Technical Design Report Super Fragment Separator

More documents

Recommendations

Info

DRAFT ments with exotic nuclei: the energy-buncher stage will provide slow (Ekin ~ 100...1 MeV/u) monoenergetic (δE ~ 1 MeV/u) beams and will allow stopping exotic nuclei in very thin implantation arrays (~ mg/cm2) or in helium-filled (gaseous or superfluid) stopping cells. From the latter, singly-charged ions of all elements can be extracted and post-accelerated to a few 10 keV for physics experiments (see section 2.4.11.2.4). Adapted to the ion-optical parameters of the energy buncher, the calculated envelopes of the ion beams, and the properties during the slowing down, the following dimensions and tolerances have been calculated for the degrader system at focal plane MF11: Width (cm) Height (cm) Thickness (g/cm 2 ) Wedge angle (mrad) Tolerances (µm) 60 20 0.5-20 0-120 140 Similar to the other focal planes, this unit will comprise wedges, disks, and homogeneous plates to yield the necessary flexibility. The large dimensions need special care. A prototype is under development to gain experience and to test under realistic conditions at the FRS the performance and possible radiation damage or modifications of the material. Figure 2.4.117 shows the drawings and the first mechanical linear drives during assembly. Figure 2.4.117: Drawings and first parts while mounting the prototype of the degrader for the energy buncher. This prototype will be used and tested for the FRS Ion Catcher setup. 2.4.11.2.4 Ion catcher This stopping unit and its related components (beam extraction, cooling, bunching, and distribution system) as well as results from their performance characterization are described in the Low-Energy-Branch Technical Report [60]. For the Super-FRS Ion Catcher there is an R&D program underway. Figure 2.4.118 shows the prototype of an ion-catcher and beam-distribution system, which has been setup and optimized off-line in collaboration with ANL Argonne, MSU, and Giessen University. The system has been 128
DRAFT commissioned in February 2005 and characterized with relativistic 58 Ni ions at the FRS [61], see Figure 2.4.119. During the on-line test, an overall efficiency of (1.8 ± 0.3) % has been achieved at a gas cell pressure of 100 mbar helium, which can be divided into a stopping efficiency of (5.0 ± 1.1) % and an extraction and transport efficiency of (35 ± 9) %. The overall efficiency is hence limited mostly by the stopping efficiency, which could be increased in the future by operating the stopping cell at higher pressures. From extraction time measurements of polyatomic ions formed in the gas cell extraction times of atomic ions of 20 ms to 50 ms can be derived. In these tests, only beam intensities of 2 ⋅ 10 5 ions per spill every ~ 8 s were used. However, on-line tests with a similar gas cell, operated at the MLL tandem accelerator at Munich, have shown the promising result that the overall efficiency of the stopping/extraction system stays constant up to intensities of a few 10 8 107 Ag-ions per second [62]. To circumvent problems with molecular contamination created in the gas cell in the future, a cryogenic stopping cell cooled with liquid nitrogen is under development in collaboration with KVI Groningen. This stopping cell will also allow reduced diffusion losses to the walls of the device. As an alternative approach, groups of JYFL Jyväskylä and KVI Groningen are developing and investigating the possibility to stop and extract exotic nuclei in/from superfluid liquid helium[63]. Similar extraction times and efficiencies as in the case of gaseous helium are expected, but the approximately 800 times higher density (as compared to gaseous helium at standard temperature and pressure) will allow for a much more compact apparatus. After thermalization in superfluid helium, positive ions form “snowballs” – clusters of helium atoms that form around positive ions due to electrostriction. Applying electrical drag fields, the snowballs drift to the superfluid helium surface and escape to the vapour region with high efficiency. In the near future further tests with improved setups are planned: off-line tests at KVI and on-line tests at JYFL. These studies will be further pursued as part of the European DIRAC design study. Figure 2.4.118: Off-line setup of a high-pressure helium-filled stopping system for relativistic heavy ions. 129
Page 1 and 2:
DRAFT Technical Design Report Super
Page 3 and 4:
Preface DRAFT The International Fac
Page 5 and 6:
Contents DRAFT 2.4.1 System Design
Page 7 and 8:
DRAFT Table 2.4.1: Parameters of th
Page 9 and 10:
DRAFT degrader stage which provides
Page 11 and 12:
Pre-Separator DRAFT In order to acc
Page 13 and 14:
DRAFT coupling coefficients is give
Page 15 and 16:
DRAFT Table 2.4.3: First-order matr
Page 17 and 18:
DRAFT Main-Separator to the high-en
Page 19 and 20:
DRAFT Table 2.4.5: Transmission T o
Page 21 and 22:
DRAFT Figure 2.4.15: Resolution nec
Page 23 and 24:
DRAFT Figure 2.4.17: Spectrometer m
Page 25 and 26:
DRAFT Table 2.4.8: Design parameter
Page 27 and 28:
DRAFT Figure 2.4.20: Side view of t
Page 29 and 30:
DRAFT Figure 2.4.23: Coil cross-sec
Page 31 and 32:
DRAFT Figure 2.4.25: Flux density d
Page 33 and 34:
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 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 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: DRAFT material) and received the an
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
Page 165 and 166: DRAFT source tier are split in two
Page 167 and 168: DRAFT coupled from the ACS which is
Page 169 and 170: DRAFT 2.4.A3.2 Work packages: descr
Page 171 and 172: 2.4.A3.2.4 Instrumentation Measurin
Page 173 and 174: DRAFT this, planning a network layo
Page 175 and 176: DRAFT 2.4.A3.3 Machine characterist
Page 177 and 178: DRAFT installation of RALF was done
Page 179 and 180:
DRAFT The double ring synchrotrons,
Page 181 and 182:
DRAFT The first refrigerator, Cryo1
Page 183 and 184:
DRAFT shield 28874 + 25 g/s 22 bar
Page 185 and 186:
LHe storage Helium storage Helium s
Page 187 and 188:
Cryo2 Cryo3 CryoST DB 3 DRAFT Compr
Page 189 and 190:
DRAFT The cold connection will be m
Page 191 and 192:
DRAFT Measurements planned for each
Page 193 and 194:
DRAFT For magnets with less stringe
Page 195 and 196:
DRAFT The value, parameters, condit
Page 197 and 198:
DRAFT 3. Geometry tests For cryosta
Page 199 and 200:
DRAFT The Quench Heaters Tests has
Page 201 and 202:
DRAFT Figure 2.4.159: Photograph of
Page 203 and 204:
DRAFT The field properties listed i
Page 205 and 206:
DRAFT Figure 2.4.161: Schematic vie
Page 207 and 208:
DRAFT Figure 2.4.162: Scheme of the
Page 209 and 210:
2.4.A6.2.2 Shielding against direct
Page 211 and 212:
DRAFT Figure 2.4.164: Schematic lay
Page 213 and 214:
DRAFT Figure 2.4.165: An iron beam
Page 215 and 216:
DRAFT In a side view the flux of pr
Page 217 and 218:
DRAFT catcher 7 Be, 22 Na and 24 Na
Page 219 and 220:
DRAFT at the FRS (2·10 9 /spill as
Page 221 and 222:
DRAFT [1] H. Geissel et al., Nucl.
Page 223 and 224:
DRAFT [74] A. Fabich and J. Lettry,
show all

Technical Design Report Super Fragment Separator

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?