For the Facility for Antiproton and Ion Research (FAIR) a compact proton linac will produce proton beams with energy of 68 MeV that will be injected into upgraded Heavy Ion Synchrotron (SIS 18), accelerated to 4 GeV, and further accelerated to 30 GeV in SIS 100. The commissioning of the proton injector which would serve for the injection into the proton linac has already started at CEA/Saclay. The ion source operating with a microwave frequency of 2.45 GHz based on Electron Cyclotron Resonance (ECR) plasma production with two coils each with 87.5 mT magnetic field, will deliver a 100 mA proton beam at 95 keV of energy. The Low Energy Beam Transport (LEBT) including two short solenoids system and integrated steerers will transport the proton beam to the RFQ entrance with an expected emittance lower than 0.37E min mrad (normalized, nns). After the LEBT an electrostatic chopper will be mounted in front of RFQ to shorten the beam pulse to 36 mu s. This paper presents the status of the commissioning phases including first results of proton injector.

The high current ion source with the low energy beam transport (LEBT) will serve as injector into the proton LINAC to provide primary proton beam for the production of antiprotons. The pulsed ion source developed and built in CEA/Saclay operates with a frequency of 2.45 GHz based on ECR plasma production with two coils with 87.5 mT magnetic field necessary for the electron cyclotron resonance. The compact LEBT consists of two solenoids with a maximum magnetic field of 500 mT including two integrated magnetic steerers to adjust the horizontal and vertical beam positions. The total length of the compact LEBT is 2.3 m and was made as short as possible to reduced emittance growth along the beam line. To measure ion beam intensity behind the pentode extraction system, between solenoids and at the end of the beam line, two current transformers and a Faraday cup are installed. To get information about the beam quality and position, the diagnostic chamber with different equipment will be installed between the two solenoids. This article reports the current status of the proton injector for the facility of antiproton and ion research.

Experiments to investigate the space charge compensation of pulsed high-current heavy ion beams are performed at the GSI ion source text benches with a 4-grid analyzer provided by CEA/Saclay. The technical design of the 4-grid analyzer is revised to verify its functionality for measurements at pulsed high-current heavy ion beams. The experimental investigation of space charge compensation processes is needed to increase the performance and quality of current and future accelerator facilities. Measurements are performed directly downstream a triode extraction system mounted to a multi-cusp ion source at a high-current test bench as well as downstream the post-acceleration system of the high-current test injector (HOSTI) with ion energies up to 120 keV/u for helium and argon. At HOSTI, a cold or hot reflex discharge ion source is used to change the conditions for the measurements. The measurements were performed with helium, argon, and xenon and are presented. Results from measurements with single aperture extraction systems are shown.

The microwave ion source and the low energy beam transport section (LEBT) developed in a joint FrenchGerman collaboration (CEA/Saclay – GSI/Darmstadt) will serve as an injector for the compact proton LINAC for FAIR [1]. The microwave ion source is presented in Fig.1. The ion source will be located on the platform with a potential of 100 kV inside the special cage (Faraday cage). This ion source operates in pulsed mode with a frequency of 2.45 GHz. RF power is provided by a magnetron (microwave generator) and injected into the plasma chamber. The plasma chamber has a length of 10 cm and the diameter of 9 cm.

The new international accelerator facility for antiproton and ion research (FAIR) at GSI in Darmstadt, Germany, is one of the largest research projects worldwide and will provide an antiproton production rate of 7 × 10(10) cooled pbars per hour. This is equivalent to a primary proton beam current of 2 × 10(16) protons per hour. For this request a high intensity proton linac (p-linac) will be built with an operating rf-frequency of 325 MHz to accelerate a 35 mA proton beam at 70 MeV, using conducting crossed-bar H-cavities. The repetition rate is 4 Hz with beam pulse length of 36 μs. The microwave ion source and low energy beam transport developed within a joint French-German collaboration GSI/CEA-SACLAY will serve as an injector of the compact proton linac. The 2.45 GHz ion source allows high brightness ion beams at an energy of 95 keV and will deliver a proton beam current of 100 mA at the entrance of the radio frequency quadrupole (RFQ) within an acceptance of 0.3π mm mrad (norm., rms).

FAIR - the international facility for antiproton and ion research – located at GSI in Darmstadt, Germany is one of the largest research projects worldwide. It will provide an antiproton production rate of 7·10 10 cooled pbars per hour, which is equivalent to a primary proton beam current of 2·10 16 protons per hour. A high intensity proton linac (p-linac) will be built, with an operating rffrequency of 325 MHz to accelerate a 70 mA proton beam up to 70 MeV, using conducting crossed-bar H-cavities. The repetition rate is 4 Hz with an ion beam pulse length of 36 µs [1]. Developed within a joint French-German collaboration - GSI/CEA-SACLAY/IAP – the compact proton linac will be injected by a microwave ion source and a low energy beam transport (LEBT). The 2.45 GHz ion source allows high brightness ion beams at an energy of 95 keV and will deliver a proton beam current of 100 mA at the entrance of the RFQ (Radio Frequency Quadrupole) within an emittance of 0.3π mm mrad (rms). To check on these parameters computer simulations with TraceWin, IGUN and IBSIMU of the ion extraction and LEBT (Low Energy Beam Transport) are performed.

The microwave ion source and low energy beam transport (LEBT) for the injection into the proton linac have to deliver a 100 mA proton beam with an energy of 95 keV at the entrance of the RFQ within an acceptance of 0.3π mm mrad (normalized rms). The source SILHI (high intensity light ion source) at CEA/Saclay meets these requirements. It operates with a frequency of 3 GHz and allows high brightness ion beams with energies up to 100 keV and full beam currents of 130 mA [1]. The proton injector for the FAIR facility is presented in Fig.1. The microwave ion source runs in a pulsed mode by pulsing the rf generator. The RF power is produced by a magnetron and injected into the source via standard rectangular wave guides. The duty cycle is 4 Hz with a pulse length of 0.2 ms. The minimum pulse duration is 300 μs with a 100 μs rise and fall time. The source is able to run with a long time of operation (several months) with good performance as noise to beam fluctuation ≤5 % and pulseto-pulse repetition ≤2.5 %.

The 4-grid Analyzer, or Retarding Potential Analyzer (RPA) is dedicated to space charge compensation measurements of ion beams by analyzing the energy distribution of secondary ions accelerated by the beam potential. The RPA consists of four grids, as shown in Figure 1. Grid one is on ground potential to shield the ion beam. Grid two repels electrons coming from the beam tube. The voltage on grid 3 is retarding and can be varied from negative to positive electric potential to filter secondary ions produc ed during interaction between primary ions and residual gas in the beam. The fourth grid repels electrons produced in the Faraday cup at the end of the RPA. For capturing the signal a current to voltage transformer (I-U transformer) with a high signal acceptance is used.