Dobrin Kaltchev

The ARIEL electron linac has been added to the TRIUMF facility as a new driver for the production of radioactive isotopes through photo-fission to complement the existing 500 MeV, H⁻ TRIUMF cyclotron. The electron beam driver is specified as a 50 MeV, 10 mA cw superconducting electron linac at 1.3 GHz. The first 30 MeV stage of the e-linac consisting of two cryomodules is completed. The paper will describe the recent commissioning and early operation results.

This paper describes time-domain simulations of singlepass transverse beam-breakup (BBU) effects in the TRIUMF/ARIEL E-linac. Using dipole-HOM parameters for the 9-cell cavity obtained with CST Microwave Studio, we evaluate the rms bunch orbit offsets at linac exit as a function of the average beam current. This allows to evaluate the effectiveness of the HOM absorbers for two different modes of machine operation.

The superconducting e-Linac project at TRIUMF requires a new nine cell elliptical cavity at 1.3 GHz of TESLA influenced design capable of providing a CW accelerating voltage of 10MV at 10mA of beam intensity. This corresponds to a challenging 100kW of beam loaded rf power and a Beam Break-up (BBU) threshold in multipass mode of Rd/Q* QL= 10MOhm. For this purpose we use two opposed CPI 60kW CW rated couplers. Another challenge is to provide HOM damping for the possibility of multi-pass ERL operation by ...

According to a theorem of Poincare, the solutions to differential equations are analytic functions of (and therefore have Taylor expansions in) the initial conditions and various parameters provided that the right sides of the differential equations are analytic in the variables, the time, and the parameters. These Taylor expansions, which provide a transfer map M between initial and final conditions, may be obtained, to any desired order, by integration of the complete variational equations. As an example of this approach, the convergence of such an expansion is investigated for the Duffing equation stroboscopic map in the vicinity of a infinite period doubling cascade and resulting strange attractor.

The LHC@Home BOINC project has provided computing capacity for numerical simulations to researchers at CERN since 2004, and has since 2011 been expanded with a wider range of applications. The traditional CERN accelerator physics simulation code SixTrack enjoys continuing volunteers support, and thanks to virtualisation a number of applications from the LHC experiment collaborations and particle theory groups have joined the consolidated LHC@Home BOINC project. This paper addresses the challenges related to traditional and virtualized applications in the BOINC environment, and how volunteer computing has been integrated into the overall computing strategy of the laboratory through the consolidated LHC@Home service. Thanks to the computing power provided by volunteers joining LHC@Home, numerous accelerator beam physics studies have been carried out, yielding an improved understanding of charged particle dynamics in the CERN Large Hadron Collider (LHC) and its future upgrades. The mai...

The Enge function can be used to parametrize any element with well-defined edges. If an element is too short, however, there is no unambiguous definition of the effective edge. We first demonstrate that very little fringe field detail is needed to obtain accurate maps even up to fifth order. Then we go on to show a simple fitting algorithm that works well for short as well as long quadrupoles. The results are true whether the quads are magnetic or electrostatic.

The method of truncated power series algebra is applied in a Mathematica code to compute the transfer map for arbitrary equations of motion describing a charged particle optical system. The code is a non-symplectic integrator - a combination between differential algebra module and a numerical solver of the equations of motion. Using the symbolic system offers some advantages, especially in the case of non-autonomous equations of motion (element with fringe-fields). An example is given - a soft-fringe map of a magnetic quadrupole.

According to a theorem of Poincare, the solutions to differential equations are analytic functions of (and therefore have Taylor expansions in) the initial conditions and various parameters providing the right sides of the differential equations are analytic in the variables, the time, and the parameters. We describe how these Taylor expansions may be obtained, to any desired order, by integration of what we call the complete variational equations. As illustrated in a Duffing equation stroboscopic map example, these Taylor expansions, truncated at an appropriate order thereby providing polynomial approximations, can well reproduce the behavior (including infinite period doubling cascades and strange attractors) of the solutions of the underlying differential equations.

Skip to main content. CERN Logo CERN Document Server. Related links. CDS; Indico; Library; Bulletin; EDMS. Main navigation links: Search; Submit; Help; Your CDS: Your alerts; Your baskets; Your searches. login. Home > Articles & Preprints > Published Articles > JINR tau-charm factory study. Information; Discussion (0); Files. Article. Report number, JINR-E9-92-259. Title, JINR tau-charm factory study.

The coherent corrections to the radiation spectrum of a relativistic electron beam, propagating along an external magnetic field are investigated. In the beam reference frame the cyclotron radiation from a hot magnetoplasma is calculated taking into account the electron correlations. The fluctuation‐dissipation theorem for the case of an equilibrium plasma is used to find the spectrum of current‐density fluctuations.

Abstract In 2008, the SPS-to-LHC transfer line operation allowed for the first time to perform beam measurements in the last part of the lines and into the LHC. Beam parameters were measured and compared with expectation. Discrepancies were observed in the dispersion matching into the LHC, and also in the vertical phase advance along the line. In 2009, extensive theoretical and simulation work was performed in order to understand the possible sources of these discrepancies.

This work is concerned with new possible hardware to produce positrons in the upgraded CESR (Cornell University, USA) linac injector by the enhanced power capacity of the converter and improved focusing of the emerging positrons. The paper describes the design of the converter which can handle 200 MeV incident beams carrying 6 kW average power. In this work it is suggested to design the quarter wave transformer (QWT) from two Helmholtz coils.

Skip to main content. CERN Logo CERN Document Server. Related links. CDS; Indico; Library; Bulletin; EDMS. Main navigation links: Search; Submit; Help; Your CDS: Your alerts; Your baskets; Your searches. login. Home > Articles & Preprints > Published Articles > Gain Calculation for the Synchrotron Radiation Free Electron Maser. Information; Discussion (0); Files. Article. Title, Gain Calculation for the Synchrotron Radiation Free Electron Maser. Author(s), Kaltchev, DI ; Perelshtejn, EA.

Abstract We have evaluated the dynamic aperture in the presence of beam-beam effects for alternative running scenarios, in particular for the commissioning and early operation of the LHC. For top energy of 7 TeV we have studied the effect of increased beta* up to beta*= 2 m and found the expected increase of dynamic aperture for a moderate loss of luminosity. We have further studied the possibility of head-on collisions with a small number of bunches at injection energy.

Abstract While the two collimation insertions in the LHC must have similar basic layouts and match to almost identical dispersion suppressors to respect the geometry of the existing tunnel, their different roles impose opposite requirements on the normalized dispersion within them. For betatron collimation it must be near zero, while for momentum collimation it must have a peak at the location of the primary collimator, immediately after the dispersion suppressor.

Page 1. Studies of transverse multi-bunch beam breakup in E-linac Dobrin Kaltchev, Richard Baartman, Yu-Chiu Chao, Philipp Kolb, Shane Koscielniak, Lia Merminga, Amiya Mitra, Vladimir Zvyagintsev TRIUMF, Vancouver BC, Canada Introduction This paper presents the results from our simulations of single-pass transverse beam-breakup (BBU) effects in E-linac [1].