Hartin, A. F.

Paper	Title	Page
MOPP027	Placet Based Start-to-end Simulations of the ILC with Intra-train Fast Feedback System	604
	J. Resta-López, P. Burrows, A. F. Hartin JAI, Oxford A. Latina, D. Schulte CERN, Geneva
	Integrated simulations are important to assess the reliability of the luminosity performance of the future linear colliders. In this paper we present multi-bunch tracking simulation results for the International Linear Collider (ILC) from the start of the LINAC to the interaction point. The tracking along the LINAC and the beam delivery system is done using the code Placet. This code allows us to introduce cavity wakefield effects, element misalignment errors and ground motion. Static beam based alignment of the LINAC are also considered. The luminosity and beam-beam parameters are calculated using the code Guinea-Pig. In the framework of the Feedback On Nano-second Timescales (FONT) project, we describe and simulate an updated fast intra-train feedback system in order to correct for luminosity degradation mainly due to high frequency ground motion.
MOPP008	Design of the Photon Collimators for the ILC Positron Helical Undulator	565
	A. Bungau UMAN, Manchester I. R. Bailey, J. B. Dainton, K. M. Hock, L. J. Jenner, L. I. Malysheva Liverpool University, Science Faculty, Liverpool E. Baynham, T. W. Bradshaw, F. S. Carr, J. Rochford STFC/RAL/ASTeC, Chilton, Didcot, Oxon A. J. Brummitt, A. J. Lintern STFC/RAL, Chilton, Didcot, Oxon J. A. Clarke, O. B. Malyshev, N. C. Ryder, D. J. Scott STFC/DL/ASTeC, Daresbury, Warrington, Cheshire N. A. Collomb STFC/DL, Daresbury, Warrington, Cheshire A. F. Hartin OXFORDphysics, Oxford, Oxon S. Hesselbach, G. A. Moortgat-Pick Durham University, Durham L. Zang Cockcroft Institute, Warrington, Cheshire
	A number of photon collimators are placed inside the helical undulator to protect the cold surfaces of the vacuum vessel from being hit by the photons and thus achieving the baseline pressure requirement. Computer simulations were run in order to determine the energy deposition and instantaneous temperature rise in these collimators and various material candidates were studied. This paper presents the status of the simulation.
MOPP070	Construction of a Full Scale Superconducting Undulator Module for the International Linear Collider Positron Source	709
	J. A. Clarke, O. B. Malyshev, D. J. Scott, B. J.A. Shepherd STFC/DL/ASTeC, Daresbury, Warrington, Cheshire I. R. Bailey, J. B. Dainton, K. M. Hock, L. J. Jenner, L. I. Malysheva, L. Zang Liverpool University, Science Faculty, Liverpool E. Baynham, T. W. Bradshaw, A. J. Brummitt, F. S. Carr, A. J. Lintern, J. Rochford STFC/RAL, Chilton, Didcot, Oxon A. Bungau UMAN, Manchester N. A. Collomb STFC/DL, Daresbury, Warrington, Cheshire A. F. Hartin OXFORDphysics, Oxford, Oxon S. Hesselbach, G. A. Moortgat-Pick Durham University, Durham Y. Ivanyushenkov ANL, Argonne, Illinois N. C. Ryder University of Bristol, Bristol
	The positron source for the ILC is dependent upon a >200m long undulator to generate a high flux of multi-MeV photons. The undulator system is broken down into a series of 4m cryomodules, which each contain two superconducting helical undulators. Following a dedicated R&D phase and the construction and measurement of a number of short prototypes a full scale cryomodule has now been completed for the first time. This paper reports on the design, manufacture, and test results of this cryomodule.
TUPC033	IP BPM Position Error at CLIC due to Secondary Emission from Beam-beam Backgrounds	1122
	A. F. Hartin, R. Apsimon, P. Burrows, C. I. Clarke, C. Perry, C. Swinson OXFORDphysics, Oxford, Oxon G. B. Christian ATOMKI, Debrecen B. Constance, H. Dabiri Khah JAI, Oxford A. Kalinin STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
	Beam-beam background impacts on the IP BPM are studied for the CLIC machine. The large number of coherent pairs ( 1.8×108 charges per BPM strip per bunch crossing) for the CLIC-G default parameter set, potentially leads to a large secondary emission in the BPM strips. Detailed GuineaPig++ and Geant studies reveal, however, that the coherent pairs travel down the extraction line without significant secondary showering. Geant studies of the CLIC incoherent pairs show a flux of secondary emission two orders of magnitude less than that expected for the ILC 1 TeV high luminosity scheme. Since previous studies showed that FONT IP BPM signal distortion for the ILC was of no concern, then it can also be neglected at CLIC.
MOPP024	Depolarization and Beam-beam Effects at the Linear Collider	598
	G. A. Moortgat-Pick, S. Hesselbach Durham University, Durham I. R. Bailey, G. A. Moortgat-Pick, B. J.A. Shepherd Cockcroft Institute, Warrington, Cheshire D. P. Barber DESY, Hamburg E. Baynham, T. W. Bradshaw, F. S. Carr, J. Rochford STFC/RAL/ASTeC, Chilton, Didcot, Oxon A. J. Brummitt, A. J. Lintern STFC/RAL, Chilton, Didcot, Oxon A. Bungau UMAN, Manchester J. A. Clarke, O. B. Malyshev, N. C. Ryder, D. J. Scott STFC/DL/ASTeC, Daresbury, Warrington, Cheshire J. B. Dainton, K. M. Hock, L. J. Jenner, L. I. Malysheva, L. Zang Liverpool University, Science Faculty, Liverpool A. F. Hartin OXFORDphysics, Oxford, Oxon
	The clean environment at the interaction point of a lepton linear collider allows high-precision measurements for physics analyses. In order to exploit this potential, precise knowledge about the polarization state of the beams is also required. In this paper we concentrate on depolarization effects caused by the intense beam-beam interaction, which is expected to be the dominant source of depolarization. Higher-order effects, as well as critical analyses of the theoretical assumptions used in the past and theoretical improvements in the derivation of suitable equations, are given. Updates on existing simulation programs are reported. Numerical results for the design of the International Linear Collider (ILC) are discussed.
WEOBG03	The Design of the Positron Source for the International Linear Collider	1915
	J. A. Clarke, O. B. Malyshev, D. J. Scott STFC/DL/ASTeC, Daresbury, Warrington, Cheshire I. R. Bailey, J. B. Dainton, K. M. Hock, L. J. Jenner, L. I. Malysheva, L. Zang Liverpool University, Science Faculty, Liverpool E. Baynham, T. W. Bradshaw, A. J. Brummitt, F. S. Carr, A. J. Lintern, J. Rochford STFC/RAL, Chilton, Didcot, Oxon V. Bharadwaj, J. Sheppard SLAC, Menlo Park, California A. Bungau UMAN, Manchester N. A. Collomb STFC/DL, Daresbury, Warrington, Cheshire R. Dollan Humboldt Universität zu Berlin, Berlin W. Gai, Y. Ivanyushenkov, W. Liu ANL, Argonne, Illinois J. Gronberg, W. T. Piggott LLNL, Livermore, California A. F. Hartin OXFORDphysics, Oxford, Oxon S. Hesselbach, G. A. Moortgat-Pick Durham University, Durham K. Laihem, S. Riemann, A. Schaelicke, A. Ushakov DESY Zeuthen, Zeuthen T. Lohse Humboldt University Berlin, Institut für Physik, Berlin A. A. Mikhailichenko Cornell University, Department of Physics, Ithaca, New York N. C. Ryder University of Bristol, Bristol
	The high luminosity requirements and the option of a polarized positron beam present a great challenge for the positron source of a future linear collider. This paper provides a comprehensive overview of the latest proposed design for the baseline positron source of the International Linear Collider. We report on recent progress and results concerning the main components of the source: including the undulator, collimators, capture optics, and target.
	Slides
THPC114	Design and Performance of a Prototype Digital Feedback System for the International Linear Collider Interaction Point	3245
	P. Burrows, B. Constance, H. Dabiri Khah, J. Resta-López JAI, Oxford R. Apsimon, P. Burrows, C. I. Clarke, A. F. Hartin, C. Perry, C. Swinson OXFORDphysics, Oxford, Oxon G. B. Christian ATOMKI, Debrecen A. Kalinin STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
	We present the design and preliminary results of a prototype beam-based digital feedback system for the Interaction Point of the International Linear Collider. A custom analogue front-end processor, FPGA-based digital signal processing board, and kicker drive amplifier have been designed, built, and tested on the extraction line of the KEK Accelerator Test Facility (ATF). The system was measured to have a base latency of approximately 140 ns, increasing to approximately 148 ns with the inclusion of real-time charge normalisation.