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in creator/contributor: "Ben-Zvi, Ilan"

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Numerical simulation of a short RFQ resonator using the MAFIA codes

The electrical characteristics of a short (2{beta}{lambda}=0.4 m) resonator with large modulation (m=4) have been studied using the three dimensional codes, MAFIA. The complete resonator, including the modulated electrodes and a complex support structure, has been simulated using {approximately} 350,000 mesh points. Important characteristics studied include the resonant frequency, electric and magnetic fields distributions, quality factor and stored energy. The results of the numerical simulati… more

Date: January 1, 1991

Creator: Wang, H.; Ben-Zvi, Ilan; Jain, A.; Paul, P. (State Univ. of New York, Stony Brook, NY (United States). Dept. of Physics) & Lombardi, A. (Istituto Nazionale di Fisica Nucleare, Legnaro (Italy). Lab. Nazionale di Legnaro)

Item Type: Article

Partner: UNT Libraries Government Documents Department

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The Fresh-Bunch' technique in FELs

The 'Fresh Bunch' technique is being proposed as a method of increasing the gain and power of FEL amplifiers in which the length of the optical radiation pulse is shorter than the length of the electron bunch. In multi-stage FEL, electron beam energy spread is increased by the FEL interaction in the early stages. In the 'Fresh Bunch' technique, the low energy spread of the electron beam is recovered by shifting the radiation pulse to an undisturbed part of the electron bunch, thus improving the… more

Date: January 1, 1991

Creator: Ben-Zvi, Ilan; Yang, K. M. & Yu, L. H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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A bulk niobium superconducting quarter wave resonator

A bath-cooled all-niobium 160 MHz quarter wave resonator prototype was constructed and tested. The objective of this research has been the development of a high performance accelerating element with {beta}{sub opt} {approx equal} 0.11 for the ALPI linac at the Laboratori Nazionali di Legnaro. The design of this resonator was based upon a previous 150 MHz model, with minor changes due to the different frequency and to modified welding procedure. An accelerating field of 5 MV/m was achieved at a … more

Date: January 1, 1990

Creator: Ben-Zvi, Ilan; Chiaveri, E.; Elkonin, B. V.; Facco, A. & Sokolowski, J. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Proposed uv-FEL user facility at BNL

The NSLS at Brookhaven National Laboratory is proposing the construction of a UV-FEL operating in the wavelength range from visible to 750{Angstrom}. Nano-Coulomb electron pulses will be generated at a laser photo-cathode RF gun at a repetition rate of 10 KHz. The 6 ps pulses will be accelerated to 250 MeV in a superconducting linac. The FEL output will serve four stations with independent wavelength tuning, using two wigglers and two rotating mirror beam switches. Seed radiation for the FEL am… more

Date: January 1, 1991

Creator: Ben-Zvi, Ilan; Di Mauro, L. F.; Krinsky, S.; White, M. G.; Yu, L. H.; Batchelor, K. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Theoretical analysis of iron-bore superconducting undulators

The unavoidable undulator field errors due to machining tolerances of the yokes lead to a reduction of the gain in comparison with the case computed with an ideally perfect undulator. We describe a mathematical model of errors in iron-dominated micro-undulators introduced by manufacturing tolerances. Explicit expressions for the perturbation fields are derived. We use these fields to calculate the first, second and phase integrals describing the effects on the electron trajectory. We conclude t… more

Date: January 1, 1991

Creator: Ben-Zvi, Ilan; Fernow, R.; Gallardo, J.; Ingold, G.; Sampson, W. & Woodle, M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Design of a high-brightness, high-duty factor photocathode electron gun

The proposed UV-FEL user's facility at Brookhaven National Laboratory will require a photocathode gun capable of producing short (< 6 psec) bunches of electrons in high repetition rates (5 kHz), low energy spread (< 1.5.%), a peak current of 300 A (after compression) and a total bunch charge of up to 2 nC. At the highest charge the normalized transverse emittance should be less than 7 {pi} mm-mrad. We are presently designing a gun that is expected to exceed these requirements. This gun will con… more

Date: September 1, 1991

Creator: Lehrman, I. S.; Birnbaum, I. A.; Fixler, S. Z.; Heuer, R. L.; Siddiqi, S.; Sheedy, E. (Grumman Corp., Princeton, NJ (United States)) et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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A microwiggler Free-Electron Laser at the Brookhaven Accelerator Test Facility

We report the design and status of an FEL experiment at the Brookhaven National Laboratory Accelerator Test Facility. A 50 MeV high brightness electron beam will be utilized for an oscillator experiment in the visible wavelength region. The microwiggler to be used is a superferric planar undulator with a 0.88 cm period, 60 cm length and K = 0.35. The optical cavity is a 368 cm long stable resonator with broadband dielectric coated mirrors. 8 refs., 2 figs., 4 tabs.

Date: September 26, 1989

Creator: Batchelor, K.; Ben-Zvi, Ilan; Fernow, R.; Gallardo, J.; Kirk, H.; Pellegrini, C. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Resonator design for a visible wavelength free-electron laser (*)

Design requirements for a visible wavelength free-electron laser being developed at the Accelerator Test Facility at Brookhaven National Laboratory are presented along with predictions of laser performance from 3-D numerical simulations. The design and construction of the optical resonator, its alignment and control systems are also described. 15 refs., 8 figs., 4 tabs.

Date: January 1, 1990

Creator: Bhowmik, A.; Lordi, N. (Rockwell International Corp., Canoga Park, CA (United States). Rocketdyne Div.); Ben-Zvi, Ilan & Gallardo, J. (Brookhaven National Lab., Upton, NY (United States))

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Status of the SUNY superconducting RFQ

A RFQ resonator is presently being developed at SUNY. This resonator is a prototype for a chain of six short ({approximately}0.5m long), superconducting (Pb plated Cu), 50 MHz resonators designed to accelerate beam from {beta} = 0.01 to 0.05. The chain accepts a prebunched beam to save on superconducting length. The resonators are of four-rods type with vane-like electrodes. The prototype resonator is designed to accelerate ions of q/A = 1/6 from {beta} = 0.030 to 0.036, operating at a peak sur… more

Date: January 1, 1991

Creator: Jain, A.; Ben-Zvi, Ilan; Paul, P.; Wang, H. (Brookhaven National Lab., Upton, NY (United States)) & Lombardi, A. (Istituto Nazionale di Fisica Nucleare, Legnaro (Italy). Lab. Nazionale di Legnaro)

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Status of the visible Free-Electron Laser at the Brookhaven Accelerator Test Facility

The 500 nm Free-Electron Laser (ATF) of the Brookhaven National Laboratory is reviewed. We present an overview of the ATF, a high-brightness, 50-MeV, electron accelerator and laser complex which is a users' facility for accelerator and beam physics. A number of laser acceleration and FEL experiments are under construction at the ATF. The visible FEL experiment is based on a novel superferric 8.8 mm period undulator. The electron beam parameters, the undulator, the optical resonator, optical and… more

Date: January 1, 1991

Creator: Batchelor, K.; Ben-Zvi, Ilan; Fernow, R. C.; Fisher, A. S.; Friedman, A.; Gallardo, J. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Geometric optimization of the 56 MHz SRF cavity and its frequency table

It is essential to know the frequency of a Superconducting Radio Frequency (SRF) cavity at its 'just being fabricated' stage because frequency is the key parameter in constructing the cavity. In this paper, we report our work on assessing it. We can estimate the frequency change from stage to stage theoretically and/or by simulation. At the operating stage, the frequency can be calculated accurately, and, from this value, we obtain the frequencies at other stages. They are listed in a table tha… more

Date: October 1, 2008

Creator: Chang, X. & Ben-Zvi, Ilan

Item Type: Report

Partner: UNT Libraries Government Documents Department

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The polarized SRF gun experiment.

RF electron guns are capable of producing electron bunches with high brightness, which outperform DC electron guns and may even be able to provide electron beams for the ILC without the need for a damping ring. However, all successful existing guns for polarized electrons are DC guns because the environment inside an RF gun is hostile to the GaAs cathode material necessary for polarization. While the typical vacuum pressure in a DC gun is better than 10{sup -11} torr the vacuum in an RF gun is … more

Date: September 10, 2007

Creator: Kewisch, J.; Ben-Zvi, Ilan; Rao, T.; Burrill, A.; Pate, D.; Grover, R. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Feasibility of Electron Cooling for Low-Energy RHIC Operation

A concrete interest in running RHIC at low energies in a range of 2.5-25 GeV/nucleon total energy of a single beam has recently emerged. Providing collisions in this energy range, which in the RHIC case is termed 'low-energy' operation, will help to answer one of the key questions in the field of QCD about existence and location of a critical point on the QCD phase diagram. However, luminosity projections are relatively low for the lowest energy points of interest. Luminosity improvement can be… more

Date: April 1, 2008

Creator: Fedotov, A.; Ben-Zvi, Ilan; Chang, X.; Kayran, D.; Litvinenko, V.; Pozdeyev, E. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Thermal Emittance Measurement Design for Diamond Secondary Emission

Thermal emittance is a very important characteristic of cathodes. A carefully designed method of measuring the thermal emittance of secondary emission from diamond is presented. Comparison of possible schemes is carried out by simulation, and the most accessible and accurate method and values are chosen. Systematic errors can be controlled and maintained at small values, and are carefully evaluated. Aberration and limitations of all equipment are taken into account.

Date: June 25, 2007

Creator: Wu, Q.; Ben-Zvi, Ilan; Burrill, A.; Chang, X.; Kayran, D.; Rao, T. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Multipacting Simulation Study for 56 MHz Quarter Wave Resonator using 2D Code

A beam excited 56 MHz Radio Frequency (RF) Niobium Quarter Wave Resonator (QWR) has been proposed to enhance RHIC beam luminosity and bunching. Being a RF cavity, multipacting is expected; therefore an extensive study was carried out with the Multipac 2.1 2D simulation code. The study revealed that multipacting occurs in various bands up to peak surface electric field 50 kV/m and is concentrated mostly above the beam gap and on the outer conductor. To suppress multipacting, a ripple structure w… more

Date: January 2, 2009

Creator: Naik, D. & Ben-Zvi, Ilan

Item Type: Report

Partner: UNT Libraries Government Documents Department

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High gain FEL amplification of charge modulation caused by a hadron

In scheme of coherent electron cooling (CeC) [1,2], a modulation of electron beam density induced by a copropagation hadron is amplified in high gain FEL. The resulting amplified modulation of electron beam, its shape, form and its lethargy determine number of important properties of the coherent electron cooling. In this talk we present both analytical and numerical (using codes RON [3] and Genesis [4]) evaluations of the corresponding Green functions. We also discuss influence of electron bea… more

Date: August 24, 2008

Creator: Litvinenko, V.; Ben-Zvi, Ilan; Hao, Y.; Kayran, D.; Pozdeyev, E.; Wang, G. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Progress on the High Current Superconducting Injector and Energy Recovery Linac at BNL

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Date: November 17, 2008

Creator: Ben-Zvi, Ilan

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Status of the R&D towards electron cooling of RHIC

The physics interest in a luminosity upgrade of RHIC requires the development of a cooling-frontier facility. Detailed calculations were made of electron cooling of the stored RHIC beams. This has been followed by beam dynamics simulations to establish the feasibility of creating the necessary electron beam. The electron beam accelerator will be a superconducting Energy Recovery Linac (ERL). An intensive experimental R&D program engages the various elements of the accelerator, as described … more

Date: June 1, 2007

Creator: Ben-Zvi, Ilan; Alduino, J.; Barton, D.; Beavis, D.; Blaskiewicz, M.; Brennan, J. M. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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VORPAL simulations relevant to coherent electron cooling

Coherent electron cooling (CEC) [1] combines the best features of electron cooling and stochastic cooling, via free-electron laser technology [2], to offer the possibility of cooling high-energy hadron beams with order-of-magnitude shorter cooling times. Many technical difficulties must be resolved via full-scale 3D simulations, before the CEC concept can be validated experimentally. VORPAL is the ideal code for simulating the modulator and kicker regions, where the electron and hadron beams wi… more

Date: June 23, 2008

Creator: Bell, G.; Bruhwiler, D.; Sobol, A.; Ben-Zvi, Ilan; Litvinenko, V. & Derbenev, Y.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Diamond Amplified Photocathodes

High-average-current linear electron accelerators require photoinjectors capable of delivering tens to hundreds of mA average current, with peak currents of hundreds of amps. Standard photocathodes face significant challenges in meeting these requirements, and often have short operational lifetimes in an accelerator environment. We report on recent progress toward development of secondary emission amplifiers for photocathodes, which are intended to increase the achievable average current while … more

Date: November 26, 2007

Creator: Smedley, J.; Ben-Zvi, Ilan; Bohon, J.; Chang, X.; Grover, R.; Isakovic, A. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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COMPASS, the COMmunity Petascale project for Accelerator Science and Simulation, a board computational accelerator physics initiative

Accelerators are the largest and most costly scientific instruments of the Department of Energy, with uses across a broad range of science, including colliders for particle physics and nuclear science and light sources and neutron sources for materials studies. COMPASS, the Community Petascale Project for Accelerator Science and Simulation, is a broad, four-office (HEP, NP, BES, ASCR) effort to develop computational tools for the prediction and performance enhancement of accelerators. The tools… more

Date: July 16, 2007

Creator: Cary, J. R.; Spentzouris, P.; Amundson, J.; McInnes, L.; Borland, M.; Mustapha, B. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Recent Progress on the Diamond Amplified Photo-Cathode Experiment.

We report recent progress on the Diamond Amplified Photo-cathode (DAP). The use of a pulsed electron gun provides detailed information about the DAP physics. The secondary electron gain has been measured under various electric fields. We have achieved gains of a few hundred in the transmission mode and observed evidence of emission of electrons from the surface. A model based on recombination of electrons and holes during generation well describes the field dependence of the gain. The emittance… more

Date: June 25, 2007

Creator: Chang,X.; Ben-Zvi, Ilan; Burrill, A.; Grimes, J.; Rao, T.; Segalov, Z. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Engineering Design and Fabrication of an Ampere-Class Superconducting Photocathode Electron Gun

Over the past three years, Advanced Energy Systems and Brookhaven National Laboratory (BNL) have been collaborating on the design of an Ampere- class superconducting photocathode electron gun. BNL performed the physics design of the overall system and RF cavity under prior programs. Advanced Energy Systems (AES) is currently responsible for the engineering design and fabrication of the electron gun under contract to BNL. We will report on the engineering design and fabrication status of the sup… more

Date: November 17, 2008

Creator: Ben-Zvi, Ilan

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Summary of the Mini BNL/LARP/CARE-HHH Workshop on Crab Cavities for the LHC (LHC-CC08)

The first mini-workshop on crab compensation for the LHC luminosity upgrade (LHC-CC08) was held February 24-25, 2008 at the Brookhaven National Laboratory. A total of 35 participants from 3 continents and 15 institutions from around the world participated to discuss the exciting prospect of a crab scheme for the LHC. If realized it will be the first demonstration in hadron colliders. The workshop is organized by joint collaboration of BNL, US-LARP and CARE-HHH. The enormous interest in the subj… more

Date: May 1, 2008

Creator: Ben-Zvi, Ilan; Calaga, R. & Zimmermann, F.

Item Type: Report

Partner: UNT Libraries Government Documents Department