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Using the TEVATRON beam position monitor system to investigate transverse phase space

Description: Transverse phase space trajectories can be measured by using the TEVATRON beam position monitor in the standard turn by turn operation mode if a coherent betratron oscillation is excited by a dipole kick. The measurement of phase space coordinates is influenced by incoherent and coherent synchrotron oscillations and incoherent betatron oscillations. In order to investigate phase space trajectories in detail, all these effects must be understood quantitatively and if possible the measured data must be corrected. In this report the measuring and correction procedures will be investigated and the first measurements will be discussed.
Date: May 1, 1985
Creator: Willeke, F.
Partner: UNT Libraries Government Documents Department

Study of the tevatron nonlinear acceptance by computer simulation

Description: In this report, the results of computer calculations of nonlinear acceptance reduction caused by nonlinear fields in the TEVATRON are presented. A set of test particles has been traced during many revolutions in the accelerator in order to determine the maximum stable amplitude in the presence of nonlinear fields. Sources of nonlinear fields are designed imperfections of dipole and quadrupole magnets, fluctuations due to manufacturing tolerances, and sextupole fields needed to compensate for chromaticity.
Date: November 1, 1983
Creator: Willeke, F.
Partner: UNT Libraries Government Documents Department

Aperture studies with Patricia and Racetrack on simple lattices containing SSC dipoles

Description: The PATRICIA and RACETRACK particle tracking programs have been compared by tracking on a simple lattice. The dynamic aperture was found to decrease as the number of passes through the lattice per run increased from 20 to approx. 300, and it remained constant for longer runs. The dynamic apertures found by the two programs are consistent. The dependence of the dynamic aperture on horizontal tune near a decapole resonance was investigated. RACETRACK and PATRICIA showed decreases in the aperture on opposite sides of the resonance. A second set of studies was made with PATRICIA in which the dynamic apertures of lattices consisting of cells of the types used for the Reference Designs Study were determined when random multipole errors of the dipoles were included. The dependence of aperture on the number of cells in the lattice was determined. Finally, a comparison of magnet types suggested for the SSC was made by determining the aperture of lattices containing these magnets.
Date: June 23, 1984
Creator: Dell, G.F.; Leemann, B. & Willeke, F.
Partner: UNT Libraries Government Documents Department

Control and initial operation of the Fermilab BO low. beta. insertion

Description: The operation of the Fermilab BO low ..beta.. insertion involves the coordinated control of the 4 strings of quadrupoles of the insertion itself along with several magnetic correction elements (20 dipoles for the closed orbit, 2 quad circuits for betatron tunes, 1 skew quad circuit for coupling, and 2 sextupole circuits for chromaticity). When the beam is stored at high energy, these elements must correct the errors induced by the strong superconducting quadrupoles of the insertion as the optics are smoothly changed from the fixed target configuration to the low ..beta.. state. The techniques and control programs for these manipulations and initial tests using a single coasting beam are described. 6 refs., 4 figs.
Date: June 1, 1985
Creator: Finley, D.A.; Johnson, R.P. & Willeke, F.
Partner: UNT Libraries Government Documents Department

IMPLEMENTATION OF A DC BUMP AT THE STORAGE RING INJECTION STRAIGHT SECTION

Description: The NSLS II beam injection works with a DC septum, a pulsed septum and four fast kicker magnets. The kicker power supplies each produce a two revolution period pulsed field, 5.2 {micro}s half sine waveform, using {approx}5kA drive voltage. The corresponding close orbit bump amplitude is {approx}15mm. It is desired that the bump is transparent to the users for top-off injection. However, high voltage and short pulse power supplies have challenges to maintain pulse-to-pulse stability and magnet-to-magnet reproducibility. To minimize these issues, we propose implementing a DC local bump on top of the fast bump to reduce the fast kicker strength by a factor of 2/3. This bump uses two storage ring corrector magnets plus one additional magnet at the septum to create a local bump. Additionally, these magnets could provide a DC bump to simulate the septum position effects on the store beam lifetime. This paper presents the detail design of this DC injection bump and related beam dynamics.
Date: March 28, 2011
Creator: Wang, G.M.; Shaftan, T.; Kramer, S.K.; Fliller, R.; Guo, W.; Heese, R. et al.
Partner: UNT Libraries Government Documents Department

Short pulse generation by laser slicing at NSLSII

Description: We discuss an upgrade R&D project for NSLSII to generate sub-pico-second short x-ray pulses using laser slicing. We discuss its basic parameters and present a specific example for a viable design and its performance. Since the installation of the laser slicing system into the storage ring will break the symmetry of the lattice, we demonstrate it is possible to recover the dynamical aperture to the original design goal of the ring. There is a rapid growth of ultrafast user community interested in science using sub-pico-second x-ray pulses. In BNL's Short Pulse Workshop, the discussion from users shows clearly the need for a sub-pico-second pulse source using laser slicing method. In the proposal submitted following this workshop, NSLS team proposed both hard x-ray and soft x-ray beamlines using laser slicing pulses. Hence there is clearly a need to consider the R&D efforts of laser slicing short pulse generation at NSLSII to meet these goals.
Date: March 28, 2011
Creator: Yu, L.; Blednykh, A.; Guo, W.; Krinsky, S.; Li, Y.; Shaftan, T. et al.
Partner: UNT Libraries Government Documents Department

Alternative Designs for the NSLS-II Injection Straight Section

Description: Brookhaven National Laboratory (BNL) is developing a state-of-the-art 3 GeV synchrotron light source, the NSLS-II [1]. The 9.3 meter-long injection straight section of its storage ring now fits a conventional injection set-up consisting of four kickers producing a closed bump, together with a DC septum and a pulsed septum. In this paper, we analyze an alternative option based on injection via a pulsed sextupole magnet. We discuss the dynamics of the injected and stored beams and, subsequently, the magnet's specifications and tolerances. We conclude by summarized the advantages and drawbacks of each injection scheme.
Date: May 4, 2009
Creator: Shaftan,T.; Heese, R.; Weihreter, E.; Willeke, F.; Rehak, M.; Meier, R. et al.
Partner: UNT Libraries Government Documents Department

NSLS-II Beam Diagnostics Overview

Description: A new 3rd generation light source (NSLS-II) is in the early stages of construction at Brookhaven National Laboratory. The NSLS-II facility will provide ultra high brightness and flux with exceptional beam stability. It presents several challenges for diagnostics and instrumentation, related to the extremely small emittance. In this paper, we present an overview of all planned instrumentation systems, results from research and development activities; and then focus on other challenging aspects.
Date: May 4, 2009
Creator: Singh,O.; Alforque, R.; Bacha, B.; Blednykh, A.; Cameron, P.; Cheng, W. et al.
Partner: UNT Libraries Government Documents Department