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A kicker design for the rapid transfer of the electron beam between radiator beamlines in LUX

Description: I present in this paper preliminary design concepts for a fast kicker magnet and driver for the rapid transfer of the electron beam between radiator beam lines in LUX. This paper presents a feasibility study to find a roughly optimized subset of engineering parameters that would satisfy the initial design specifications of: Pulse width < 30 mu s, rise / fall time < 10 mu s, time jitter < 1ns, magnetic length < 0.5meter, gap height = 15mm, gap width = 25mm, peak field = 0.6Tesla, bend angle = 1.7 deg. for beam energy of 3.1 Gev, repetition rate = 10KHz. An H magnet core configuration was chosen. Through an iterative mathematical process employing Mathcad 11 [1] a realizable design was chosen. Peak current, Peak voltage across the coils, conductor losses due to proximity and skin effects, and basic circuit topology were investigated. Types and losses of core material were only briefly discussed. The final topology consists of two magnets in series running at 10KHz, .3Tesla, 630 amp peak current, 10 mu s pulse width, 693 Watts per coil section, driven by fast solid state switch with an energy recovery inductor.
Date: June 30, 2004
Creator: Stover, Gregory D.
Partner: UNT Libraries Government Documents Department

Transmission line analysis of beam deflection in a BPM stripline kicker

Description: In the usual treatment of impedances of beamline structures the electromagnetic response is computed under the assumption that the source charge trajectory is parallel to the propagation axis and is unaffected by the wake of the structure. For high energy beams of relatively low current this is generally a valid assumption. Under certain conditions the assumption of a parallel source charge trajectory is no longer valid and the effects of the changing trajectory must be included in the analysis. Here the usual transmission line analysis that has been applied to BPM type transverse kickers is extended to include the self-consistent motion of the beam in the structure.
Date: May 1, 1997
Creator: Caporaso, G.J.; Chen, Yu Ju & Poole, B.
Partner: UNT Libraries Government Documents Department

A Linear hybrid kicker modulator for ETA-II

Description: A new type of pulse modulator is being developed at Livermore that will rapidly split a high current electron beam into two halves, enabling each half to proceed along separate pathways. Each modulator will be capable of applying a {+-}10kV, 200A pulse onto a transmission line electrode structure with a rise time less than 10 ns, a pulse repetition frequency greater than 1 MHz, and a maximum pulse duration of 400 ns. The electrode structure, located inside the beam-transport pipe, generates an electromagnetic field that acts on part of the original beam to ``kick`` it in another direction. The true merit of this high-speed modulator will be its flexibility in pulse duration and shape. The electrodynamics involved in altering the beam`s trajectory require the modulator to generate a time-varying pulse that is precisely tailored in amplitude. Consequently, the modulator is driven by an arbitrary waveform generator and must act more as a linear amplifier than as a simple switch. The requirements of high peak power and wide analog bandwidth (about 50 MHz) will be addressed by merging a solid-state driver with an output stage of high-power vacuum tubes. Modulator development and performance data will be presented as will the issues of beam-induced voltage and transit-time isolation that are considered when driving a beam load.
Date: June 29, 1997
Creator: Buckles, R.; Davis, B. & Yen, B.
Partner: UNT Libraries Government Documents Department

The coupling impedance of the RHIC injection kicker system

Description: In this paper, results from impedance measurements on the RHIC injection kickers are reported. The kicker is configured as a {open_quotes}C{close_quotes} cross section magnet with interleaved ferrite and high-permittivity dielectric sections to achieve a travelling wave structure. The impedance was measured using the wire method in which a resistive match provides a smooth transition from the network analyzer to the reference line in the set-up. Accurate results are obtained by interpreting the forward scattering coefficient via the log-formula. The four kickers with their ceramic beam tubes contribute a Z/n = 0.22 {Omega}/ring in the interesting frequency range from 0.1 to 1 GHz, and less above. At frequencies above {approximately}100 MHZ, the impedance is ferrite dominated and not affected by the kicker terminations. Below 100 MHz, the Blumlein pulser with the {approximately}75 m feeding cables is visible in the impedance but makes no significant contribution to the results. The measurements show that the kicker coupling impedance is tolerable without the need for impedance reducing measures.
Date: July 1, 1997
Creator: Hahn, H. & Ratti, A.
Partner: UNT Libraries Government Documents Department

LHC Kicker Beam-Impedance Calculation

Description: Longitudinal and transverse beam impedances are calculated for the injection kickers designed for use in the CERN large hadron col- Iider. These combine the contributions of a ceramic beam tube with conducting stripes and a traveling-wave kicker magnet. The results show peak impedances of 1300 ohm longitudinal and 8 Mfl/m trans- verse for four units per ring.
Date: October 1, 1998
Creator: Lambertson, G.R.
Partner: UNT Libraries Government Documents Department

Electromagnetic cold-test characterization of the quad-driven stripline kicker

Description: The first kicker concept design for beam deflection was constructed to allow stripline plates to be driven; thus directing, or kicking, the electron beam into two subsequent beam lines. This quad-driven stripline kicker is an eight port electromagnetic network and consists of two actively driven plates and two terminated plates. Electromagnetic measurements performed on the bi-kicker and quad-kicker were designed to determine: (1) the quality of the fabrication of the kicker, incluidng component alignments; (2) quantification of the input feed transition regions from the input coax to the driven kicker plates; (3) identification of properties of the kicker itself without involving the effects of the electron beam; (4) coupling between a line current source and the plates of the kicker; and (5) the effects on the driven current to simulate an electron beam through the body of the kicker. Included in this are the angular variations inside the kicker to examine modal distributions. The goal of the simulated beam was to allow curved path and changing radius studies to be performed electromagnetically. The cold test results produced were then incorporated into beam models.
Date: August 14, 1998
Creator: Dunlap, J E & Nelson, S D
Partner: UNT Libraries Government Documents Department

A protype dipole septum magnet for fast high current kicker systems

Description: A dipole "septum" magnet without a material septum has been designed and tested as part of a fast beam kicker system for use in intense, electron-beam induction accelerators. This septum magnet is a simple, iron-based electromagnet with two static, oppositely oriented dipole field regions used to provide further separation of beam centroids given a small angle kick by a fast beam kicker. The magnet geometry includes removable pole pieces to allow experimental flexibility. Field errors experienced by the beam depend crucially on the magnitude of the initial kick that provides displacement of the beam centroids from the transition region between the two dipole field regions. Results of simulations are reported.
Date: March 29, 1999
Creator: Wang, L F; Caporaso, G J; Chen, Y J; Lund, S M; Poole, B R & Brown, T F
Partner: UNT Libraries Government Documents Department

Pulsed magnetic field measurement using a ferrite waveguide in a phase bridge circuit

Description: There are several standard methods used for measuring pulsed magnetic fields. However the induction or Hall probe methods have limited bandwidth and experience reflection problems. The integrated magnetic field can only be found by measuring along the entire length of the magnet. Problems with reflections, noise and bandwidth will limit the accuracy of measurement. Presented in the following paper is a method for measuring pulsed fields without the typical noise errors and bandwidth limitations. This paper will describe a phase bridge network that relies upon the permeability of a ferrite waveguide to accurately measure the integrated field of a Main Injector kicker magnet. The authors present some data taken with the system, a first pass at the analysis of this data, and discuss some possible design variations.
Date: July 1, 2002
Creator: Colestock, William A Pellico and Patrick
Partner: UNT Libraries Government Documents Department

The RHIC injection kicker

Description: Beam transfer from the AGS to RHIC is performed in single-bunch mode. Close spacing of the bunches in the collider requires an injection kicker with a rise time of <90 nsec, suggesting adoption of a travelling wave structure. The required vertical kick of 0.186 t{center_dot}m is provided by 4 magnets, each 1.12 m long with a 48.4 x 48.4 mm aperture and operated at 1.6 kA. The kicker is constructed as a {open_quotes}C{close_quotes} cross section magnet, in which ferrite and high-permittivity dielectric sections alternate. The dielectric blocks provide the capacity necessary for the nominally 25 {Omega} characteristic impedance of the travelling wave structure, but impose the practical limit on the peak voltage, and thus current, achievable. Computer studies to minimize local electric field enhancements resulted in a configuration capable of holding {approximately} 50 kV, with adequate safety margin over the nominal 40 kV. Equivalent circuit analysis indicated the possibility of lowering the nominal voltage by operating mismatched into 20 {Omega} terminations without degrading the pulse shape. In this paper, the experience gained in the fabrication of the production units and the results from various single-unit tests and operation of four kickers with beam in the {open_quotes}Sextant Test{close_quotes} are reported.
Date: July 1, 1997
Creator: Hahn, H.; Tsoupas, N. & Tuozzolo, J.E.
Partner: UNT Libraries Government Documents Department

Magnet design concepts for the 100 MeV isotope production facility

Description: The North Port Target Facility proposal includes a 100 MeV beam line to be is built at the LANSCE accelerator. In developing cost and schedule estimates for the proposal the greatest uncertainties are associated with the kicker magnet that is needed to divert portions of the beam into the new beam line. This magnet must fit into a rigidly defined space within the transition region of the existing accelerator and must operate in synchrony with the current accelerator operations systems, In addition, it must not degrade the beam qualify when beam is directed to other areas of the complex. Because of these constraints the magnet must be specifically designed and built for this intended application. We have produced conceptual designs of a kicker-magnet and power supply that will meet all of the design requirements. The power supply design is based on a working design for the RIKI kicker magnet that switches 800 MeV beam into the PSR. This report presents the kicker-magnet and power-supply designs and cost and schedule estimates for incorporation into the EP facility proposal. The feasibility of various design alternatives are briefly discussed.
Date: October 7, 1996
Creator: Wadlinger, E.A.; Merrill, F.E. & Power, J.F.
Partner: UNT Libraries Government Documents Department

Test of very fast kicker for TESLA damping ring

Description: We describe a very fast kicker with unique combination of high repetition rate and short pulse width. Constructionally, the device is a symmetrical counter traveling wave stripline kicker fed by semiconductor high-voltage pulse generator. Experimentally tested kicker has a full pulse width of about 7 ns, 1.4 MHz repetition rate and maximum kick strength of the order of 3 G{center_dot}m. Recent achievements in high-voltage semiconductor field-effect transistors (FET) technology and goal-specific optimization of the kicker parameters allow many-fold increase of the strength, and the kicker can be very useful tool for bunch-by-bunch injection/extraction and other accelerator applications. 4 refs., 3 figs.
Date: April 1, 1997
Creator: Grishanov, B.I.; Podgorny, F.V.; Ruemmler, J. & Shiltsev, V.D.
Partner: UNT Libraries Government Documents Department

The PEP-II abort kicker system

Description: The PEP-II project has two storage rings. The HER (High Energy Ring) has up to 1.48 A of electron beam at 9 GeV, and the LER (Low Energy Ring) has up to 2.14 A of positron beam at 3.1 GeV. To protect the HER and LER beam lines in the event of a ring component failure, each ring has an abort kicker system which directs the beam into a dump when a failure is detected. Due to the high current of the beams, the beam kick is tapered from 100% to 80% in 7.33 uS (the beam transit time around the time). This taper distributes the energy evenly across the window which separates the ring from the beam dump such that the window is not damaged. The abort kicker trigger is synchronized with the ion clearing gap of the beam allowing for the kicker field to rise from 0-80% in 370 nS. This report discusses the design of the system controls, interlocks, power supplies, and modulator.
Date: July 1, 1997
Creator: Lamare, J de; Donaldson, A. & Kulikov, A. Lipari, J.
Partner: UNT Libraries Government Documents Department

Impact of the LHC beam abort kicker prefire on high luminosity insertion and CMS detector performance

Description: The effect of possible accidental beam loss in LHC on the IP5 insertion elements and CMS detector is studied via realistic Monte Carlo simulations. Such beam loss could be the consequence of an unsynchronized abort or � in worst case � an accidental prefire of one of the abort kicker modules. Simulations with the STRUCT code show that this beam losses would take place in the IP5 inner and outer triplets. MARS simulations of the hadronic and electro-magnetic cascades induced in such an event indicate severe heating of the inner triplet quadrupoles. In order to protect the IP5 elements, two methods are proposed: a set of shadow collimators in the outer triplet and a prefired module compensation using a special module charged with an opposite voltage (antikicker). The remnants of the accidental beam loss entering the experimental hall have been used as input for FLUKA simulations in the CMS detector. It is shown that it is vital to take measures to reliably protect the expensive CMS tracker components.
Date: April 13, 1999
Creator: A.I. Drozhdin, N.V. Mokhov and M. Huhtinen
Partner: UNT Libraries Government Documents Department

The PEP II injection kicker system

Description: PEP II or the B Factory consists of two asymmetric storage rings. The injection energy for electrons is 9 GeV, while that for positrons is 3.1 GeV. The bend angle into the high energy ring (HER) is 0.35 m-rad, and the angle into the low energy ring (LER) is 0.575 m-rad. The magnetic length for the HER kicker is 0.85 m, and 0.55 m for the LER kicker. The field produced by the magnet is therefore 123.5 G for the HER, and 132 G for the LER. Each ring has a kicker magnet upstream of the injection line which is used to distort the orbit of the stored beam. An identical magnet downstream of the injection line is used to restore the orbit of the stored beam and inject the incoming beam. The two magnets are driven in parallel by the modulator. The apeture of the magnets is 3.86x3.46 cm (HxV). Therefore the current required to drive the HER is 863 A, while for the LER it is 756 A. The inductance of the magnet is approximately 1.4 uH/m. The current pulse is a critically damped sinusoid with a rise time of less than 300 ns. A kicker system has been designed which can be used for injection of both beams by varying the charge of voltage. The modulator uses a conjugate circuit to match the impedance of the magnet, and coupling to the beam chamber.
Date: July 1, 1997
Creator: Pappas, G.C.; Donaldson, A.R. & Williams, D.
Partner: UNT Libraries Government Documents Department

ETA-II experiments for determining advanced radiographic capabilities of induction linacs

Description: LLNL has proposed a multi-pulsed, multi-line of sight radiographic machine based on induction linac technology to be the core of the advanced hydrotest facility (AHF) being considered by the Department of Energy. In order to test the new technologies being developed for AHF we have recommissioned the Experimental Test Accelerator (ETA II). We will conduct our initial experiments using kickers and large angle bending optics at the ETA II facility. Our current status and our proposed experimental schedule will be presented.
Date: May 1, 1997
Creator: Weir, J.T.; Caporaso, G.J.; Clark, J.C.; Kirbie, H.C.; Chen, Y.-J.; Lund, S.M. et al.
Partner: UNT Libraries Government Documents Department

Beam injection into RHIC

Description: During the RHIC sextant test in January 1997 beam was injected into a sixth of one of the rings for the first time. The authors describe the injection zone and its bottlenecks. They report on the commissioning of the injection system, on beam based measurements of the kickers and the application program to steer the beam.
Date: July 1, 1997
Creator: Fischer, W.; Hahn, H.; MacKay, W.W.; Satogata, T.; Tsoupas, N. & Zhang, W.
Partner: UNT Libraries Government Documents Department

Equivalent circuit analysis of the RHIC injection kicker

Description: The RHIC injection kicker is built as a traveling wave structure in order to assure the required 95 nsec risetime in the deflection strength. The kicker is constructed from 14 cells, each 7.5 cm long, with alternating ferrite and high-permittivity dielectric sections. The cell structure permits an analysis of the electrical properties of the kicker using lumped L, C, and R circuit elements. Their values are obtained directly from impedance measurements of the full-length kicker, the inductance and shunt capacitance values by measuring the input impedance at 1 MHz with the output shorted and open, respectively. A lossy series resonance circuit in each cell is found to reproduce the measured input impedance of the terminated kicker up to {approximately}100 MHz. The validity of the equivalent circuit was confirmed by comparing the measured output current pulse shape time with that computed by the P-Spice program.
Date: July 1, 1997
Creator: Hahn, H. & Ratti, A.
Partner: UNT Libraries Government Documents Department

Correction of closed orbit distortions in the horizontal direction

Description: Many computer programs with a variety of algorithms exist for controlling the closed orbit in synchrotrons. The scope of this note is rather modest in comparison. Based on a simple model, a study has been made to find out statistically how much kick angle is needed by each steering element and how much residual closed orbit deviation should be expected when the closed orbit is steered to go through the center of seven position monitors (M{sub 2} through M{sub 8}) in each cell. Seven independent kicks are supplied by two trim dipoles B{sub U} and B{sub D}, and six steering elements (H{sub 1} through H{sub 6}) with H{sub 3} and H{sub 4} assumed to have the same kick angle. If it is necessary to remove H{sub 3} to make a space there for a correction skew quadrupole (in every other cell), the kick angle of H{sub 4} would have to be doubled.
Date: February 1, 1988
Creator: Ohnuma, S.
Partner: UNT Libraries Government Documents Department

Linear induction accelerator approach for advanced radiography

Description: Recent advances in induction accelerator technology make it possible to envision a single accelerator that can serve as an intense, precision multiple pulse x-ray source for advanced radiography. Through the use of solid-state modulator technology repetition rates on the order of 1 MHz can be achieved with beam pulse lengths ranging from 200 ns to 2 {micro}secs. By using fast kickers, these pulses may be sectioned into pieces which are directed to different beam lines so as to interrogate the object under study from multiple lines of sight. The ultimate aim is to do a time dependent tomographic reconstruction of a dynamic object. The technology to accomplish these objectives along with a brief discussion of the experimental plans to verify it will be presented.
Date: May 1, 1997
Creator: Caporaso, G.J.
Partner: UNT Libraries Government Documents Department

RHIC injection kicker impedance

Description: The longitudinal impedance of the RHIC injection kicker is measured using the wire method up to a frequency of 3 GHz. The mismatch between the 50 ohm cable and the wire and pipe system is calibrated using the TRL calibration algorithm. Various methods of reducing the impedance, such as coated ceramic pipe and copper strips are investigated.
Date: May 1, 1995
Creator: Mane, V.; Peggs, S.; Trbojevic, D. & Zhang, W.
Partner: UNT Libraries Government Documents Department

Multi-pulse extraction from Los Alamos Proton Storage Ring for radiographic applications

Description: In Proton Radiography, one of the goals is a motion picture of a rapidly moving object. The Los Alamos Proton Storage Ring (PSR) in its normal operating mode, delivers a single pulse approximately 120 ns wide (fwhm). In development runs at the PSR, the authors successfully demonstrated operation of a technique to deliver two pulses, each 40 nsec wide, with adjustable spacing.
Date: August 1, 1997
Creator: Thiessen, H.A.; Neri, F.; Rust, K. & Redd, D.B.
Partner: UNT Libraries Government Documents Department