Paper | Title | Other Keywords | Page |
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MOI1A02 | J-PARC Recovery Status | linac, extraction, status, vacuum | 6 |
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J-PARC facilities were seriously damaged by the Great East Japan Earthquake in March 2011, but all facilities resumed a beam operation from December 2012. We report the operation status of J-PARC accelerators after the earthquake. | |||
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Slides MOI1A02 [12.726 MB] | ||
MOP203 | Bunch-by-Bunch Beam Loss Diagnostics with Diamond Detectors at the LHC | beam-losses, injection, proton, simulation | 41 |
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A main challenge in the operation with high intensity beams is managing beam losses that imply the risk of quenching superconducting magnets or even damage equipment. There are various sources of beam losses, such as losses related to injection, to beam instabilities and to UFOs (Unidentified Falling Objects). Mostly surprising in the first years of LHC operation was the observation of UFOs. They are believed to be dust particles with a typical size of 1-100 um, which lead to beam losses with a duration of about ten revolutions when they fall into the beam. 3600 BLMs (Beam Loss Monitors) are installed around the LHC ring, allowing to determinate the accurate location of UFOs. The time resolution of the BLMs is 40 us (half a turn revolution). A measurement of the beam losses with a time resolution better than the bunch spacing of 50 ns is crucial to understand loss mechanisms. Diamond sensors are able to provide such diagnostics and perform particle counting with ns time resolution. In this paper, we present measurements of various types of beam losses with diamond detectors. We also compare measurements of UFO induced beam losses around the LHC ring with results from MadX simulations. | |||
MOP206 | Numerical Calculation of Beam Coupling Impedances for the SIS-100 Synchrotron for FAIR | impedance, coupling, space-charge, synchrotron | 54 |
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The transverse impedance of kicker magnets is considered to be one of the main beam instability sources in the projected SIS-100 at FAIR and also in the SPS at CERN. The longitudinal impedance can contribute to the heat load, which is especially a concern in the cold sections of SIS-100 and LHC. In the high frequency range, time domain codes are commercially available to calculate the impedance but they become inapplicable at medium and low frequencies. We present the ongoing work of developing a Finite Integration (FIT) solver in frequency domain which is based on the Parallel and Extensible Toolkit for Scientific computing (PETSc) framework in C++. The code is applied to an inductive insert used to compensate the longitudinal space charge impedance in low energy machines. Another application focuses on the impedance contribution of a ferrite kicker with inductively coupled pulse forming network (PFN) and frequency dependent complex material permeability. In future we plan to confirm our simulations with dedicated wire or coil bench measurements. | |||
MOP215 | The Study on Measuring Beta Functions and Phase Advances in the CSNS/RCS | space-charge, betatron, synchrotron, lattice | 85 |
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As a key component of the China Spallation Neutron Source (CSNS) Project, the Rapid Cycling Synchrotron (RCS) will accumulate and accelerate the proton beams from 80 MeV to 1.6 GeV for extracting and striking the target with a repletion rate of 25 Hz. To check linear optics and locate the quadruple errors, beta function plays an important role in beam diagnostics of a particle accelerate system. The Independent Component Analysis (ICA) is a robust beam diagnosis method by decomposing the samples recorded by turn by turn BPMs (beam position monitors) into the independent components which represent the inherent motion of the beam. The beta functions and phase advances can be derived from the corresponding independent components. Because the linear part of the space charge gives a defocusing effect to the beam, beta function variation will be induced. We find that the ICA method can measure beta functions with a reasonable tolerance under the conditions of strong space charge effects. | |||
MOP261 | A Test Facility for MEIC ERL Circulator Ring Based Electron Cooler Design | electron, SRF, FEL, cathode | 219 |
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Funding: * Supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC05-06OR23177 and DE-AC02-06CH11357. An electron cooling facility which is capable to deliver a beam with energy up to 55 MeV and average current up to 1.5 A at a high bunch repetition rate up to 750 MHz is required for MEIC. The present cooler design concept is based on a magnetized photo-cathode SRF gun, an SRF ERL and a compact circulator ring. In this paper, we present a proposal of a test facility utilizing the JLab FEL ERL for a technology demonstration of this cooler design concept. Beam studies will be performed and supporting technologies will also be developed in this test facility |
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WEO3A04 | Current and Planned High Proton Flux Operations at the FNAL Booster | booster, proton, extraction, radiation | 378 |
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Funding: Department of Energy - Office of High Energy Physics The Fermi Lab Proton Source has seen a dramatic increase in requested flux this past decade. An increase of over ten fold in hourly flux was necessary to meet the FNAL HEP experimental requirements. This next decade will be just as challenging as the lab's HEP planning will again require the Proton Source to double the hourly flux. The recent achievements were accomplished with major upgrades such a collimation system, new correctors and aperture improvements. To achieve the next level of proton delivery rates will require even more improvements. A five year Proton Improvement Plan (PIP) is currently underway with a goal to maintain 2012 activation levels while doubling the hourly flux. Tasks in the PIP to help reduce losses include an improved beam notching system, cogging, aperture improvement and beam emittances control and reduction. This talk will describe current conditions and plans to mitigate losses with the planned increase in proton throughput. |
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Slides WEO3A04 [8.309 MB] | ||
WEO3B03 | PXIE at FNAL | rfq, cavity, diagnostics, ion | 414 |
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PXIE is the integrated systems test for the Project X frontend. It is expected to accelerate 1-2 mA CW beam up to 30 MeV. The major goal of the project is a validation of the Project X concept and elimination of technical risks. It is expected to be constructed in the period of 2012-2016. In presentation the conceptual design of the experimental test facility, lattice and beam dynamics studies will be discussed in details. | |||
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Slides WEO3B03 [4.561 MB] | ||
THO1B02 | Test of Optical Stochastic Cooling in Fermilab | damping, radiation, optics, pick-up | 514 |
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A new 150 MeV electron storage ring is planned to be build in Fermilab. The construction of new machine pursues two goals a test of highly non-linear integrable optics and a test of optical stochastic cooling (OSC). This paper discusses details of OSC arrangements and choice of major parameters of the cooling scheme. At the first step the cooling will be achieved without optical amplifier. It should introduce the damping rates of about 1 order of magnitudes higher than the cooling rates due to synchrotron radiation. Similar scheme looks as a promising technique for the LHC luminosity upgrade. Its details are also discussed. | |||
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Slides THO1B02 [1.109 MB] | ||
THO1B05 | Broad-band Transverse Feedback against e-cloud or TMCI: Plan and Status | feedback, controls, electron, pick-up | 527 |
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The feedback control of intra-bunch instabilities driven by electron-clouds or strong head-tail coupling (Transverse mode coupled instabilities, TMCI) requires bandwidth sufficient to sense the vertical position and apply multiple corrections within a nanosecond-scale bunch. These requirements impose challenges and limits in the design and implementation of the feedback system. To develop the feedback control prototype, different research areas have been pursed to model and identify the bunch dynamics, design the feedback control and implement the GigaHertz bandwidth hardware. This paper presents those R&D lines and reports on the progress as it stands today. It presents preliminary results of feedback systems stabilizing the transverse intra-bunch motion, based on macro-particle simulation codes (CMAD / HeadTail) and measurement results of the beam motion when it is driven by particular excitation signals. | |||
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Slides THO1B05 [7.197 MB] | ||
THO1C06 | Recent Commissioning of High-intensity Proton Beams in J-PARC Main Ring | beam-losses, injection, proton, acceleration | 575 |
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J-PARC main ring (MR) provides high power proton beams of 200 kW to the neutrino experiment. Beam losses were well managed within capacity of collimation system. Since this beam power was achieved by shortening the repetition rate, following tunings had been applied in order to reduce the beam losses, such as improvement of tune flatness, chromaticity correction, upgrades of injection kickers, dynamic bunch-by-bunch feed-back to suppress transverse oscillation, beam loading compensation using feed-forward technique, and balancing the collimators of MR and the injection beam transport line. The dynamic bunch-by-bunch feed-back was effective to reduce the beam losses to one-tenth during injection and beginning of acceleration. With the beam loading compensation, impedance seen by the beam was significantly reduced, longitudinal oscillations were damped, and the beam power was increased over 5% without increasing the beam losses. Monitors were upgraded to find time structure and location of the beam losses, even in first several turns after each injection. In this presentation these commissioning procedures and beam dynamics simulations are shown, and our upgrade plan is discussed. | |||
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Slides THO1C06 [2.193 MB] | ||