Technical Design Report Super Fragment Separator

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DRAFT The expected radiation hardness of CVD diamond is the most important material property initiating the research and development of diamond detectors. For the tracking of minimum ionizing particles (mip) in the LHC experiments ATLAS and CMS [25] as well as for a variety of heavy ion applications with high luminosity beams [26] diamond detectors have been already developed. In the case of mips no increase in leakage current and unchanged collected charge is obtained for all kind of particles up to a fluence of about 10 15 particles/cm². However, the heavy ion dose which starts damaging CVD diamond is still unknown. Currently as a lower limit about 10 13 cm –2 , 12 C ions (at 1-2 GeV/u) and 131 Xe ions that were even stopped in the detector material have been already applied without any degradation of these detectors. According to the fragment distribution as shown in Figure 2.4.104 we would expect an intensity of 10 12 uranium ions per spill on a (10 x 20) mm² area which corresponds to an annual dose of 10 18 /cm 2 /y. Our calculations have shown that the material as such will survive such intensities; the question to be investigated is now whether a thin detector film can stand such a dose without getting blind. The beam catcher detector arrays would then have an active area of (40 x 20) cm² build from the cheapest poly crystalline as grown CVD-D material. They will be freely movable over the full aperture of the Pre-Separator. A spatial resolution of about 1mm is considered to be ideal for monitoring the fragment distributions. It has been already demonstrated, that the readout electronics can be safely placed about 1m away from the detector system without degradation of the electronic signals. However, a detailed study has to be performed how to build a 600-channel readout and cabling for these detectors. 2.4.6.2 Diagnostics for slowly extracted beams We define slow extraction as extraction times that are above 100ms for the Super-FRS. Beam diagnostics systems will be installed in all intermediate foci PF(0-4), MF(1-12) with a standardized active area of (40 x 20) cm² whenever possible (at MF11 (90 x 20) cm² will be needed for the LEB). Two systems will be placed at PF(0, 2, 4) and MF(1-12) to allow an angular measurement. At intensities above 1 nA in the Pre-Separator, beam induced fluorescence (see section 2.4.6.1) has to be used. If the energy deposit/mm stays below 100 mW current grids [27] are routinely used to measure beam profiles. At even lower intensities (< 100 kHz) usually multiwire chambers or gems [28] with single wire or single pad front-end readout boards will be used to measure beam particles event-by-event, thus allowing tracking through the separator (see also section 2.4.6.5). This standard instrumentation is chosen for its moderate system cost. Whenever possible a continuous recording of the beam positions will be done to allow automatic steering of the beam to the nominal position. Additional standard tracking detectors, presently operating at the FRS, are the Time Projection Chamber (TPC). The high efficiency at 100-200 kHz (see Figure 2.4.84) allow them to be used as in-beam detectors for experiments using slow-extraction beams, Available drift volumes are (20 x 6,8,10) cm 2 . They are filled with a P10 gas mixture at 1 bar pressure. Using a standard VME readout (see Figure 2.4.84), reading two x-position and 4 y-position measurements, σx=0.1 and σy=0.05 mm can be achieved, respectively. Such detectors are ideal for precise momentum-measurements experiments. 86
DRAFT Figure 2.4.84: Left panel: TPC detector and associated electronic scheme. Right panel: TPC efficiency measured for 129 Xe beam at 500 MeV/u as a function of the particle rate. In this case (momentum measurement) the detector is working as position-sensitive detector recording single ions. The readout can be improved to reach a dead-time free readout speed of 160 kHz/wire by making use of the CBM-XYTER ASIC and readout boards. These boards are based on the N-XYTER [29] ASIC for the DETNI project, and are being currently developed at GSI. 2.4.6.3 Diagnostics for fast extraction For fast extraction mode and intensities above 1 nA capacitive pickups [30] are routinely used to deduce the beam position. We will use these pickups for the Pre-Separator of the Super-FRS. The usual current grids and multi wire chambers (see section 2.4.6.2) can be used to measure fast extracted beams at lower intensities. For beams with a spill length as short as 50 ns, single ion tracking is no longer feasible, and only measurements of the bunch profile can be performed. This problem arises from the large amount of charge (up to several nC) which is deposited in the detector. The use of a gas detector leads to a long integration time for complete charge collection (~ µs). This causes a spreading of the charge and thus strongly affects the measurement of the beam profile. Therefore the use of fast electronics and lower gas pressure has been proposed. Recent investigations have shown that it is advantageous to operate the gas filled current grids at reduced pressure or even without gas for fast extracted beams. The gas supply system for the relevant detector systems should therefore provide gas mixtures at reduced pressure down to 1 mbar. A Beam Profile Detector (BPD) prototype using a variable gas pressure and delay-line read-out was developed in collaboration with the University of Bratislava within the NUSTAR 3 task of the FP6 EU Design Study for the Super-FRS facility. It was successfully tested in November 2007 at the FRS with fast extracted carbon beams at the highest intensities (several 10 9 ion/spill) from SIS18. On-line measurements showed excellent stability of the response (beam profile in both x and y) with still considerable reserves for even higher beam intensities. The detector has a modular design with a basic module size of (100x100) mm 2 . In Figure 2.4.85 (left panel) a BPD of (200x100) mm 2 active area made by two basic modules is shown together with the front-end electronics. The detector volume is filled with a gas of Ar + 10 % CO2. It contains 3 x 50 wires. Each wire with 2 mm pitch is directly connected to 3 integrated passive delay lines for x and y position measurements. The integrated electronics containing pre-amplifiers, amplifiers and zero crosser worked reliably. The digitalization of the fast signal was obtained by using a Flash ADC 87
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DRAFT Technical Design Report Super
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Preface DRAFT The International Fac
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Contents DRAFT 2.4.1 System Design
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DRAFT Table 2.4.1: Parameters of th
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DRAFT degrader stage which provides
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Pre-Separator DRAFT In order to acc
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DRAFT coupling coefficients is give
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DRAFT Table 2.4.3: First-order matr
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DRAFT Main-Separator to the high-en
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DRAFT Table 2.4.5: Transmission T o
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DRAFT Figure 2.4.15: Resolution nec
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DRAFT Figure 2.4.17: Spectrometer m
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DRAFT Table 2.4.8: Design parameter
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DRAFT Figure 2.4.20: Side view of t
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DRAFT Figure 2.4.23: Coil cross-sec
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DRAFT Figure 2.4.25: Flux density d
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Figure 2.4.29: Assembly of two half
Page 35 and 36: DRAFT Figure 2.4.31: Cross section
Page 37 and 38: Figure 2.4.34: Sketch of the therma
Page 39 and 40: DRAFT To fulfill the required field
Page 41 and 42: DRAFT Figure 2.4.39: The 3D model o
Page 43 and 44: DRAFT Pole radius mm 100 210 250 25
Page 45 and 46: DRAFT Figure 2.4.43: Front, side, a
Page 47 and 48: ∆B/B 0.0 DRAFT Figure 2.4.46: Ave
Page 49 and 50: DRAFT Figure 2.4.50: 3D model of th
Page 51 and 52: DRAFT Figure 2.4.54 and Table 2.4.1
Page 53 and 54: DRAFT 2.4.2.3.1 Radiation resistant
Page 55 and 56: DRAFT The water-cooled radiator con
Page 57 and 58: DRAFT Table 2.4.17: Coil parameters
Page 59 and 60: DRAFT Figure 2.4.63: Field distribu
Page 61 and 62: DRAFT Figure 2.4.65: Multiplet conf
Page 63 and 64: DRAFT Table 2.4.21 summarizes the r
Page 65 and 66: 2.4.2.6 Current Leads DRAFT The cur
Page 67 and 68: DRAFT Table 2.4.23 presents the lis
Page 69 and 70: 2.4.3 Power Converters DRAFT The po
Page 71 and 72: SCR structure DRAFT Regarding high
Page 73 and 74: a) Chopper circuit 3x400V b) Half b
Page 75 and 76: External Control System Data transf
Page 77 and 78: DRAFT Figure 2.4.77: Arrangement of
Page 79 and 80: SuperFRS Power Supply Effective App
Page 81 and 82: DRAFT The locations for the differe
Page 83 and 84: DRAFT Figure 2.4.80: Beam induced f
Page 85: DRAFT Figure 2.4.82: Two hybrids ca
Page 89 and 90: DRAFT extracted beams. Its use for
Page 91 and 92: Time of Flight measurement DRAFT At
Page 93 and 94: DRAFT together. Another option is t
Page 95 and 96: DRAFT Figure 2.4.88: Pillow seal po
Page 97 and 98: DRAFT Figure 2.4.90: Setup at the m
Page 99 and 100: DRAFT An overview of the total vacu
Page 101 and 102: 2.4.7.4 Appendix - Technical Drawin
Page 103 and 104: DRAFT Figure 2.4.96: Diagnostic cha
Page 105 and 106: DRAFT Figure 2.4.98: Diagnostic cha
Page 107 and 108: DRAFT Figure 2.4.100: Diagnostic ch
Page 109 and 110: 2.4.8 Particles Sources n/a 2.4.9 E
Page 111 and 112: DRAFT movable, but BC3 must be able
Page 113 and 114: DRAFT Figure 2.4.106: Spot size of
Page 115 and 116: dE/dV [kJ/cm 3 ] 3 2 1 DRAFT includ
Page 117 and 118: 2.4.11.1.4 Design of the beam catch
Page 119 and 120: DRAFT Figure 2.4.110: Calculated eq
Page 121 and 122: DRAFT Figure 2.4.112: Location of b
Page 123 and 124: DRAFT the carbon. Again mainly 7 Be
Page 125 and 126: DRAFT maintenance of the carbon or
Page 127 and 128: DRAFT material) and received the an
Page 129 and 130: DRAFT commissioned in February 2005
Page 131 and 132: DRAFT Table 2.4.28: Typical beam pa
Page 133 and 134: DRAFT Figure 2.4.120: Surface tempe
Page 135 and 136: DRAFT Figure 2.4.123: Schematic lay
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DRAFT These results show that the i
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DRAFT Like in the case of the rotat
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DRAFT Figure 2.4.126: Left: Schemat
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DRAFT Figure 2.4.128: Schematic lay
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DRAFT Figure 2.4.129: Flow scheme o
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DRAFT Since the weight of the cold
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DRAFT With the cooling capacity spe
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DRAFT Figure 2.4.134: Schematic of
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S1 (a) Figure 2.4.136: (a) Zoom of
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2.4.A Appendix DRAFT The appendix o
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DRAFT experiment the EXL community
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2.4.A1.3 Slow control and monitorin
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DRAFT Figure 2.4.139: Architecture
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DRAFT all FAIR accelerators will be
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DRAFT source tier are split in two
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DRAFT coupled from the ACS which is
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DRAFT 2.4.A3.2 Work packages: descr
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2.4.A3.2.4 Instrumentation Measurin
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DRAFT this, planning a network layo
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DRAFT 2.4.A3.3 Machine characterist
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DRAFT installation of RALF was done
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DRAFT The double ring synchrotrons,
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DRAFT The first refrigerator, Cryo1
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DRAFT shield 28874 + 25 g/s 22 bar
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LHe storage Helium storage Helium s
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Cryo2 Cryo3 CryoST DB 3 DRAFT Compr
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DRAFT The cold connection will be m
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DRAFT Measurements planned for each
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DRAFT For magnets with less stringe
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DRAFT The value, parameters, condit
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DRAFT 3. Geometry tests For cryosta
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DRAFT The Quench Heaters Tests has
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DRAFT Figure 2.4.159: Photograph of
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DRAFT The field properties listed i
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DRAFT Figure 2.4.161: Schematic vie
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DRAFT Figure 2.4.162: Scheme of the
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2.4.A6.2.2 Shielding against direct
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DRAFT Figure 2.4.164: Schematic lay
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DRAFT Figure 2.4.165: An iron beam
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DRAFT In a side view the flux of pr
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DRAFT catcher 7 Be, 22 Na and 24 Na
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DRAFT at the FRS (2·10 9 /spill as
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DRAFT [1] H. Geissel et al., Nucl.
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DRAFT [74] A. Fabich and J. Lettry,
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Technical Design Report Super Fragment Separator

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