Download or read book THE RF SYSTEM DESIGN FOR THE SPALLATION NEUTRON SOURCE written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Spallation Neutron Source (SNS) accelerator includes a nominally 1000 MeV, 2 mA average current linac consisting of a radio frequency quadrapole (RFQ), drift tube linac (DTL), coupled cavity linac (CCL), a medium and high beta super conducting (SC) linac, and two buncher cavities for beam transport to the ring. Los Alamos is responsible for the RF systems for all sections of the linac. The SNS linac is a pulsed proton linac and the RF system must support a 1 msec beam pulse at up to a 60 Hz repetition rate. The RFQ and DTL utilize seven, 2.5 MW klystrons and operate at 402.5 MHz. The CCL, SC, and buncher cavities operate at 805 MHz. Six, 5 MW klystrons are utilized for the CCL and buncher cavities while eighty-one 550 kW klystrons are used for the SC cavities. All of the RF hardware for the SNS linac is currently in production. This paper will present details of the RF system-level design as well as specific details of the SNS RF equipment. The design parameters will be discussed. One of the design challenges has been achieving a reasonable cost with the very large number of high-power klystrons. The approaches we used to reduce cost and the resulting design compromises will be discussed.

Download or read book The SNS Linac High Power RF System Design Status and Results written by and published by . This book was released on 2003 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Spallation Neutron Source being built at the Oak Ridge National Lab in Tennessee requires a 1 GeV proton linac. Los Alamos has responsibility for the RF systems for the entire linac. The linac requires 3 distinct types of RF systems: 2.5-MW peak, 402.5 MHz, RF systems for the RFQ and DTL (7 systems total); 5-MW peak, 805 MHz systems for the CCL and the two energy corrector cavities (6 systems total); and 550-kW peak, 805 MHz systems for the superconducting sections (8 1 systems total). The design of the SNS Linac RF system was presented at the 2001 Particle Accelerator Conference in Chicago. Vendors have been selected for the klystrons (3 different vendors), circulators (I vendor), transmitter (1 vendor), and high power RF loads (3 different vendors). This paper presents the results and status of vendor procurements, test results of the major components of the Linac RF system and our installation progress.

Download or read book The RF System for the National Spallation Neutron Source Linac written by and published by . This book was released on 1997 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: The National Spallation Neutron Source (NSNS) system has been proposed to dramatically improve the neutron capabilities for science applications in the US. The NSNS is a fast pulse neutron source that would consist of a 1000 MeV H-linac, an accumulator ring, a neutron target, and an experimental area. Although the NSNS is to be built at Oak Ridge, the design responsibility is delegated to five US national laboratories, and the Los Alamos National Laboratory is responsible for the linac portion of this machine, from the output of the radio frequency quadrupole (RFQ) accelerator, to the entrance to the accumulator ring. In the baseline design, a total of 59 klystrons are used to provide the RF power for a 1-MW average power beam in the accumulator ring, and a 1.04 ms pulse length, 6.24% duty factor beam in the linac. The frequencies chosen are 402.5 MHz for the RFQ and drift tube linac (DTL) portions of the machine, and 805 MHz for the coupled-cavity DTL (CCDTL) and coupled cavity (CCL) portions of the linac. The baseline 805 MHz klystron is capable of 2.5 MW peak power into a flat load, and it contains a modulating anode. The backup 805 MHz klystron is cathode pulsed, and has a 5 MW peak output power. The modulators for these two klystrons are vastly different. The challenges and compromises for the two klystrons and their associated modulators and RF systems are discussed. The baseline design RF system is presented in detail.

Download or read book Spallation Neutron Source High power Rf Transmitter Design for High Availablility Ease of Installation and Cost Containment written by and published by . This book was released on 2003 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: The availability goals and installation schedule for the Spallation Neutron Source (SNS) have driven the availability and installation of the SNS linac's high-power RF systems. This paper discusses how the high-power RF systems' availability and installation goals have been addressed in the RF transmitter design and procurement. Design features that allow R1; component failures to be quickly diagnosed and repaired are also presented. Special attention has been given lo interlocks, PLC fault logging and real-time interfaces to thc accelerator's Experimental Physics and Industrial Control System (EPICS) archive system. The availability and cost motivations for the use of different RF transmitter designs in the normalconducting and super-conducting sections of the linac are reviewed. Factory iicceptance tests used to insure fully functional equipment and thereby reduce the time spent on installation and cotnmissioning of the RF transmitters are discussed. Transmitter installation experience and klystron conditioning experience is used to show how these design features have helped and will continue to help the SNS linac to meet its availability and schedule goals.

Download or read book STATUS OF THE OAK RIDGE SPALLATION NEUTRON SOURCE SNS RF SYSTEMS written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The SNS has been delivering production neutrons for five years with first beam delivered to the neutron target at the end of April 2006. On September 18, 2009 SNS officially reached 1 megawatt of beam on target marking the achievement of a decades-old dream of providing a U.S. megawatt class pulsed spallation source. The SNS is now routinely delivering 1 megawatt of beam power to the neutron target at over 85 percent of the scheduled beam time. The present effort is aimed at increasing availability eventually to 95 percent and gradually increasing the intensity to the 1.4 megawatt design level. While the RF systems have performed well since initial installation some improvements have been implemented. This paper provides a review of the SNS RF Systems, an overview of the performance of the various components and a detailed review of RF related issues addressed over the past several years.

Download or read book Spallation Neutron Source written by and published by . This book was released on 1993 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: The rf system for the synchrotrons of the spallation neutron source is designed to accelerate 1.4 x 1014 protons/pulse to an energy of 3.6 GeV. Injection energy is 600 MeV. The synchrotron repetition frequency is 30 Hz, with a 50% duty factor. The choice of operating frequency is somewhat arbitrary. The authors propose a low frequency of 1.3 to 1.6 MHz, which is the second harmonic of the revolution frequency. The advantages of such a low frequency system are: (1) There will be two bunches in the machines and the time between bunches will be sufficiently long to allow for the rise time of the extraction kicker. No missing bunches will be necessary, which simplifies injection, and transient beam loading problems are avoided. (2) With only two bunches there are no unstable coupled-bunch modes of longitudinal instability. (3) In multi-gap low frequency cavities the transient time factor is essentially unity because the rf wavelength is much longer than the cavity dimensions. (4) Cavities in this low frequency range are basically lumped-element type structures, where the sources of the inductance and capacitance are clearly identified. This allows effective control of higher order mode impedances in such cavities. (5) Ferrite-loaded low-frequency cavities are necessarily low impedance structures; ferrites are lossy. This low impedance makes it possible to achieve system stability without large amounts of feedback in a heavily beam loaded system. (6) BNL has a good deal of experience in building rf systems in this range of frequency, voltage, and power level. This report outlines the essential parameters of a practical rf system for the synchrotrons of the Spallation Neutron Source. The design uses materials, ferrites and vacuum tubes, that are commercially available and with which the laboratory has recent experience.

Download or read book Modeling and Design of a Low level RF Control System for the Accumulator Ring at Spallation Neutron Source written by Michael G. Trout and published by . This book was released on 2017 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since its commissioning in 2006, Spallation Neutron Source (SNS) at Oak Ridge National Laboratory has greatly contributed to the field of neutron science, but some critical systems are reaching end-of-life. This obsolescence must be addressed for the accelerator to continue providing world-class research capabilities. One such system needing redesign is the low-level RF (LLRF) control system for the proton accumulator ring. While this system has performed acceptably for over a decade, it is sparsely documented and robust operational models are unavailable. To ensure the new design meets or exceeds current performance metrics, we analyzed the existing LLRF control system and designed a system-accurate controller model. This model included a state-space representation of the RF accelerator cavity dynamics. Both the controller and cavity models are combined to provide complete, functional simulation capabilities for the SNS accumulator ring LLRF control system. We then realized the modeled controller in an FPGA using VHDL cores which were subsequently used to successfully regulate the accumulator ring. The designed controller was functional at repetition rates up to 160 Hz while system specifications only require 60 Hz operation. The designed controller achieved 1 MW beam-on-target operation at 60 Hz repetition rate and a fundamental frequency of approximately 1 MHz.

Download or read book Construction and Operation of the Spallation Neutron Source TN NY IL NM written by and published by . This book was released on 1999 with total page 726 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book DESIGN OF THE SNS NORMAL CONDUCTING LINAC RF CONTROL SYSTEM written by and published by . This book was released on 2000 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Spallation Neutron Source (SNS) is in the process of being, designed for operation in 2004. The SNS is a 1 GeV machine consisting of both a normal-conducting and super-conducting linac as well as a ring and target area The linac front end is a 402.5 MHz RFQ being developed by Lawrence Berkeley Lab. The DTL, being developed at Los Alamos National Laboratory, is also a copper structure operating at 402.5 MHz, with an 805 MHz CCL structure downstream of it. The expected output energy of the DTL is 87 MeV and that of the CCL is 185 MeV. The RF control system under development for the linac is based on the Low Energy Demonstration Accelerator's (LEDA) control system with some new features. This paper will discuss the new design approach and its benefits. Block diagrams and circuit specifics will be addressed. The normal conducting RF control system will be described in detail with reference to the super-conducting control system when appropriate.

Download or read book EXCESS RF POWER REQUIRED FOR RF CONTROL OF THE SPALLATION NEUTRON SOURCE SNS LINAC A PULSED HIGH INTENSITY SUPERCONDUCTING PROTON ACCELERATOR written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A high-intensity proton linac, such as that being planned for the SNS, requires accurate RF control of cavity fields for the entire pulse in order to avoid beam spill. The current design requirement for the SNS is RF field stability within "0.5% and "0.5{sup o} [1]. This RF control capability is achieved by the control electronics using the excess RF power to correct disturbances. To minimize the initial capital costs, the RF system is designed with 'just enough' RF power. All the usual disturbances exist, such as beam noise, klystron/HVPS noise, coupler imperfections, transport losses, turn-on and turn-off transients, etc. As a superconducting linac, there are added disturbances of large magnitude, including Lorentz detuning and microphonics. The effects of these disturbances and the power required to correct them are estimated, and the result shows that the highest power systems in the SNS have just enough margin, with little or no excess margin.

Download or read book Energy Research Abstracts written by and published by . This book was released on 1995 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book LORENTZ FORCE DETUNING ANALYSIS OF THE SPALLATION NEUTRON SOURCE ACCELERATING CAVITIES written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Spallation Neutron Source (SNS) project incorporates a superconducting radio-frequency (SRF) accelerator for the final section of the pulsed mode linac. Cavities with geometrical [beta] values of [beta]=0.61 and [beta]=0.81 are utilized in the SRF section, and are constructed out of thin-walled niobium with stiffener rings welded between the cells near the iris. The welded titanium helium vessel and tuner assembly restrains the cavity beam tubes. Cavities with [beta] values less than one have relatively steep and flat side-walls making the cavities susceptible to Lorentz force detuning. In addition, the pulsed RF induces cyclic Lorentz pressures that mechanically excite the cavities, producing a dynamic Lorentz force detuning different from a continuous RF system. The amplitude of the dynamic detuning for a given cavity design is a function of the mechanical damping, stiffness of the tuner/helium vessel assembly, RF pulse profile, and the RF pulse rate. This paper presents analysis and testing results to date, and indicates areas where more investigation is required.

Download or read book Development of RF Accelerating Structures in the Front end System of Light Ion Particle Accelerators written by Ki Ryung Shin and published by . This book was released on 2014 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL) is an RF linear accelerator-based neutron source which utilizes various RF cavity resonators to interact with a traveling particle beam to transfer energy to the beam. The RF cavity resonator generates a strong electromagnetic modal field specifically shaped at an operating frequency to provide good energy efficiency. Having a reliable cavity RF field is therefore, important to sustain performance and stable operation of the accelerator system. Although the SNS system is already built and in use, some parts still need to be improved to achieve better performance and higher operational reliability. Our study can provide potential improvements in existing accelerators as well as future ones. For example, the performance and reliability of the radio frequency quadrupole (RFQ) and the rebuncher cavities in the low beam energy front-end section of the SNS accelerators, have been improved by applying our newly proposed design ideas. In this dissertation, we propose four development directions for RFQ and rebuncher cavity to enhance its performance and field stabilization. These include: 1) a practical design method to determine RFQ fabrication tolerance based on extensive 3D simulations to help reduce RFQ fabrication errors. 2) alternative RFQ designs to improve RFQ mode separation with lower fabrication, tuning costs and structural reliability. 3) a multi-section RFQ with new RF coupling scheme which is validated with scaled prototyping. This design eliminates spurious electromagnetic modes and can decrease manufacturing and tuning costs of long coupled RFQs. 4) a double gap rebuncher cavity design instead of a single cavity for decreased gap voltage and peak electric field. This design modification can reduce X-ray radiation intensity which can address safety problems in the current accelerator front-end area. A summary of our proposed solutions and contributions are presented in this dissertation paper.

Download or read book RF System Developments for CW and written by and published by . This book was released on 1998 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: High Power Proton Linacs are under development or proposed for development at Los Alamos and elsewhere. By current standards these linacs all require very large amounts of RF power. The Accelerator for Production of Tritium (APT) is a CW accelerator with an output current and energy of 100 mA and 1,700 MeV, respectively. The Spallation Neutron Source (SNS), in its ultimate configuration, is a pulsed accelerator with an average output power of 4 MW of beam. Other accelerators such as those that address transmutation and upgrades to LANSCE have similar requirements. For these high average power applications, the RF systems represent approximately half of the total cost of the linac and are thus key elements in the design and configuration of the accelerator. Los Alamos is fortunate to be actively working on both APT and SNS. For these programs the author is pursuing a number of component developments which are aimed at one or more of the key issues for large RF systems: technical performance, capital cost, reliability, and operating efficiency. This paper briefly describes some of the linac applications and then provides updates on the key RF developments being pursued.

Download or read book The Savannah River Accelerator Project And Complementary Spallation Neutron Sources written by Frank T Avignone Iii and published by World Scientific. This book was released on 1998-02-24 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: This proceedings volume is a collection of papers dealing with the applications of spallation neutron sources to pure science, applied science and defense programs. The topics, ranging from accelerator technology to applications in materials science and neutrino physics, are covered by experts in their respective fields.

Download or read book Cyclotrons And Their Applications Proceedings Of The 14th International Conference written by John Christopher Cornell and published by World Scientific. This book was released on 1996-06-12 with total page 894 pages. Available in PDF, EPUB and Kindle. Book excerpt: These conference proceedings will be of interest to all accelerator scientists and engineers, as well as those concerned with the application of cyclotrons in various fields. The conference covers the latest developments in the science, technology and use of cyclotrons, and includes more than 25 invited talks by specialists in their respective fields. Contributions include papers on newly operating cyclotrons and facilities under construction, compact cyclotrons, cooler rings and post-accelerators, ion sources, beam dynamics, beam diagnostics, cyclotron components, systems and technologies, as well as medical applications — including radiotherapy and radioisotope production — non-medical applications, radioactive beam facilities and new projects and proposals.

Download or read book Cyclotrons and Their Applications written by John Christopher Cornell and published by World Scientific. This book was released on 1996 with total page 894 pages. Available in PDF, EPUB and Kindle. Book excerpt: