1 FOREWORD ..................................................... 9
1.1 Prom the Chair .......................................... 9
1.2 From the Editor ........................................ 11
1.3 From the ILC GDE ....................................... 11
2 POSITRON SOURCE FOR ILC ..................................... 12
2.1 Positron Source for the International Linear
Collider ............................................... 12
2.1.1 Introduction .................................... 12
2.1.1.1 Layout as in RDR Baseline .............. 13
2.1.1.2 Layout as in SB2009 Proposal ........... 14
2.1.1.3 Critical Components of Undulator
Based Positron Source .................. 15
2.1.2 The RDR Undulator Based Positron Source ......... 20
2.1.3 The SB2009 Undulator Based Positron Source ...... 23
2.1.4 High К Short Period Undulator ................... 25
2.1.5 References ...................................... 26
3 ILC DAMPING RINGS ........................................... 27
3.1 Damping Rings Overview ................................. 27
3.1.1 Introduction .................................... 27
3.1.2 ILC Damping Ring Design Status .................. 28
3.1.3 ILC Damping Ring R&D Status ..................... 29
3.1.4 References ...................................... 31
3.2 An Update on the CESR Test Accelerator Research
Program ................................................ 32
3.2.1 Introduction .................................... 32
3.2.2 Conversion of CESR to a Damping Ring Test
Accelerator Configuration ....................... 33
3.2.3 Electron Cloud Build-Up and Mitigation
Studies ......................................... 36
3.2.3.1 EC Mitigation in Dipole Magnets ........ 37
3.2.3.2 EC Mitigation in Wiggler Magnets ....... 38
3.2.3.3 EC Mitigation in Drift Regions ......... 39
3.2.3.4 EC mitigation in Quadrupole Magnets .... 40
3.2.3.5 ТЕ Wave Measurements ................... 41
3.2.3.6 Shielded Pickup Measurements ........... 41
3.2.4 Low Emittance Tuning ............................ 42
3.2.5 Studies of EC-induced Beam Dynamics with Low
Emittance Beams ................................. 43
3.2.6 Incorporation of CESRTA Results into the ILC
DR Technical Design ............................. 44
3.2.7 Future Plans .................................... 45
3.2.8 Acknowledgments ................................. 45
3.2.9 References ...................................... 45
3.3 Recent Studies in ATF Damping ring ..................... 47
3.3.1 Introduction .................................... 47
3.3.2 Low Emittance Tuning in ATF Damping Ring ........ 48
3.3.2.1 Beam Based Alignment ................... 48
3.3.2.2 Beta-Beat Correction ................... 49
3.3.2.3 Orbit Response Matrix Analysis ......... 50
3.3.2.4 BPM Electronics Upgrade ................ 50
3.3.3 Fast Kicker Test ................................ 51
3.3.3.1 Beam Extraction Experiment ............. 51
3.3.4 References ...................................... 55
3.4 ILC 3.2 км Damping Ring Design Based on the FODO
Cell ................................................... 56
3.4.1 Introduction .................................... 56
3.4.2 Global Consideration and Parameter
Calculation ..................................... 57
3.4.3 Linear Lattice Design ........................... 59
3.4.4 Dynamic Aperture ................................ 60
3.4.5 References ...................................... 62
4 FINAL FOCUS TEST FACILITY FOR ILC AND CLIC .................. 62
4.1 ATF2 Summary and Status ................................ 62
4.1.1 Introduction .................................... 63
4.1.2 Sub-Systems Hardware ............................ 66
4.1.2.1 Magnets and Magnet Movers .............. 66
4.1.2.2 Beam Position Monitors (BPMs) .......... 67
4.1.2.3 IP Beam Size Monitors .................. 68
4.1.2.4 EXT Beam Phase-Space Diagnostics
(Wire-Scanners and OTRs) ............... 68
4.1.2.5 Beam Loss Monitor ...................... 68
4.1.2.6 Intra-Pulse Feedback ................... 69
4.1.2.7 Background Radiation Monitors .......... 69
4.1.3 Accelerator Modeling Software ................... 69
4.1.3.1 Optics Design and Beam Dynamics
Simulations ............................ 69
4.1.3.2 Online Model and Control System
Interface .............................. 69
4.1.4 Optics Preparation and Beam Dynamics
Simulations ..................................... 70
4.1.5 Beam Tuning Procedure ........................... 72
4.1.5.1 Beam-Based Alignment (ВВЛ) ............. 72
4.1.5.2 Orbit Response and Jitter Modelling .... 73
4.1.5.3 Orbit Steering & Feedbacks ............. 74
4.1.5.4 Dispersion Measurement and
Correction ............................. 75
4.1.5.5 Twiss Parameters & Coupling
Measurement and Correction ............. 76
4.1.5.6 IP Vertical Beam Size Tuning ........... 77
4.1.6 Summary and Outlook ............................. 78
4.1.7 References ...................................... 78
4.2 Measurement of Nanometer Scale Beam Size by Shintake
Monitor (IPBSM) ........................................ 80
4.2.1 Introduction .................................... 81
4.2.1.1 Shintake Monitor's Role at ATF2 ........ 81
4.2.2 Measurement Scheme of Shintake Monitor .......... 82
4.2.3 Layout and Structure ............................ 85
4.2.3.1 Overall Structure ...................... 85
4.2.3.2 Laser Table and Main Optical Table ..... 85
4.2.3.3 Gamma Detector ......................... 87
4.2.4 Shintake Monitor and Beam Tuning ................ 87
4.2.5 Performance ..................................... 88
4.2.5.1 Expectations ........................... 88
4.2.5.2 Statistical Errors ..................... 88
4.2.5.3 Systematic Errors ...................... 90
4.2.6 Status .......................................... 92
4.2.6.1 Previous Run ........................... 92
4.2.6.2 Most Recent Run (2010 Autumn - 2011
Spring) ................................ 92
4.2.7 Future Coals .................................... 93
4.2.7.1 Remaining of Current Run Period ........ 93
4.2.7.2 Consequences of the Great Eastern
Japan Earthquake ....................... 94
4.2.7.3 Prospects for Application at ILC ....... 94
4.2.8 Footnotes ....................................... 95
4.2.9 References ...................................... 95
4.3 The Multi Optical Transition Radiation System .......... 96
4.3.1 Introduction .................................... 96
4.3.2 The Beam Diagnostic Section of the ATF2
Extraction Line: Optics Studies and Beam Spot
Size Simulations ................................ 96
4.3.3 Technical Description: Optical and Mechanical
Design .......................................... 98
4.3.4 Software Integration, Beam Spot Size and
Emittance Reconstruction Algorithms ............ 101
4.3.4.1 Beam Spot Size and Emittance
Reconstruction Algorithms ............. 103
4.3.5 First Beam Measurements ........................ 103
4.3.5.1 Fall Run 2010 ......................... 103
4.3.5.2 First Period Run 2011 ................. 105
4.3.6 Conclusions .................................... 105
4.3.7 Acknowledgements ............................... 106
4.3.8 References ..................................... 106
4.4 Micron Scale Laser-Wire Scanner for the ATF ........... 106
4.4.1 Introduction ................................... 107
4.4.2 Laser-Wire Experiment at the ATF ............... 107
4.4.2.1 Hardware .............................. 107
4.4.2.2 Lens Simulation ....................... 108
4.4.2.3 Laser-Wire Results .................... 109
4.4.3 Laser-Wire Upgrade for the AIF2 ................ 110
4.4.3.1 Upgrades .............................. 110
4.4.3.2 Laser-Wire Results at the ATF2 ........ 110
4.4.4 Development of a New Fibre Laser Source for
Laser-Wire Experiments ......................... 111
4.4.5 Development of an Electro-Optic Scanner lor
Fast Laser-Wire Operation ...................... 112
4.4.6 Conclusions and Future Plans ................... 115
4.4.7 References ..................................... 115
5 ACTIVITY REPORTS ........................................... 116
5.1 Recent Luminosity Enhancement at the BEPCil ........... 116
5.1.1 Introduction ................................... 116
5.1.2 Luminosity Commissioning in 2010- 2011 ......... 117
5.1.3 Future Improvements ............................ 119
5.1.4 References ..................................... 119
5.2 Accelerator Design of China Spallation Neutron
Source ................................................ 120
5.2.1 Introduction ................................... 120
5.2.2 Beam Dynamics Design ........................... 121
5.2.2.1 Linac ................................. 121
5.2.2.2 Rapid Cycling Synchrotron ............. 122
5.2.2.3 Beam Lines ............................ 122
5.2.3 Acknowledgements ............................... 122
5.2.4 References ..................................... 123
5.3 The Accelerator. Lab at Tsinghua University ........... 123
5.3.1 Introduction ................................... 123
5.3.2 Low Energy Linac ............................... 123
5.3.3 Tsinghua Thomson Scattering X-ray (TTX)
Source ......................................... 124
5.3.4 MeV Ultrafast Electron Diffraction Based on
Photocathode RF Gun ............................ 125
5.4 SRF Technology at Peking University ................... 127
5.4.1 Introduction ................................... 127
5.4.2 RF Superconducting Cavities .................... 127
5.4.2.1 3.5-Cell Cavity ....................... 127
5.4.2.2 9-Cell Cavity ......................... 127
5.4.2.3 QWR and Spoke Cavity .................. 128
5.4.3 PKU-SETF ....................................... 128
5.5 New Low Charge Parameters for LLC ..................... 129
5.5.1 Introduction ................................... 129
5.5.2 Main Changes in the New Low Charge Parameters
Compared to SB2009 ............................. 131
5.5.3 Advantages of the New Low Charge Parameter ..... 132
5.5.4 New Design for the Two-Stage Bunch
Compressor ..................................... 132
5.5.5 References ..................................... 133
5.6 First Beam Manipulation and Measurements in the
Final Focus Beam Line at the KEK Accelerator Test
Facility .............................................. 133
5.6.1 Introduction ................................... 133
5.6.2 Simulation on Multiknobs Correction ............ 134
5.6.2.1 Multiknobs Correction Analysis ........ 134
5.6.2.2 Simulation Results on Multiknobs
Correction ............................ 134
5.6.2.3 Summary and Prospects ................. 136
5.6.3 Twiss Parameter Estimation ..................... 136
5.6.3.1 Parametrisation of Beam Sizes Around
the IP and Post-IP Waists ............. 136
5.6.3.2 Estimation of Twiss Parameters and
of Horizontal Emittance ............... 137
5.6.3.3 Discussion ............................ 140
5.6.4 References ..................................... 140
5.7 Linac Beam Mismatch Modes for Unequal Transverse
Tunes ................................................. 141
5.7.1 Introduction ................................... 141
5.7.2 Case of Equal Transverse Tunes ................. 142
5.7.3 Instability for Equal Transverse Tunes ......... 143
5.7.4 Case of Unequal Transverse Tunes ............... 143
5.7.5 Case of Unequal Transverse Tunes and Envelope
Equation Non-Linearity ......................... l44
5.7.6 Inter-Stage Mismatch ........................... 145
5.7.7 Mismatch Mode Features ......................... 145
5.7.8 Envelope Modes for an Un-Bunched Beam with
Unequal Tunes .................................. 146
5.7.9 Appendix: Homogeneous Linear Equations for
the Mismatch Modes ............................. 146
5.7.10 References ..................................... 147
5.8 Reduced Emittance Growth in a Long MEBT Stage of a
Linac ................................................. 148
5.8.1 Introduction ................................... 148
5.8.2 A3 MeV, Long MEBT Option for an ISIS Upgrade ... 149
5.8.3 The Basis of the Need for a Second Harmonic
Cavity ......................................... 150
5.8.4 Beam Tracking Results for the Modified MEBT .... 151
5.8.5 References ..................................... 152
6 WORKSHOP AND CONFERENCE REPORTS ............................ 152
6.1 X-Band Structures, Beam Dynamics and Sources
Workshop (XB-10) ...................................... 152
7 RECENT DOCTORIAL THESES .................................... 155
7.1 ILC Physical Design and Key Experimental Study ........ 155
7.2 A Damped and Detuned Accelerating Structure, for the
Main Linacs or the Compact Linear Collider ............ 156
8 FORTHCOMING BEAM DYNAMICS EVENTS ........................... 156
8.1 Sixth Workshop on Polarized Positron Beams (POSIPOL
2011) ................................................. 156
8.2 Sixth International Accelerator School for Linear
Colliders ............................................. 157
8.3 Workshop on Accelerators for Heavy Ion Inertial
Fusion (HIF2011) ...................................... 162
8.4 Second International Conference on Technology and
Instrumentation in Particle Physics (TIPP 2011) ....... 164
8.5 15TH International Conference on RF
Superconductivity (SRF2011) ........................... 165
8.6 13TH International Conference on Accelerator and
Large Experimental Physics Control Systems (ICALEPCS
2011) ................................................. 165
9 ANNOUNCEMENTS OF THE BEAM DYNAMICS PANEL ................... 166
9.1 ICFA Beam Dynamics Newsletter ......................... 166
9.1.1 Aim of the Newsletter .......................... 166
9.1.2 How to Prepare a Manuscript .................... 167
9.1.3 Distribution ................................... 167
9.1.4 Regular Correspondents ......................... 168
9.2 ICFA Beam Dynamics Panel Members ...................... 169
|
