Beam Dynamics and Accelerating Cavity Electrodynamics’ Simulation of CW 2 Mev Proton RFQ (original) (raw)

Beam Dynamics Simulations and Code Comparison for a New CW RFQ Design

2016

Research and development of CW applications is an important step in RFQ design. The RF potential should be limited by 1.3-1.5 of Kilpatrick criterion for the CW mode. A 2 MeV RFQ is under development for the compact CW research proton accelerator, as well as for planned driver linac in Russia. The maximum beam current is fixed to 10 mA; the operating frequency has been set to 162 MHz. The new RFQ linac design will be presented and beam dynamics simulation results will be discussed. Calculations of the beam dynamics are provided using the codes BEAMDULAC (developed at MEPhI for linac design) and DYNAMION. A comparison of the software performance is presented.

Exploring the beam parameter space of a CW RFQ proton accelerator

Proceedings of the 1989 IEEE Particle Accelerator Conference, . 'Accelerator Science and Technology, 1989

RFQl> a 100% duty factor radiofrequency quadrupole to accelerate 75 mA of protons to a final energy of C.6 MeV, is a test bed for a wide range of high power RFQ experiments. First beam was accelerated in RFQl in July 1988 and an experimental program to investigate the beam parameter space of the machine was started. With the initial 3-beamlet ion source adjusted to deliver 5 mA to the RFQ, only 35% of the beam was captured and accelerated to design energy. Changing to a lower emittance single-beamlet source, transmission improved to almost 80% with over 6 mA CY accelerated. CW rf conditioning experience with the RFQ is described and results of the experiments compared with PARMTEQ and TRANSPORT calculations.

Performance of the CERN Linac 2 with a high intensity proton RFQ

1994

operating experience of Linac 2 with its new injector is also described. linac and how they compare with beam dynamics simulations. The first Linac 2, the measurements of beam intensity and quality at the output of the simulations and measurements to determine the new parameter set-up for This paper covers the RFQ2 installation and running-in at the linac, the Large Hadron Collider.

Development and beam test of a continuous wave radio frequency quadrupole accelerator

Physical Review Special Topics - Accelerators and Beams, 2012

The front end of any modern ion accelerator includes a radio frequency quadrupole (RFQ). While many pulsed ion linacs successfully operate RFQs, several ion accelerators worldwide have significant difficulties operating continuous wave (CW) RFQs to design specifications. In this paper we describe the development and results of the beam commissioning of a CW RFQ designed and built for the National User Facility: Argonne Tandem Linac Accelerator System (ATLAS). Several innovative ideas were implemented in this CW RFQ. By selecting a multisegment split-coaxial structure, we reached moderate transverse dimensions for a 60.625-MHz resonator and provided a highly stabilized electromagnetic field distribution. The accelerating section of the RFQ occupies approximately 50% of the total length and is based on a trapezoidal vane tip modulation that increased the resonator shunt impedance by 60% in this section as compared to conventional sinusoidal modulation. To form an axially symmetric beam exiting the RFQ, a very short output radial matcher with a length of 0:75 was developed. The RFQ is designed as a 100% oxygen-free electronic (OFE) copper structure and fabricated with a two-step furnace brazing process. The radio frequency (rf) measurements show excellent rf properties for the resonator, with a measured intrinsic Q equal to 94% of the simulated value for OFE copper. An O 5þ ion beam extracted from an electron cyclotron resonance ion source was used for the RFQ commissioning. In off-line beam testing, we found excellent coincidence of the measured beam parameters with the results of beam dynamics simulations performed using the beam dynamics code TRACK, which was developed at Argonne. These results demonstrate the great success of the RFQ design and fabrication technology developed here, which can be applied to future CW RFQs.

THE RADIOFREQUENCY QUADRUPOLE ACCELERATOR FOR THE LINAC4

The first stage of acceleration in Linac4, the new 160 MeV CERN H -injector, is a 352 MHz, 3-m long Radiofrequency Quadrupole (RFQ) Accelerator. The RFQ will capture a 70 mA, 45 keV beam from the RF source and accelerate it to 3 MeV, an energy suitable for chopping and injecting the beam in a conventional Drift Tube Linac. Although the RFQ will be initially operated at low duty cycle (0.1%), its design is compatible with higher duty cycle (10%) as the front-end for a possible high-intensity upgrade of the CERN linac facility. The RFQ will be of brazed-copper construction and will be built and assembled at CERN. Beam dynamics design allows for a compact structure made of a single resonant unit. Field symmetry is ensured by fixed tuners placed along the structure. In this paper we present the RF and mechanical design, the beam dynamics and the sensitivity to fabrication and to RF errors.

Beam dynamics studies of the 8 GeV Linac at FNAL

2008

The proposed 8-GeV proton driver (PD) linac at FNAL includes a front end up to 420 MeV operating at 325 MHz and a high energy section at 1300 MHz. A normal conducting RFQ and short CH type resonators are being developed for the initial acceleration of the H-minus or proton beam up to 10 MeV. From 10 MeV to 420 MeV, the voltage gain is provided by superconducting (SC) spoke-loaded cavities. In the high-energy section, the acceleration will be provided by the International Linear Collider (ILC)-style SC elliptical cell cavities. To employ existing, readily available klystrons, an RF power fan out from high-power klystrons to multiple cavities is being developed. The beam dynamics simulation code TRACK, available in both serial and parallel versions, has been updated to include all known H-minus stripping mechanisms to predict the exact location of beam losses. An iterative simulation procedure is being developed to interact with a transient beam loading model taking into account RF fe...

Beam test of a new radio frequency quadrupole linac for the Japan Proton Accelerator Research Complex

Physical Review Special Topics - Accelerators and Beams, 2014

We performed a beam test of a new radio frequency quadrupole linac (RFQ III) for the beam current upgrade of the Japan Proton Accelerator Research Complex. First, the conditioning of RFQ III was conducted, and after 20 h of conditioning, RFQ III became very stable with a nominal peak power and duty factor of 400 kW and 1.5%, respectively. An off-line beam test was subsequently conducted before installation in the accelerator tunnel. The transmission, transverse emittance, and energy spread of the 50-mA negative hydrogen beam from RFQ III were measured and compared with simulation results. The experiment and simulation results showed good agreement; therefore, we conclude that the performance of RFQ III conforms to its design.

Beam Dynamics Design of a 162.5 MHz Superconducting RFQ Accelerator

2021

Superconducting(SC) RFQ has lower power consumption, larger aperture and higher accelerating gradient than room temperature RFQ. We plan to design a 162.5MHz SC RFQ to accelerate the 30 mA proton beams from 35 keV to 2.5 MeV, which will be used as a neutron source for BNCT and neutron imaging project. At an inter-vane voltage of 180kV, the beam dynamics design was carried out with acceptable peak surface electric field, high transmission efficiency, and relatively short cavity length.

3D Electromagnetic/PIC Simulations for a Novel RFQ/RFI Linac Design

2019

Using the commercial software VSim 9, a highly parallelized particle-in-cell/finite difference time-domain modeling code, the performance of an existing novel RFQ/RFI linac structure designed by Ion Linac Systems is evaluated. This effort is aimed towards having an up to date full 3D start-to-end simulation of the accelerator system, which does not exist currently. The structure used is an efficient 200-MHz, 2.5-MeV, CW-RFQ/RFI proton linac. The methods employed in VSim for modelling and parameter setup are presented, along with the simulation procedures for both the Electromagnetic and PIC solver. The important figures of merit for the structure are given including the Q-factor, field distributions, shunt impedance, and important beam properties. These are then contrasted with the initial design values and analytical calculations.

Physics design of rod type proton Radio Frequency Quadrupole linac

AAA: A Radio Frequency Quadrupole (RFQ) linac delivering 800 keV, 5 mA protons has been designed. It is envisaged as first injector of the proton driver that will be used for production of proton-rich radioactive beams in the proposed ANURIB facility. The option of rod-type structure at frequency of 80 MHz has been chosen owing to ease of mechanical fabrications and to avoid detrimental nearby dipole modes present in vane type structure. Optimization of parameters has been carried out for a viable length and power of RFQ in order to avoid any infrastructural complexity. Conventional method of keeping focusing factor and vane voltage constant along the length of RFQ has been adopted. Results of detailed beam dynamics and RF structure design, space charge induced effects and corroborative particle tracking with realistic 3D fields of modulated vane has been presented.