The FAIR facility will provide intense primary beams of protons and heavy ions, or secondary beams of antiprotons and rare isotopes. The operation includes fixed-target experiments or subsequent facilities of independent storage rings and experiment beam lines. The particle beams greatly differ in ion species, energy, intensity, time structure, spot size and stopping power. Therefore, transverse beam profile measurements require a careful choice of detector type for each location in order to cope with the large dynamic range and operational demands. This contribution presents the actual status of FAIR detector developments for intercepting devices (SEM-grids, multi-wire proportional chambers, scintillating screens) as well as non-intercepting beam induced fluorescence monitors and ionization profile monitors. Recently, promising results were obtained with an 11.4 MeV/u Uranium beam in measurements of optical transmission radiation emitted from thin metal foils. The boundaries for the application area are described and basic detector parameters are summarized. FAIR BEAM PARAMETERS The main objectives of the upcoming FAIR (Facility for Antiproton and Ion Research) accelerator complex are to provide high-intensity ion beams, to generate beams of rare isotopes, as well as the production and storage of anti-protons [1]. Because the existing GSI accelerators Unilac and SIS18 will serve as injectors for FAIR a longterm upgrade program had been initiated including an extensive upgrade of beam diagnostic devices for the requirements of high-intensity operation. The foreseen FAIR standard operation modes require e.g. that Unilac routinely injects 510 U in a 150 μs macropulse into SIS18 as a booster synchrotron. From SIS18 the beam will be injected into the fast ramped superconducting heavy-ion synchrotron SIS100, the main accelerator of the future FAIR complex. SIS100 will deliver high-energy high-intensity protonand heavy ion beams near the space charge limit. The requirements for the experiments with radioactive ion beams include acceleration of up to 410 U ions/s to end energies of 400-2700 MeV/u, either in single bunches of 30-90 ns, or as slowly extracted beam with extraction times of several seconds. For the production of anti-protons 2.510 protons per pulse will be accelerated to 29 GeV with a repetition rate of 0.1 Hz and an output bunch length of 50 ns. It is clear that the large variety of beam parameters along the FAIR accelerator chain requests for well-matched diagnostic devices. Moreover, the high-energy beam transport lines (HEBT) have to be designed for the transport of ion beams with a large range of parameters. Because of the multiplexed experiment operation, the beams principally might differ on a pulse-by-pulse manner in ion species, energy, intensity, time structure and transverse beam width. The interconnection of the existing SIS18 to SIS100 has a magnetic rigidity of 18 Tm and will transport slowly and fast extracted beams in the intensity range 110310 particles per pulse. Beams to and from the storage rings will be transported by 13 Tm and 100 Tm beam lines, but also here a large range of beam intensities of 10-10 particles per pulse is planned. Additionally, the aperture has a range of 100-150 mm, which sets up additional requirements with regard to the mechanical layout of beam profile monitors. INSTRUMENTATION FOR BEAM PROFILING For the broad range of parameters adequate instruments for beam profile detection have been developed at GSI in the past years. Devices are divided into intercepting instruments, like SEM-grid, multi-wire proportional chamber (MWPC) or scintillating screens (SCR), that are specifically used for beam optimization procedures and non-intercepting devices, like beam induced fluorescence monitors (BIF) or ionization profile monitors (IPM) that allow for online profile measurements. Table 1: Typical Parameters during Test Measurements for Development of FAIR Instrumentation Device Ion Energy [MeV/u] Detection Threshold [Part./Pulse] Spatial Resol. [mm] SEMGrid U 11.4 510 <1

Trapping of particles in nonlinear resonances in the presence of space charge and synchrotron motion may be a source of beam halo generation and beam loss in high intensity synchrotrons, in particular for extended storage times at the injection plateau as planned for the SIS100 synchrotron of the FAIR project. Although extensive simulation studies have theoretically demonstrated this mechanism, experimental evidence was so far limited to demonstration experiments at the CERN Proton Synchrotron (PS) in 20022003 using an octupolar resonance. Here we describe new experiments at the SIS18 synchrotron at GSI, where the resonance is driven by a sextupolar field error and horizontal static tune scans are taken across the resonance stop band. The new data significantly extend the previous observations by a complete set of measurements comparing beams with and without rf, both at low and high intensity. The correlation between transverse beam loss and simultaneous bunch length shortening provides strong evidence that the measured emittance and the loss in intensity are indeed caused by periodic resonance crossing, leading to the main effect of scattering but also to a lesser extent to the trapping of particles due to the combined effect of the nonlinear resonance and the space charge.

The prediction of beam loss for long term storage of a high intensity beam is a challenging task essential for the SIS100 design. On this ground an experimental campaign using a high intensity beam has been performed at GSI on the SIS18 synchrotron with the purpose of extending a previous benchmarking experiment made at the CERN-PS in the years 2002-2003. We report here the results of this experimental campaign and the benchmarking with the simulation predictions.

As conventional intercepting diagnostics will not withstand high intensity ion beams, Beam Induced Fluorescence (BIF) profile monitors constitute a preeminent alternative for non-intercepting profile measurements [1]. This diagnostic technique makes use of the optical fluorescence emission of beam-excited gases. Recently BIF became an important diagnostic tool for transversal beam profile measurements with applicability in beam tuning over a wide range of beams and accelerator conditions [2]. In this paper optical VISspectroscopy with an imaging spectrograph for 5 MeV/u proton, S and Ta beams in nitrogen, Xe, Kr, Ar, Ne and He at 10 mbar gas pressure is presented. Atomic physics processes are a major performance issue, since they determine transition intensities and lifetimes of excited states. Further investigations are required to improve the detector performance and increase its range of application.

The advanced ionization beam profile monitor is being developed at GSI for the future FAIR facility in collaboration with ITEP and FZ-Jülich. In January 2009 the IPM prototype was installed in COSY-Jülich. After successful hardware test the beam tests followed. The prototype was operated without magnetic field, thus only residual gas ions were detected. An arrangement consisting of an MCP stack, a phosphor screen, and a CCD camera was used to detect ions. We report the first profile measurements of the proton beam up to 2.8 GeV at COSY.

The FAIR (Facility for Antiproton and Ion Research) accelerator complex is currently designed and projected at GSI. The unique features of the main machine SIS100, like e.g. the acceleration of high intensity beams of 2.5×10 protons and 5×10 Uranium ions, the operation close to the space charge limit leading to a large tune spread and the extreme UHV conditions of the cryogenic system for fast ramped superconducting magnets, impose challenging demands on the beam diagnostic components. This contribution describes the general concept of beam diagnostics for FAIR and reports on the present status of prototype studies. Exemplarily the achievements for a novel type of dc transformer, beam position monitors and the ionization profile monitor are discussed and first measurements with prototype setups are presented. FAIR ACCELERATOR COMPLEX Presently GSI entered the final planning phase for the international FAIR project [1]. The existing GSI accelerators, UNILAC and SIS18, together with a new high-current proton LINAC will act as injectors. In its final stage FAIR will consist of two heavy ion synchrotrons (SIS100, SIS300) and four storage rings (CR, RESR, NESR, HESR). The main features of FAIR are: acceleration of all ion species from protons to Uranium, high currents of primary beams, generation of radioactive beams for fixed target experiments or injection in storage rings, as well as antiproton production, accumulation and storage ring experiments. For the planned large variety of physical experiments the multiplexed operation of the whole facility with different settings for ion species, energy etc. on a pulse-to-pulse basis, has been an important design criterion. In this contribution we focus on diagnostics for the fast ramped superconducting synchrotron SIS100 and the high energy beam transport section of FAIR. REQUIREMENTS FOR DIAGNOSTICS A set of general strategies has been considered in order to facilitate the construction of the facility with worldunique complexity. A main paradigm is the facility-wide standardization of diagnostic devices. Even though the requirements of the synchrotrons and storage rings differ, it is planned to use identical diagnostic installations wherever applicable. Standardization also covers the front-end software FESA [2] as an integrative platform for all diagnostic devices at FAIR. Concerning the hardware it is planned to use commercially available components to a maximum extent, in order to reduce manpower and spares inventory. FAIR beam parameters impose strict requirements for all diagnostic devices. A strong constraint with regard to mechanics is the extreme UHV condition down to 5×10 mbar in SIS100. In this main synchrotron, high currents (up to the space charge limit) of primary beams in low charge states will be stored and accelerated with a large incoherent tune spread of up to ΔQ≈0.5. An important prerequisite is the precise beam alignment since in certain locations the synchrotron acceptance is limited to 6 times the rms beam width. For the High Energy Beam Transport section of FAIR the acceptance is even lower, four times the rms beam width. The goal for diagnostics in transport lines and storage rings is to achieve a high resolution and low detection limit. Additionally, the HEBT diagnostic devices have to deal with slow and fast extracted beams, respectively. Due to the requirement for online measurements and in order to prevent device destruction at high beam intensities, non-intercepting diagnostics is preferred and focused on in this contribution. BEAM CURRENT MEASUREMENT Novel DC Current Transformer (NDCCT) For the GSI-built synchrotron DCCT, it was found that at high beam currents (>70mA) and bunch frequencies around 1.2 MHz the feedback loop of the DCCT loses control and the setting of the correct working point becomes unreliable. Therefore an alternative device based on state-of-the-art sensor technology is presently under development at GSI [3]. The NDCCT makes use of integrated GMR sensors (giant magneto-resistance) inside the gap of a split flux concentrator (amorphous alloy or ferrite toroid). The GMR signals are corrected and amplified by a differential pre-amplifier. Additionally, an AC transformer path is implemented by a secondary winding. Special requirements for the NDCCT are: low noise characteristic, high resolution (~100 μA), capability to measure beam currents from 100 μA to 150 A (2 A DC), bunch frequency up to 5 MHz, long-term zero-point stability and high absolute accuracy. The utilized GMR sensor (AA-0002, Nonvolatile Electronics Co.) consists of 4 meandered resistors and 2 flux concentrators, building up a Wheatstone bridge. Studies on the frequency response revealed that the sensor circuitry spans inductive loops and, above a certain threshold frequency, the frequency response of the GMR sensor becomes disturbed. The upper frequency threshold was found to be a result of macroscopic effects like unwanted induced voltages in the sensor, eddy currents and skin effects in the GMR's NiFe-layer, leading to a reduced bridge voltage above the cut-off frequency of 1 MHz, as depicted in Fig. 1. The GMR frequency response is shown for different core materials (CMD5005, ___________________________________________ *Work partly supported by EU-FP6 DIRAC-phase1, -secondary-Beams WEOA04 Proceedings of DIPAC09, Basel, Switzerland 01 Overview and Commissioning

A new multi-channel counting module for advanced Ionization Profile Monitor applications has been developed. The module maximal performance concerning time resolution is about 10 beam profile measurements per microsecond at the cost of a slightly reduced spatial resolution with 80% accuracy (or better). Module architecture, basic modes of operation and the user interface are discussed. The results of first laboratory tests are also presented. IPM AND BIF BEAM PROFILE REGISTRATION METHODS There is a class of methods which use very few residual gas molecules as a probe matter for non destructive beam profile detection. Fig. 1 shows schematically the operation of residual gas ionisation profile monitor (IPM)[1] on top and beam induced fluorescence (BIF) on the bottom. Figure 1: Principles of residual gas beam profile measurements. The IPM principle of operation is on top and BIF monitor on bottom. Electrons or photons are casually emitted in collisions between accelerated beam particles and residual gas molecules. Properly guided they can be detected by position sensitive elements. Traditionally high resolution CCD devices are used as detectors. However these high spatial resolution devices can not be used for investigation of fast processes which are for instance a subject of interest during beam extraction or injection. To put new features into residual gas profile monitors, fast detectors like SiPMs or tube photomultipliers can be used in parallel with CCD cameras. In [2] one can find a consideration of using avalanche photodiodes in connection with fast photocurrent amplifiers for IPM systems. The factor which gives the preference to the photomultipliers and discriminators is an expected rate of collision events which is more suited for a counting mode. Some features of fast operation modes also have been discussed in [2]. When using a CCD camera as a detector a signal amplification is required to get enough photons on the light sensitive matrix. In the case of IPM such amplification is provided by a MCP-phosphor assembly placed close to the beam, while the BIF monitors use an image intensifier in the near of a CCD matrix. For a fast profile detector which is operating in parallel to the classical CCD this means different operation modes: true single photon registration in the case of BIF and photon cluster detection in the case of IPM. No hardware modification is required to switch between these modes. STRUCTURE OF THE MODULE The module layout is shown on Fig. 2. The small dimensions, enforced case and minimal connection requirements allow to install the counting module outside of electronics room close to the light detector itself. Figure 2: Picture of the multichannel counting module. Initially it was assumed that this module will operate in combination with multichannel photomultiplier tubes (PMT) or silicon photomultiplier (SiPM) array – detectors which are producing output pulses with similar timing and amplitude parameters. Both types of detectors can be connected either over moderate length 50 Ohm transmission line bundles or directly onto amplifiers input. In most cases the detectors output pulse timing parameters are sufficient for 5ns double pulse recognition (see Fig. 5). More detailed the module structure is shown on Fig. 3. It includes 32 discriminator lines, an FPGA for fast online data processing and buffering, a powerful 32 bit ARM-based microcontroller and Ethernet controller as a basic communication standard for a host computer connection. The counting module also includes a high TUPC060 Proceedings of EPAC08, Genoa, Italy 06 Instrumentation, Controls, Feedback & Operational Aspects 1194 T03 Beam Diagnostics and Instrumentation voltage power supply required for PMT operation. An optional digital processor module can be connected over the high performance 32-bit bus or by using several channels of a fast serial interface. Figure 3: The internal structure of the counting module. Each of the analog paths includes an amplifier (AD8009), a low-pass filter for noise reduction and a fast comparator with differential output (ADCM604). The signal amplification allows to use a lower relative threshold level. Due to the high sensitivity of the electronics a long cable bundle can be used to move the counting module out of the radiation hard conditions.

We describe the first results of an extensive experimental campaign, called S317, performed at GSI in the SIS18 synchrotron. High intensity effects on the beam during one second storage after injection are examined using the available transverse and longitudinal beam profile diagnostics. A first discussion of the results in comparison with the CERN-PS experiment is outlined.

The upgrade of the SIS18 to become the injector of the SIS100 requires beam loss control/limitation at the percent level [1]. The storage of high intensity beams needs careful choice of the working point and of compensation of the resonances crossing the beam space charge tune spread (as large as ∆Q ∼ 0.5). However, the linear coupling may be useful for balancing beam emittances and improving multiturn efficiency. The study of the SIS18 resonances was carried out in a measurement campaign in 2004-2005 with low intensity beams. The correlation between beam loss

For most beam parameters the stored current is monitored by a commercially available dc-transformer offering a dynamic range from 1 μA to 20 A maximum. Its bandwidth of 10 kHz allows determination of the beam lifetime with ms time resolution. But it is known, that these types of transformers have severe problems by a high current bunched beam passage [1]. Even though an improved version is available, no test with beams has been performed so far and scalability from other machines might be doubtful due to the resonance nature of the severe distortion. Therefore investigations of a different type of sensitive magnetic field sensor in collaboration with the University Kassel (Germany) have been started. The idea consists in taking the scheme of a clamp-on ammeter and using a high-effective magnetic sensor in the core gap. Usually Hall-sensors are installed in such measurement devices, but due to the larger core diameter needed in beam diagnostics and the high dynamics of the beam currents to be monitored other sensors have to be investigated like AMR (Anisotrope MagnetoResistance), GMR (Giant MagnetoResistance) or GMI (Giant MagnetoImpendance) and tailored for this application [2]. The scheme of such a device and a first simulation of the magnetic flux concentrator are shown in Fig. 1. First results show that the GMI effect would be the most interesting candidate for the sensor, but no commercial element is available until today [3]. For GMR the situation looks better [4] and the further development will concentrate on this sensor type.

Beam profile measurements at modem ion synchrotrons and storage rings require high timing performances on a turn-by-turn basis. High spatial resolutions are essential for cold beams and beamwidth measurings. The currently used RGM supported very interesting measurements and applications. Due to the readout technology the spatial and time resolution is limited. To meet the expanded demands a more comprehensive device is under development. It will be an all-purpose residual gas monitor to cover the wide range of beam currents and transversal particle distributions. Due to the fast profile detection it will operate on primary electrons after residual gas ionization. A magnetic field of 100 mT binds them to the ionization point inside 0.1-mm orbits. The high-resolution mode will be read out by a digital CCD camera with an upstream MCP-phosphor screen assembly. It is planned to read out the fast turn-by-turn mode by an array of 100 photodiodes with a resolution of 1 mm. Every photodiode is equipped with an amplifier-digitizer device providing a frame rate of similar to10 MSamples/s.

The beam profile measurements at modern ion synchrotrons and storage rings require high timing performances on a turn-by-turn basis. On the other hand, high spatial resolutions are very desirable for cooled beams. We are developing a residual gas monitor to cover the wide range of beam intensities and dimensions. It supplies the needed high-resolution and high-speed tools for beam profiling. The new residual gas monitor will operate on secondary electrons whose trajectories are localized within 0.1 mm filaments. The required magnetic field of 100 mT will be excited by either a permanent or an electromagnet. The high resolution mode of 0.1 mm is provided by a CCD camera with upstream MCP-phosphor screen assembly. In the fast turn-by-turn mode the beam profile will be read out with a resolution of 1 mm by a 100-channel photodiode-amplifier-digitizer, which will be explained in detail.