction phase at GANIL in France, consists of an ion source, a deuteron and a proton source, a RFQ and a superconducting linear accelerator delivering high intensities, up to 5 mA and 40 MeV for the deuteron beams. Diagnostic developments have been done to control both beam intensity and energy by non-interceptive methods at the linac exit. The beam current is measured by using couples of ACCT-DCCT installed along the lines and the beam energy by using a time of flight device. This paper gives explanations about the technical solutions, the results and resolutions for measuring and controlling the beam

Intensity Control in GANIL's Experimental Rooms

TUPF31International audienceThe safety re-examination of existing GANIL facilities requires the implementation of a safety system which makes a control of the beam intensity sent to the experimental rooms possible. The aim is to demonstrate that beam intensities stay below the authorized limits defined by the safety GANIL group. The challenge is to be able to measure by a non-interceptive method a wide range of beam intensities from 5nA to 5 A with a maximum uncertainty of 5%, independently of the frequency (from 7 to 14.5MHz) and the beam energy (from 1.2 to 95MeV.A). After a comparative study, two types of high frequency diagnostics were selected, the capacitive pick-up and the fast current transformer. This paper presents the signal simulations from diagnostics with different beam energies, the uncertainty calculations and the results of the first tests with beam

Recent developments for beam intensity increase operation

International audienceThe aim of the beam intensity increase operation (THI project) is to multiply the present intensities for lightest ions by a factor of fifteen in order to reach maximum power of six kilowatts [1]. The main objective is the production of large amounts of rare isotopes, either with SISSI (device intended for producing radioactive beams), or with SPIRAL (production and acceleration of radioactive ion beams). As part of this THI project, new developments have been required such as spiral scanners, for beanl profile measurements, and safety system to protect equipments against beam losses. Other developments are being carried on to improve the high intensity beam operation