Technical Design Report Super Fragment Separator

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DRAFT radiation shielding in the limited space of the separator. All materials should be good heat conductors. The entrance material should be low in mass number (A) to avoid too high temperatures. This can already be seen from the simple formula below for the temperature rise (∆T) due to a number of particles (N) characterized by a stopping power dE/d(ρx), a beam spot area σ 2 , and a molar heat capacity (Cmol), which for high temperatures becomes a constant defined by Avogadro's number (NA)and Boltzmann's constant (kB). dE / d( ρx) A ∆T = N ; Cmol = 3N Ak 2 B σ C mol for high As dE/d(ρx) only moderately changes for different A and Z of the stopping materials, low A is clearly preferable. Energy deposition in different materials Besides the beam spot size the density of the deposited energy also depends on the amount of nuclear reactions of the primary beam. Simulations with the codes FLUKA [43,44] and PHITS [41] were performed to study the energy deposition taking into account both nuclear and atomic interactions and the contributions of the secondary beam. An example for 10 12 Uranium at 740 MeV/u dumped in carbon with a round Gaussian beam spot with σ = 1 cm is shown in Figure 2.4.107. In this calculation the initial energy spread was assumed to be zero. Without fragmentation the ratio of the stopping power at the entrance and in the Bragg peak would be 6.9 [45]. However, nuclear reactions reduce this ratio to 3.1. In Li and Be the nuclear reaction rate is higher compared to the energy-loss cross section. Therefore, the Bragg peak would be reduced by an even larger factor. Values are listed in Table 2.4.25. The same conclusions hold for higher initial energies. The density of energy deposition in the bulk material can also be reduced by geometrical shaping of the entrance of the beam catcher such that the range straggling is enhanced. In the example of Figure 2.4.107 the ratio of the peak to entrance energy deposition has been reduced to about 1.8 with an inclined surface of a slope of 0.1. In Table 2.4.25 the specific energy deposition and the resulting temperature and pressure rise are compared for different materials. Lithium has the lowest mass number and therefore the temperature rise has the lowest value. Beryllium and graphite have a rather high Debye temperature and do not reach their full heat capacity at room temperature. T 114
dE/dV [kJ/cm 3 ] 3 2 1 DRAFT including fragmentation incl. frag. and inclination 0 0 1 2 3 4 5 6 z [cm] graphite Figure 2.4.107: FLUKA [43] simulation of the energy deposition of a 740 MeV/u 238 U beam with intensity 10 12 per spill in graphite (ρ = 1.84 g/cm 3 ) with a round Gaussian beam spot size with σ� = 1 cm. The ratio of dE/dV at the entrance compared to the peak is only 3.1 compared to 6.9 [45] without nuclear reactions. An inclined entrance with slope 0.1 further reduces this ratio to only 1.8. Table 2.4.25: Specific energy deposition at an energy of 740 MeV/u at the entrance of the beam catcher,, maximum energy deposition in the Bragg peak including the fragmentation process, initial temperature (Ti), the resulting maximum temperature (∆T) and pressure rise (∆P) for one spill of a fast extracted uranium beam at a maximum energy density dumped on a spot size of σx*σy = 1.7cm 2 corresponding to the minimum spot size resulting from Figure 2.4.106. The specific heat, thermal expansion coefficient and bulk modulus for the calculation were taken from refs. [46,76]. Intensity per spill Material dE/d(ρx) [MeV/mg cm 2 ] dE/d(ρx)eff [MeV/mg cm 2 ] in Bragg peak Ti [K] ∆T [K] ∆P [MPa] 6x10 11 Li 18.0 36 490 88 230 6x10 11 Be 17.6 36 293 163 720 6x10 11 C (graphite 1 ) 19.4 59 773 279 25 10 10 Al 17.5 70 300 11.4 60 10 10 H2O 22.1 46 300 1.7 6.6 The pressure rise of 720 MPa exceeds the yield strength of beryllium. Beryllium can therefore not be used. As a consequence this rules out a solution of liquid lithium with a beryllium entrance window. Lithium cannot be used in combination with carbon due to the chemical reactions. Only a windowless lithium beam catcher could in principle satisfy the requirements. Considering the low density of lithium of 0.54 g/cm 3 the catcher would be about 50 cm long, at least 20 cm wide resulting in a required flow of about 1 m 3 /s of liquid lithium that would have to be pumped. Such a realization would entail many technical problems and limits. 1 Values based on SGL carbon group grade R 6650. 115
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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
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DRAFT Figure 2.4.31: Cross section
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Figure 2.4.34: Sketch of the therma
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DRAFT To fulfill the required field
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DRAFT Figure 2.4.39: The 3D model o
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DRAFT Pole radius mm 100 210 250 25
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DRAFT Figure 2.4.43: Front, side, a
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∆B/B 0.0 DRAFT Figure 2.4.46: Ave
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DRAFT Figure 2.4.50: 3D model of th
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DRAFT Figure 2.4.54 and Table 2.4.1
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DRAFT 2.4.2.3.1 Radiation resistant
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DRAFT The water-cooled radiator con
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DRAFT Table 2.4.17: Coil parameters
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DRAFT Figure 2.4.63: Field distribu
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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 and 86: DRAFT Figure 2.4.82: Two hybrids ca
Page 87 and 88: DRAFT Figure 2.4.84: Left panel: TP
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: DRAFT Figure 2.4.106: Spot size of
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
Page 137 and 138: DRAFT These results show that the i
Page 139 and 140: DRAFT Like in the case of the rotat
Page 141 and 142: DRAFT Figure 2.4.126: Left: Schemat
Page 143 and 144: DRAFT Figure 2.4.128: Schematic lay
Page 145 and 146: DRAFT Figure 2.4.129: Flow scheme o
Page 147 and 148: DRAFT Since the weight of the cold
Page 149 and 150: DRAFT With the cooling capacity spe
Page 151 and 152: DRAFT Figure 2.4.134: Schematic of
Page 153 and 154: S1 (a) Figure 2.4.136: (a) Zoom of
Page 155 and 156: 2.4.A Appendix DRAFT The appendix o
Page 157 and 158: DRAFT experiment the EXL community
Page 159 and 160: 2.4.A1.3 Slow control and monitorin
Page 161 and 162: DRAFT Figure 2.4.139: Architecture
Page 163 and 164: 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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