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Status of High Power Tests of Normal Conducting Single-Cell Structures

Description: We report the results of ongoing high power tests of single-cell standing wave structures. These tests are part of an experimental and theoretical study of rf breakdown in normal conducting structures at 11.4 GHz. The goal of this study is to determine the maximum gradient possibilities for normal-conducting rf powered particle beam accelerators. The test setup consists of reusable mode launchers and short test structures powered by SLACs XL-4 klystron. The mode launchers and structures were ma… more
Date: November 4, 2011
Creator: Dolgashev, V. A.; Tantawi, S. G.; Higashi, Y. & Higo, T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Plasma Wake Excitation by Lasers or Particle Beams

Description: Plasma accelerators may be driven by the ponderomotive force of an intense laser or the space-charge force of a charged particle beam. Plasma wake excitation driven by lasers or particle beams is examined, and the implications of the different physical excitation mechanisms for accelerator design are discussed. Plasma-based accelerators have attracted considerable attention owing to the ultrahigh field gradients sustainable in a plasma wave, enabling compact accelerators. These relativistic pla… more
Date: April 1, 2011
Creator: Schroeder, Carl B.; Esarey, Eric; Benedetti, Carlo; Toth, Csaba; Geddes, Cameron & Leemans, Wim
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Coupler Studies for PBG Fiber Accelerators

Description: Photonic band gap (PBG) fiber with hollow core defects are being designed and fabricated for use as laser driven accelerators because they can provide gradients of several GeV/m for picosecond pulse lengths. We expect to produce fiber down to {lambda} = 1.5-2.0 {micro}m wavelengths but still lack a viable means for efficient coupling of laser power into such structures due to the very different character of the TM-like modes from those used in the telecom field and the fact that the defect must… more
Date: August 17, 2011
Creator: England, J.; Ng, C.; Noble, R.; Spencer, J.; Wu, Z. & Xu, D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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On scaling properties of crossing the third-order resonance in particle accelerator

Description: We study effects of charged particle beams crossing a third-order resonance in an accelerator. The distortion of invariant torus during the resonance crossing is used to set 20% emittance growth or 2.5% of trap fraction as the critical resonance strength. We find a simple scaling law for the critical resonance strength vs the tune ramp rate and the initial emittance. The scaling law can be derived by solving Hamilton's equation of motion with stationary phase condition. Such scaling law can be … more
Date: December 1, 2011
Creator: Lee, S. Y.; Pang, X.; Jing, Y.; Luo, T. & Ng, K. Y.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Novel Approach to Linear Accelerator Superconducting Magnet System

Description: Superconducting Linear Accelerators include a superconducting magnet system for particle beam transportation that provides the beam focusing and steering. This system consists of a large number of quadrupole magnets and dipole correctors mounted inside or between cryomodules with SCRF cavities. Each magnet has current leads and powered from its own power supply. The paper proposes a novel approach to magnet powering based on using superconducting persistent current switches. A group of magnets … more
Date: November 28, 2011
Creator: Kashikhin, Vladimir
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Future directions of accelerator-based NP and HEP facilities

Description: Progress in particle and nuclear physics has been closely connected to the progress in accelerator technologies - a connection that is highly beneficial to both fields. This paper presents a review of the present and future facilities and accelerator technologies that will push the frontiers of high-energy particle interactions and high intensity secondary particle beams.
Date: July 24, 2011
Creator: Roser, T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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High-Power Targets: Experience and R&D for 2 MW

Description: High-power particle production targets are crucial elements of future neutrino and other rare particle beams. Fermilab plans to produce a beam of neutrinos (LBNE) with a 2.3 MW proton beam (Project X). Any solid target is unlikely to survive for an extended period in such an environment - many materials would not survive a single beam pulse. We are using our experience with previous neutrino and antiproton production targets, along with a new series of R&D tests, to design a target that has… more
Date: March 1, 2011
Creator: Hurh, P.; Caretta, O.; Davenne, T.; Densham, C.; Loveridge, P. & Simos, N.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Radio Frequency Station - Beam Dynamics Interaction in Circular Accelerators

Description: The longitudinal beam dynamics in circular accelerators is mainly defined by the interaction of the beam current with the accelerating Radio Frequency (RF) stations. For stable operation, Low Level RF (LLRF) feedback systems are employed to reduce coherent instabilities and regulate the accelerating voltage. The LLRF system design has implications for the dynamics and stability of the closed-loop RF systems as well as for the particle beam, and is very sensitive to the operating range of accele… more
Date: March 1, 2011
Creator: Mastoridis, Themistoklis & /Stanford U., Elect. Eng. Dept. /SLAC
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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First observation of the exchange of transverse and longitudinal emittances

Description: An experimental program to demonstrate a novel phase space manipulation in which the horizontal and longitudinal emittances of a particle beam are exchanged has been completed at the Fermilab A0 Photoinjector. A new beamline, consisting of a TM{sub 110} deflecting mode cavity flanked by two horizontally dispersive doglegs has been installed. We report on the first direct observation of transverse and longitudinal emittance exchange: {l_brace}{var_epsilon}{sub x}{sup n}, {var_epsilon}{sub y}{sup… more
Date: February 1, 2011
Creator: Ruan, J.; Johnson, A. S.; Lumpkin, A. H.; Thurman-Keup, R.; Edwards, H.; Fliller, R. P. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Design of an achromatic and uncoupled medical gantry for radiation therapy

Description: We are presenting the layout and the optics of a beam line to be used as a medical gantry in radiation therapy. The optical properties of the gantry's beam line are such as to make the beam line achromatic and uncoupled. These two properties make the beam spot size, which is delivered and focused by the gantry, on the tumor of the patient, independent of the angular orientation of the gantry. In this paper we present the layout of the magnetic elements of the gantry, and also present the theore… more
Date: March 28, 2011
Creator: Tsoupas, N.; Kayran, D.; Litvinenko, V. & MacKay, W. W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The effects of realistic pancake solenoids on particle transport

Description: Solenoids are widely used to transport or focus particle beams. Usually, they are assumed as being ideal solenoids with a high axial-symmetry magnetic field. Using the Vector Field Opera program, we modeled asymmetrical solenoids with realistic geometry defects, caused by finite conductor and current jumpers. Their multipole magnetic components were analyzed with the Fourier fit method; we present some possible optimized methods for them. We also discuss the effects of 'realistic' solenoids on … more
Date: February 1, 2011
Creator: Gu, X.; Okamura, M.; Pikin, A.; Fischer, W. & Luo, Y.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Construction of AC Motor Controllers for NOvA Experiment Upgrades

Description: I have been constructing Alternating Current (AC) motor controllers for manipulation of particle beam detectors. The capability and reliability of these motor controllers are essential to the Laboratory's mission of accurate analysis of the particle beam's position. The device is moved in and out of the beam's path by the motor controller followed by the Neutrinos at the Main Injector Off-Axis {nu}{sub e} Appearance (NOvA) Experiment further down the beam pipe. In total, I built and tested ten … more
Date: August 4, 2011
Creator: Cooley, Patrick
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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