The RF system for the 70 MeV linac injector

International Nuclear Information System (INIS)

Planner, C.W.

1975-12-01

The Radio Frequency System for the 70 MeV Linac Injector for Nimrod is required to power the four Accelerating Cavities and the Buncher and Debuncher Cavities. The frequency of operation is 202.5 MHz and is determined by the use of existing equipment from the redundant 50 MeV Proton Linac for the second and third accelerating cavities and the buncher and de-buncher cavities. The subject is discussed under the following headings: low power drive chain; RF feed lines; cavity field level stabilisation. Circuit diagrams are presented. (U.K.)

RF acceleration of intense laser generated proton bunches

Energy Technology Data Exchange (ETDEWEB)

Almomani, Ali

2012-07-13

With respect to laser-accelerated beams, the high current capability of the CH-DTL cavity has been investigated. Beam simulations have demonstrated that 10{sup 10} protons per bunch can be accelerated successfully and loss free along the structure. It was shown that, the maximum number of protons per bunch that can be accelerated in the first cavity by exploiting about 1% of the stored field energy is 2.02 x 10{sup 11} protons. One further aspect is the total number of protons arriving at the linac entrance. One main aspect of an rf postacceleration experiment is the rf operation stability under these beam load conditions. Detailed simulations from the target along the solenoid and down to the linac entrance were presented, applying adapted software. Special care was taken on the time steps, especially close to the target, and on the collective phenomena between electron and proton distributions. The effect of comoving electrons on the beam dynamics has been investigated in detail. A CH-linac with high space charge limit and large transverse and longitudinal acceptance was designed to accept a maximum fraction of the laser generated proton bursts. Due to well-known transformations of the injected beam emittances along the CH-cavity, it is aimed to derive parameters of the laser generated beam by measuring the beam properties behind of the CH-cavity. With respect to the linac development it is intended to realize the first cavity of the proposed CH-DTL and to demonstrate the acceleration of a laser generated proton bunch with the LIGHT project. The first cavity consists of 7 gaps within a total length of about 668 mm. It is operated at 325 MHz and has an effective accelerating field gradient of about 12.6 MV/m. The study on the surface electric field for this cavity shows, that maximum surface fields of about 94 MV/m and 88 MV/m on the third and sixth drift tubes are reachable, respectively.

Report of the design study on the proton linac of the Japanese Hadron Project, 2

International Nuclear Information System (INIS)

1990-06-01

The design study on the proton linac of the Japanese Hadron Project began in May 1987, in the collaboration of Institute for Nuclear Study, University of Tokyo and National Laboratory for High Energy Physics. This is the second report of the design study on the 1-GeV proton linac, which includes the developments of the ion source, RFQ, DTL, CCL and RF sources. (author)

Physics design of APT linac with normal conducting rf cavities

International Nuclear Information System (INIS)

Nath, S.; Billen, J.H.; Stovall, J.E.; Takeda, Harunori; Young, L.M.

1996-01-01

The accelerator based production of tritium calls for a high-power, cw proton linac. Previous designs for such a linac use a radiofrequency quadrupole (RFQ), followed by a drift-tube linac (DTL) to an intermediate energy and a coupled-cavity linc (CCL) to the final energy. The Los Alamos design uses a high-energy (6.7 MeV) RFQ followed by the newly developed coupled-cavity drift-tube linac (CCDTL) and a CCL. This design accommodates external electromagnetic quadrupole lenses which provide a strong uniform focusing lattice from the end of the RFQ to the end of the CCL. The cell lengths in linacs of traditional design are typically graded as a function of particle velocity. By making groups of cells symmetric in both the CCDTL and CCL, the cavity design as well as mechanical design and fabrication is simplified without compromising the performance. At higher energies, there are some advantages of using superconducting rf cavities. Currently, such schemes are under vigorous study. This paper describes the linac design based on normal conducting cavities and presents simulation results

Multiplacting analysis on 650 MHz, BETA 0.61 superconducting RF LINAC cavity

International Nuclear Information System (INIS)

Seth, Sudeshna; Som, Sumit; Mandal, Aditya; Ghosh, Surajit; Saha, S.

2013-01-01

Design, analysis and development of high-β multi-cell elliptical shape Superconducting RF linac cavity has been taken up by VECC, Kolkata as a part of IIFC collaboration. The project aims to provide the-art technology achieving very high electric field gradient in superconducting linac cavity, which can be used in high energy high current proton linear accelerator to be built for ADSS/SNS programme in India and in Project-X at Fermilab, USA. The performance of this type of superconducting RF structure can be greatly affected due to multipacting when we feed power to the cavity. Multipacting is a phenomenon of resonant electron multiplication in which a large number of electrons build up an electron Avalanche which absorbs RF Energy leading to remarkable power losses and heating of the walls, making it impossible to raise the electric field by increasing the RF Power. Multipacting analysis has been carried out for 650 MHz, β=0.61, superconducting elliptical cavity using 2D code MultiPac 2.1 and 3 D code CST particle studio and the result is presented in this paper. (author)

10 MeV RF electron linac for industrial applications

International Nuclear Information System (INIS)

2017-01-01

Electron linacs have found numerous applications in the field of radiation processing on an industrial scale. High power RF electron linacs are commonly used for food irradiation, medical sterilization, cross-linking of polymers, etc. For this purpose, the 10 MeV RF linac has been indigenously designed, developed, commissioned and is being used regularly at 3 kW beam power. This paper gives a brief description of the linac and its utilization for various applications. Safety considerations and regulatory aspects of the linac are also discussed

RF linacs for FELs

International Nuclear Information System (INIS)

Schwettman, H.A.

1992-01-01

There are twenty rf linac-driven Free Electron Lasers (FELs) existing or under construction throughout the world and proposals for several more. A number of these FELs have recently been established as facilities to produce coherent optical beams for materials and biomedical research. Both short pulse low duty factor and long pulse high duty factor linac-driven FELs will be discussed. Accelerator issues that influence the performance of an FEL as a scientific instrument will be indicated. (Author) 6 refs., 6 figs., 2 tabs

High duty factor plasma generator for CERN's Superconducting Proton Linac.

Science.gov (United States)

Lettry, J; Kronberger, M; Scrivens, R; Chaudet, E; Faircloth, D; Favre, G; Geisser, J-M; Küchler, D; Mathot, S; Midttun, O; Paoluzzi, M; Schmitzer, C; Steyaert, D

2010-02-01

CERN's Linac4 is a 160 MeV linear accelerator currently under construction. It will inject negatively charged hydrogen ions into CERN's PS-Booster. Its ion source is a noncesiated rf driven H(-) volume source directly inspired from the one of DESY and is aimed to deliver pulses of 80 mA of H(-) during 0.4 ms at a 2 Hz repetition rate. The Superconducting Proton Linac (SPL) project is part of the luminosity upgrade of the Large Hadron Collider. It consists of an extension of Linac4 up to 5 GeV and is foreseen to deliver protons to a future 50 GeV synchrotron (PS2). For the SPL high power option (HP-SPL), the ion source would deliver pulses of 80 mA of H(-) during 1.2 ms and operate at a 50 Hz repetition rate. This significant upgrade motivates the design of the new water cooled plasma generator presented in this paper. Its engineering is based on the results of a finite element thermal study of the Linac4 H(-) plasma generator that identified critical components and thermal barriers. A cooling system is proposed which achieves the required heat dissipation and maintains the original functionality. Materials with higher thermal conductivity are selected and, wherever possible, thermal barriers resulting from low pressure contacts are removed by brazing metals on insulators. The AlN plasma chamber cooling circuit is inspired from the approach chosen for the cesiated high duty factor rf H(-) source operating at SNS.

Superconducting RF for energy-recovery linacs

International Nuclear Information System (INIS)

Liepe, M.; Knobloch, J.

2006-01-01

Since superconducting RF for particle accelerators made its first appearance in the 1970s, it has found highly successful application in a variety of machines. Recent progress in this technology has made so-called Energy-Recovery Linacs (ERLs)-originally proposed in 1965-feasible, and interest in this type of machine has increased enormously. A superconducting linac is the driving heart of ERLs, and emittance preservation and cost efficiency is of utmost importance. The resulting challenges for the superconducting cavity technology and RF field control are manifold. In March 2005 the first international workshop on ERLs was held at Newport News, VA, to explore the potential of ERLs and to discuss machine-physics and technology challenges and their solutions. This paper reviews the state-of-the-art in superconducting RF and RF control for ERLs, and summarizes the discussions of the SRF working group on this technology during the ERL2005 workshop

The RF system for FELI linac

International Nuclear Information System (INIS)

Morii, Y.; Abe, S.; Keishi, T.; Tomimasu, T.

1995-01-01

FELI (Free Electron Laser Research Institute, Inc.) is constructing a Free Electron Laser facility covering from 20μm (infra red region) to 0.35μm (ultra violet region), using as S-band linac. The linac consists of a thermoionic 0.5ns-pulse triggered gun, a 714-MHz SHB (subharmonic buncher), a 2856-MHz standing wave type buncher, and seven ETL (Electro-technical Laboratory) type accelerating sections. An RF system of the linac for FELs is required of long pulse duration and high stability. Two S-band klystrons (TOSHIBA E3729) are operated in three pulse operation modes (pulse width and peak RF power): 24μs-24MW, 12.5μs-34MW, 0.5μs-70MW. Each klystron modulator has a PFN consisting of 4 parallel networks of 24 capacitors and 24 variable inductors, and it has a line switch of an optical thyristor stack. An S-band klystron and its modulator were combined to test their performance at the works of NISSIN ELECTRIC Co. in December 1993. These equipments were installed at FELI in January 1994. The design and experimental results of the RF system are summarized in this paper. (author)

Status of RF superconductivity at Argonne

International Nuclear Information System (INIS)

Shepard, K.W.

1990-01-01

Development of a superconducting slow-wave structures began at Argonne National Laboratory (ANL) in 1971, and led to the first superconducting heavy-ion linac (ATLAS - the Argonne Tandem-Linac Accelerator System). The Physics Division at ANL has continued to develop superconducting RF technology for accelerating heavy-ions, with the result that the linac has been in an almost continuous process of upgrade and expansion. In 1987, the Engineering Physics Division at ANL began developing of superconducting RF components for the acceleration of high-brightness proton and deuterium beams. The two divisions collaborate in work on several applications of RF superconductivity, and also in work to develop the technology generally. The present report briefly describes major features of the superconducting heavy-ion linac (very-low-velocity superconducting linac, positive ion injector), proton accelerating structures (superconducting resonant cavities for acceleration of high-current proton and deuteron beams, RF properties of oxide superconductors), and future work. Both divisions expect to continue a variety of studies, frequently in collaboration, to advance the basic technology of RF superconductivity. (N.K.)

High duty factor Plasma Generator for CERN’s Superconducting Proton Linac

CERN Document Server

Lettry, J; Scrivens, R; Chaudet, E; Faircloth, D; Favre, G; Geisser, JM; Kuchler, D; Mathot, S; Midttun, O; Paoluzzi, M; Schmitzer, C; Steyaert, D

2010-01-01

CERN’s Linac4 is a 160 MeV linear accelerator currently under construction. It will inject negatively charged hydrogen ions into CERN’s PS-Booster. Its ion source is a non-cesiated RF driven H- volume source directly inspired from the one of DESY and is aimed to deliver pulses of 80 mA of H- during 0.4 ms at a 2 Hz repetition rate. The Superconducting Proton Linac (SPL) project is part of the luminosity upgrade of the LHC, it consists of an extension of Linac4 up to 5 GeV and is foreseen to deliver protons to a future 50 GeV Synchrotron (PS2). For the SPL high power option (HP-SPL), the ion source would deliver pulses of 80 mA of H- during 1.2 ms and operate at a 50 Hz repetition rate. This significant upgrade motivates the design of the new water cooled plasma generator presented in this paper. Its engineering is based on the results of a finite element thermal study of the Linac4 H- plasma generator that identified critical components and thermal barriers. A cooling system is proposed which achieves the...

Proton injection and RF capture in the national spallation neutron source

International Nuclear Information System (INIS)

Luccio, A.U.; Beebe-Wang, J.; Maletic, D.

1997-01-01

The accelerator system for the 1 to 5 MW National Spallation Neutron Source (NSNS) consists of a linac followed by a 1 GeV proton accumulator ring. Since the ring is a very high current machine, the injection and rf capture of the protons is deeply affected by transverse and longitudinal space charge effects. Results of numerical simulation of the process are presented together with considerations on methods and results of space charge treatment in high intensity proton storage rings

On scaling and optimization of high-intensity, low-beam-loss RF linacs for neutron source drivers

International Nuclear Information System (INIS)

Jameson, R.A.

1992-01-01

RF linacs providing cw proton beams of 30--250 mA at 800--1600 MeV, and cw deuteron beams of 100--250 mA at 35--40 MeV, are needed as drivers for factory neutron sources applied to radioactive waste transmutation, advanced energy production, materials testing facilities, and spallation neutron sources. The maintenance goals require very low beam loss along the linac. Optimization of such systems is complex; status of beam dynamics aspects presently being investigated is outlined

A self-adaptive feedforward rf control system for linacs

International Nuclear Information System (INIS)

Zhang Renshan; Ben-Zvi, I.; Xie Jialin

1993-01-01

The design and performance of a self-adaptive feedforward rf control system are reported. The system was built for the linac of the Accelerator Test Facility (ATF) at Brookhaven National Laboratory. Variables of time along the linac macropulse, such as field or phase are discretized and represented as vectors. Upon turn-on or after a large change in the operating-point, the control system acquires the response of the system to test signal vectors and generates a linearized system response matrix. During operation an error vector is generated by comparing the linac variable vectors and a target vector. The error vector is multiplied by the inverse of the system's matrix to generate a correction vector is added to an operating point vector. This control system can be used to control a klystron to produce flat rf amplitude and phase pulses, to control a rf cavity to reduce the rf field fluctuation, and to compensate the energy spread among bunches in a rf linac. Beam loading effects can be corrected and a programmed ramp can be produced. The performance of the control system has been evaluated on the control of a klystron's output as well as an rf cavity. Both amplitude and phase have been regulated simultaneously. In initial tests, the rf output from a klystron has been regulated to an amplitude fluctuation of less than ±0.3% and phase variation of less than ±0.6deg. The rf field of the ATF's photo-cathode microwave gun cavity has been regulated to ±5% in amplitude and simultaneously to ±1deg in phase. Regulating just the rf field amplitude in the rf gun cavity, we have achieved amplitude fluctuation of less than ±2%. (orig.)

Study on design of proton linacs

International Nuclear Information System (INIS)

Yu Qingchang

2000-01-01

Two important directions in the development of proton linacs are high-current proton linacs (mainly applied in nuclear power field) and compact proton linacs (for proton therapy). There are some common characteristics in them: (1) Employment of the novel accelerating structures, which are combination and evolution of the conventional ones; (2) Accelerating beam with small emittance; (3) Requirement for high reliability. The construction of the former is, however, much more difficult because it still needs low beam lose rate and as high power transformation efficiency as possible. Some important problems in the design of these accelerators are discussed and some schemes designed are presented

Simplified RF power system for Wideroe-type linacs

International Nuclear Information System (INIS)

Fugitt, J.; Howard, D.; Crosby, F.; Johnson, R.; Nolan, M.; Yuen, G.

1981-03-01

The RF system for the SuperHILAC injector linac was designed and constructed for minimum system complexity, wide dynamic range, and ease of maintenance. The final amplifier is close coupled to the linac and operates in an efficient semilinear mode, eliminating troublesome transmission lines, modulators, and high level regulators. The system has been operated at over 250 kW, 23 MHz with good regulation. The low level RF electronics are contained in a single chassis adjacent to the RF control computer, which monitors all important operating parameters. A unique 360 0 phase and amplitude modular is used for precise control and regulation of the accelerating voltage

RF control at transient beamloading for high-duty-factor linacs

Energy Technology Data Exchange (ETDEWEB)

Chernogubovsky, M.A.; Sugimoto, Masayoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1998-08-01

An effective RF control with the transient beamloading is the major issue in the operation of the high-duty-factor linacs to suppress the undesirable beam loss. The RF control method is considered to obtain the control principle and the state equation, under the analysis of electrodynamical properties of the excitation in the resonator of the linac due to the transient beamloading. The concept of the directional selective coupling is applied for the RF system to define the main characteristics and to optimize the RF control parameters. (author)

ENERGY CORRECTION FOR HIGH POWER PROTON/H MINUS LINAC INJECTORS.

Energy Technology Data Exchange (ETDEWEB)

RAPARIA, D.; LEE, Y.Y.; WEI, J.

2005-05-16

High-energy proton/H minus energy (> GeV) linac injector suffer from energy jitter due to RF amplitude and phase stability. Especially in high power injectors this energy jitter result beam losses more than 1 W/m that require for hand on maintenance. Depending upon the requirements for next accelerator in the chain, this energy jitter may or may not require to be corrected. This paper will discuss the sources of this energy jitter, correction schemes with specific examples.

Development of a large proton accelerator for innovative researches; development of high power RF source

Energy Technology Data Exchange (ETDEWEB)

Chung, K. H.; Lee, K. O.; Shin, H. M.; Chung, I. Y. [KAPRA, Seoul (Korea); Kim, D. I. [Inha University, Incheon (Korea); Noh, S. J. [Dankook University, Seoul (Korea); Ko, S. K. [Ulsan University, Ulsan (Korea); Lee, H. J. [Cheju National University, Cheju (Korea); Choi, W. H. [Korea Advanced Institute of Science and Technology, Taejeon (Korea)

2002-05-01

This study was performed with objective to design and develop the KOMAC proton accelerator RF system. For the development of the high power RF source for CCDTL(coupled cavity drift tube linac), the medium power RF system using the UHF klystron for broadcasting was integrated and with this RF system we obtained the basic design data, operation experience and code-validity test data. Based on the medium power RF system experimental data, the high power RF system for CCDTL was designed and its performed was analyzed. 16 refs., 64 figs., 27 tabs. (Author)

Beam tests on a proton linac booster for hadron therapy

CERN Document Server

De Martinis, C; Berra, P; Birattari, C; Calabretta, L; Crandall, K; Giove, D; Masullo, M R; Mauri, M; Rosso, E; Rovelli, A; Serafini, L; Szeless, Balázs; Toet, D Z; Vaccaro, Vittorio G; Weiss, M; Zennaro, R

2002-01-01

LIBO is a 3 GHz modular side-coupled proton linac booster designed to deliver beam energies up to 200 MeV, as required for the therapy of deep seated tumours. The injected beam of 50 to 70 MeV is produced by a cyclotron like those in several hospitals and research institutes. A full-scale prototype of the first module with an input/output energy of 62/74 MeV, respectively, was designed and built in 1999 and 2000. Full power RF tests were carried out successfully at CERN using a test facility at LIL at the end of the year 2000. In order to prove the feasibility of the acceleration process, an experimental setup with this module was installed at the INFN Laboratorio Nazionale del Sud (LNS) in Catania during 2001. The superconducting cyclotron provided the 62 MeV test beam. A compact solid-state RF modulator with a 4 MW klystron, made available by IBA-Scanditronix, was put into operation to power the linac. In this paper the main features of the accelerator are reviewed and the experimental results obtained duri...

Emittance growth in rf linacs

International Nuclear Information System (INIS)

Jameson, R.A.

1979-01-01

As the space-charge limit is approached, the current that can be accelerated in an rf linac and the output emittance that can be expected are discussed. The role of the envelope equations to estimate limits is outlined. The results of numerical experiments to explore general properties of emittance growth are given

6 MeV RF Linac for cargo scanning and industrial radiography

International Nuclear Information System (INIS)

2017-01-01

RF Linac-based X-ray sources are very widely used for cargo-scanning and industrial X-ray radiography applications. A 6 MeV on-axis coupled-cavity S-band RF linac has been designed, developed and tested successfully at Electron Beam Centre, Navi Mumbai. This facility falls under the purview of BARC Safety Council, which has conducted safety reviews and awarded regulatory clearances for the operation of the linac system. This paper outlines the salient features of the 6 MeV linac, its safety aspects and test results. A brief history of regulatory aspects is also presented

Low power rf system for the ALS Linac

International Nuclear Information System (INIS)

Lo, C.C.; Taylor, B.; Lancaster, H.

1991-05-01

The Linear Accelerator (Linac) in the Advanced Light Source (ALS) is designed to provide either single or multiple bunchers of 50 MeV electrons for the booster synchrotron. Three cavities are used in the Linac for electron bunching. The two subharmonic bunching cavities operate at 124.914 MHz and 499.654 MHz respectively. The S Band buncher operates at 2.997924 GHz. The low level RF system includes a master signal source, RF burst generators, signal phase control, timing trigger generators and a water temperature control system. The design and performance of the system will be described. 7 refs., 3 figs

Overview and status of RF systems for the SSC Linac

International Nuclear Information System (INIS)

Mynk, J.; Grippe, J.; Cutler, R.I.; Rodriguez, R.

1993-05-01

The Superconducting Super Collider (SSC) Linear Accelerator (Linac) produces a 600-MeV, 35-μs, H-beam at a 10-Hz repetition rate. The beam is accelerated by a series of RF cavities. These consist of a Radio Frequency Quadrupole (RFQ), two bunchers, and four Drift Tube Linac (DTL) tanks at 427.617 MHz, and two bunchers, nine side-coupled Linac modules, and an energy compressor at 1282.851 MHz. The RFQ amplifier and the low-frequency buncher cavity amplifiers use gridded tubes, while the other cavities use klystron amplifier systems. The RF control system consists of a reference line and cavity feedback and feedforward loops for each amplifier. The RF amplifier system for each of these accelerator cavities is described, and the current status of each system is presented

Feedback system of the RF phase in KEK-ATF linac

Energy Technology Data Exchange (ETDEWEB)

Okugi, T.; Hayano, H.; Kuriki, M.; Naito, T. [Accelerator Laboratory, High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan)

2000-07-01

KEK-ATF linac is built in the Assembly Hall for TRISTAN project in 1991. The thermal condition of the hall is not good enough for a stable linac operation, because the temperature of the klystron gallery is drifted by 1degC within one day. RF phase is also drifted by 3-5deg of the S-band frequency in day and night. In order to control the RF phase, we installed RF phase detectors, which have S/H circuit in order to use for pulsed RF. By using the phase detector, an RF phase feedback system was tested. It was found that a stable klystron operation could be performed within the phase drift of {+-}0.5deg in a day. (author)

Assessment of the basic parameters of the CERN Superconducting Proton Linac

Directory of Open Access Journals (Sweden)

O. Brunner

2009-07-01

Full Text Available The construction of a 4 GeV superconducting proton linac (the SPL is now part of the long term plan of CERN, and the construction of Linac4, its low-energy front end, has begun. For mid-2012 the existing conceptual design of the SPL has to be refined and transformed into a project proposal. As a first step, basic parameters like rf frequency, accelerating gradient, and operating temperature of the superconducting cavities have been reassessed, taking into account the experience accumulated in the world during the recent years, especially for the Spallation Neutron Source (SNS in Oakridge and the International Linear Collider (ILC projects. The conclusions confirm the validity of the initial choices, namely, the rf frequency of 704.4 MHz and the cooling temperature of ≈2  K. However, the assumed gradients are estimated as optimistic: additional tests are necessary during the coming years to properly define the values to be used in the SPL design. This analysis is documented and its results are explained in this report.

Stabilization of the RF system at the SPring-8 linac

CERN Document Server

Asaka, T; Hori, T; Kobayashi, T; Mizuno, A; Sakaki, H; Suzuki, S; Taniuchi, T; Yanagida, K; Yokomizo, H; Yoshikawa, H

2002-01-01

Beam energy variation of the SPring-8 linac was 1% or more at the start of beam commissioning. Depending on fluctuation, beam transmission efficiency from the linac to the booster synchrotron was significantly affected, and beam intensity in the booster synchrotron changed 20-30%. This caused delay of optimization of the various parameters in the booster synchrotron. More problematic, the beam intensities stored in each RF (radio frequency) bucket of the storage ring at SPring-8 were all different from each other. The users utilizing synchrotron radiation requested that the beam intensity in each RF bucket be as uniform as possible. It was thus a pressing necessity to stabilize the beam energy in the linac. Investigation of the cause has clarified that the various apparatuses installed in the linac periodically changed depending on circumstances and utilities such as the air conditioner, cooling water and electric power. After various improvements, beam energy stability in the linac of <0.06% rms was attai...

Beam physics design strategy for a high-current rf linac

Energy Technology Data Exchange (ETDEWEB)

Reiser, M. [Univ. of Maryland, College Park, MD (United States)

1995-10-01

The high average beam power of an rf linac system for transmutation of nuclear waste puts very stringent requirements on beam quality and beam control. Fractional beam losses along the accelerator must be kept at extremely low levels to assure {open_quotes}hands-on{close_quotes} maintenance. Hence, halo formation and large-amplitude tails in the particle distribution due to beam mismatch and equipartitioning effects must be avoided. This implies that the beam should ideally be in near-perfect thermal equilibrium from injection to full energy - in contrast to existing rf linacs in which the transverse temperature, T {sub {perpendicular}}, is higher than the longitudinal temperature, T{sub {parallel}}. The physics and parameter scaling for such a system will be reviewed using the results of recent work on high-intensity bunched beams. A design strategy for a high-current rf linac with equilibrated beam will be proposed.

RF system considerations for large high-duty-factor linacs

International Nuclear Information System (INIS)

Lynch, M.T.; Ziomek, C.D.; Tallerico, P.J.; Regan, A.H.; Eaton, L.; Lawrence, G.

1994-01-01

RF systems are often a major cost item for linacs, but this is especially true for large high-duty-factor linacs (up to and including CW) such as the Accelerator for Production of Tritium (APT) or the Accelerator for Transmutation of nuclear Waste (ATW). In addition, the high energy and high average beam current of these machines (approximately 1 GeV, 100--200 mA) leads to a need for excellent control of the accelerating fields in order to minimize the possibility of beam loss in the accelerator and the resulting activation. This paper will address the key considerations and limitations in the design of the RF system. These considerations impact the design of both the high power RF components and the RF controls. As might be expected, the two concerns sometimes lead to conflicting design requirements. For example minimum RF operating costs lead to a desire for operation near saturation of the high power RF generators in order to maximize the operating efficiency. Optimal control of the RF fields leads to a desire for maximum overdrive capability in those same generators in order to respond quickly to disturbances of the accelerator fields

AN INTERNET RACK MONITOR-CONTROLLER FOR APS LINAC RF ELECTRONICS UPGRADE

Energy Technology Data Exchange (ETDEWEB)

Ma, Hengjie; Smith, Terry; Nassiri, Alireza; Sun, Yine; Doolittle, Lawrence; Ratti, Alex

2016-06-01

To support the research and development in APS LINAC area, the existing LINAC rf control performance needs to be much improved, and thus an upgrade of the legacy LINAC rf electronics becomes necessary. The proposed upgrade plan centers on the concept of using a modern, network-attached, rackmount digital electronics platform –Internet Rack Monitor-Controller (or IRMC) to achieve the goal of modernizing the rf electronics at a lower cost. The system model of the envisioned IRMC is basically a 3-tier stack with a high-performance DSP in the mid-layer to perform the core tasks of real-time rf data processing and controls. The Digital Front-End (DFE) attachment layer at bottom bridges the applicationspecific rf front-ends to the DSP. A network communication gateway, together with an embedded event receiver (EVR) in the top layer merges the Internet Rack MonitorController node into the networks of the accelerator controls infrastructure. Although the concept is very much in trend with today’s Internet-of-Things (IoT), this implementation has actually been used in the accelerators for over two decades.

Dynamic compensation of an rf cavity failure in a superconducting linac

Directory of Open Access Journals (Sweden)

Jean-Luc Biarrotte

2008-07-01

Full Text Available An accelerator driven system (ADS for transmutation of nuclear waste typically requires a 600 MeV–1 GeV accelerator delivering a proton flux of a few mA for demonstrators, and of a few tens of mA for large industrial systems. Such a machine belongs to the category of the high-power proton accelerators, with an additional requirement for exceptional “reliability”: because of the induced thermal stress to the subcritical core, the number of unwanted “beam trips” should not exceed a few per year, a specification that is several orders of magnitude above usual performance. In order to meet this extremely high reliability, the accelerator needs to implement, to the maximum possible extent, a fault-tolerance strategy that would allow beam operation in the presence of most of the envisaged faults that could occur in its beam line components, and in particular rf systems’ failures. This document describes the results of the simulations performed for the analysis of the fault-tolerance capability of the XT-ADS superconducting linac in the case of an rf cavity failure. A new simulation tool, mixing transient rf behavior of the accelerating cavities with full 6D description of the beam dynamics, has been developed for this purpose. Fast fault-recovery scenarios are proposed, and required research and development is identified.

Multi-cell disk-and-ring tapered structure for compact RF linacs

Energy Technology Data Exchange (ETDEWEB)

Smirnov, A.V.; Boucher, S.; Kutsaev, S. [RadiaBeam Systems LLC, 1713 Stewart Street, Santa Monica, CA 90404, US (United States); Hartzell, J. [RadiaBeam Technologies, LLC, 1717 Stewart Street, Santa Monica, CA 90404, US (United States); Savin, E. [RadiaBeam Technologies, LLC, 1717 Stewart Street, Santa Monica, CA 90404, US (United States); National Research Nuclear University “MEPhI”, Moscow 115409 (Russian Federation)

2016-09-11

A tubular disk-and-ring, tapered accelerating structure for small electron linacs and MicroLinacs is considered. It consists of metal and dielectric elements inserted into a metallic tube to eliminate multi-cell, multi-step brazing. The structure enables a wide range of phase velocities (including non-relativistic), a wide bandwidth allowing large number of cells (for standing wave mode) or short filling time (for traveling wave mode), combination of compensated and purely π-mode cells, alternative periodic focusing built-in to the RF structure (the disks), and combining of RF and vacuum windows. RF and accelerating performance of such a long structure having up to four dozens cells is analyzed. Some of beam dynamics, thermal, and vacuum aspects of the structure and MicroLinac performance are considered as well.

Multi-cell disk-and-ring tapered structure for compact RF linacs

International Nuclear Information System (INIS)

Smirnov, A.V.; Boucher, S.; Kutsaev, S.; Hartzell, J.; Savin, E.

2016-01-01

A tubular disk-and-ring, tapered accelerating structure for small electron linacs and MicroLinacs is considered. It consists of metal and dielectric elements inserted into a metallic tube to eliminate multi-cell, multi-step brazing. The structure enables a wide range of phase velocities (including non-relativistic), a wide bandwidth allowing large number of cells (for standing wave mode) or short filling time (for traveling wave mode), combination of compensated and purely π-mode cells, alternative periodic focusing built-in to the RF structure (the disks), and combining of RF and vacuum windows. RF and accelerating performance of such a long structure having up to four dozens cells is analyzed. Some of beam dynamics, thermal, and vacuum aspects of the structure and MicroLinac performance are considered as well.

Gain physics of rf-linac-driven xuv free-electron lasers

International Nuclear Information System (INIS)

Goldstein, J.C.; McVey, B.D.; Newnam, B.E.

1986-01-01

In an rf-linac-driven xuv free-electron laser oscillator, the gain depends on the details of the shape of the electron beam's phase-space distribution, particularly the distribution of electrons in the transverse (to the direction of propagation) position and velocity coordinates. This strong dependence occurs because the gain in this device is inhomogeneously broadened. Our previous theoretical studies have assumed that the transverse phase space distribution is a product of uncorrelated Gaussian functions. In the present work, we shall present the results of a theoretical study of the gain for non-Gaussian phase-space distributions. Such distributions arise either from a better representation of the electron beam from an rf-linac or from an emittance filter applied to the beam after the linac

Development of RF System Model for CERN Linac2 Tanks

CERN Document Server

Joshi, G; Vretenar, M; Kumar, G; Agarwal, V

2010-01-01

An RF system model has been created for the CERN Linac2 Tanks. RF systems in this linac have both single and double feed architectures. The main elements of these systems are: RF power amplifier, main resonator, feed-line and the amplitude and phase feedback loops. The model of the composite system is derived by suitably concatenating the models of these individual sub-systems. For computational efficiency the modeling has been carried out in the base band. The signals are expressed in in-phase - quadrature domain, where the response of the resonator is expressed using two linear differential equations, making it valid for large signal conditions. MATLAB/SIMULINK has been used for creating the model. The model has been found useful in predicting the system behaviour, especially during the transients. In the paper we present the details of the model, highlighting the methodology, which could be easily extended to multiple feed RF systems.

Beam dynamics studies of a 30 MeV RF linac for neutron production

Science.gov (United States)

Nayak, B.; Krishnagopal, S.; Acharya, S.

2018-02-01

Design of a 30 MeV, 10 Amp RF linac as neutron source has been carried out by means of ASTRA simulation code. Here we discuss details of design simulations for three different cases i.e Thermionic , DC and RF photocathode guns and compare them as injectors to a 30 MeV RF linac for n-ToF production. A detailed study on choice of input parameters of the beam from point of view of transmission efficiency and beam quality at the output have been described. We found that thermionic gun isn't suitable for this application. Both DC and RF photocathode gun can be used. RF photocathode gun would be of better performance.

Comparison of coaxial higher order mode couplers for the CERN Superconducting Proton Linac study

Directory of Open Access Journals (Sweden)

K. Papke

2017-06-01

Full Text Available Higher order modes (HOMs may affect beam stability and refrigeration requirements of superconducting proton linacs such as the Superconducting Proton Linac, which is studied at CERN. Under certain conditions beam-induced HOMs can accumulate sufficient energy to destabilize the beam or quench the superconducting cavities. In order to limit these effects, CERN considers the use of coaxial HOM couplers on the cutoff tubes of the 5-cell superconducting cavities. These couplers consist of resonant antennas shaped as loops or probes, which are designed to couple to potentially dangerous modes while sufficiently rejecting the fundamental mode. In this paper, the design process is presented and a comparison is made between various designs for the high-beta SPL cavities, which operate at 704.4 MHz. The rf and thermal behavior as well as mechanical aspects are discussed. In order to verify the designs, a rapid prototype for the favored coupler was fabricated and characterized on a low-power test-stand.

Comparison of coaxial higher order mode couplers for the CERN Superconducting Proton Linac study

CERN Document Server

AUTHOR|(CDS)2085329; Gerigk, Frank; Van Rienen, Ursula

2017-01-01

Higher order modes (HOMs) may affect beam stability and refrigeration requirements of superconducting proton linacs such as the Superconducting Proton Linac, which is studied at CERN. Under certain conditions beam-induced HOMs can accumulate sufficient energy to destabilize the beam or quench the superconducting cavities. In order to limit these effects, CERN considers the use of coaxial HOM couplers on the cutoff tubes of the 5-cell superconducting cavities. These couplers consist of resonant antennas shaped as loops or probes, which are designed to couple to potentially dangerous modes while sufficiently rejecting the fundamental mode. In this paper, the design process is presented and a comparison is made between various designs for the high-beta SPL cavities, which operate at 704.4 MHz. The rf and thermal behavior as well as mechanical aspects are discussed. In order to verify the designs, a rapid prototype for the favored coupler was fabricated and characterized on a low-power test-stand.

Assessment of Alternative RF Linac Structures for APT

Energy Technology Data Exchange (ETDEWEB)

None

1997-03-26

The APT program has been examining both normal and superconducting variants of the APT linac for the past two years. A decision on which of the two will be the selected technology will depend upon several considerations including the results of ongoing feasibility experiments, the performance and overall attractiveness of each of the design concepts, and an assessment of the system-level features of both alternatives. The primary objective of the Assessment of Alternative RF Linac Structures for APT study reported herein was to assess and compare, at the system-level, the performance, capital and life cycle costs, reliability/availability/maintainability (RAM) and manufacturing schedules of APT RF linear accelerators based upon both superconducting and normal conducting technologies. A secondary objective was to perform trade studies to explore opportunities for system optimization, technology substitution and alternative growth pathways and to identify sensitivities to design uncertainties.

Assessment of Alternative RF Linac Structures for APT

International Nuclear Information System (INIS)

None

1997-01-01

The APT program has been examining both normal and superconducting variants of the APT linac for the past two years. A decision on which of the two will be the selected technology will depend upon several considerations including the results of ongoing feasibility experiments, the performance and overall attractiveness of each of the design concepts, and an assessment of the system-level features of both alternatives. The primary objective of the Assessment of Alternative RF Linac Structures for APT study reported herein was to assess and compare, at the system-level, the performance, capital and life cycle costs, reliability/availability/maintainability (RAM) and manufacturing schedules of APT RF linear accelerators based upon both superconducting and normal conducting technologies. A secondary objective was to perform trade studies to explore opportunities for system optimization, technology substitution and alternative growth pathways and to identify sensitivities to design uncertainties

Experimental investigation of heating phenomena in linac mechanical interfaces due to RF field penetration

International Nuclear Information System (INIS)

Fazio, M.V.; Reid, D.W.; Potter, J.M.

1981-01-01

In a high duty-factor, high-current, drift-tube linear accelerator, a critical interface exists between the drift-tube stem and the tank wall. This interface must provide vacuum integrity and RF continuity, while simultaneously allowing alignment flexibility. Because of past difficulties with RF heating of vacuum bellows and RF joints encountered by others, a paucity of available information, and the high reliability requirement for the Fusion Materials Irradiation Test (FMIT) accelerator, a program was initiated to study the problem. Because RF heating is the common failure mode, an attempt was made to find a correlation between the drift-tube-stem/linac-tank interface geometry and RF field penetration from the tank into the interface region. Experiments were performed at 80 MHz on an RF structure designed to simulate the conditions to which a drift-tube stem and vacuum bellows are exposed in a drift-tube linac. Additional testing was performed on a 367-MHz model of the FMIT prototype drift-tube linac. Experimental results, and a method to predict excessive RF heating, is presented. An experimentally tested solution to the problem is discussed

Thermionic RF Gun and Linac Pre-Injector for SPEAR3

Energy Technology Data Exchange (ETDEWEB)

Park, S.

2003-08-11

Preparations are underway to upgrade the Spear2 to the third generation light source. Installation of all the subsystems will start in April 2003. Although the Spear3 RF system is entirely different from the present form, the pre-injector gun/linac and booster synchrotron will remain the same even after the upgrade. The thermionic rf gun reliability and stability are to be improved to inject 500 mA of stored current in shortest possible time. When a top-up mode is enforced, where the stored beam decay is replenished to maintain the constant current and thus constant light intensity, the Spear3 will take injection every few minutes. In that case the gun, linac, and booster must stay on at all times. In this report we will describe some improvements made on the gun and linac in the recent past, as well as their present performance and future upgrade to be made.

A photocathode rf gun design for a mm-wave linac-based FEL

Energy Technology Data Exchange (ETDEWEB)

Nassiri, A.; Berenc, T,; Foster, J.; Waldschmidt, G.; Zhou, J.

1995-07-01

In recent years, advances in the rf gun technology have made it possible to produce small beam emittances suitable for short period microundulators which take advantage of the low emittance beam to reduce the wavelength of FELs. At the Advanced Photon Source, we are studying the design of a compact 50-MeV superconducting mm-wave linac-based FEL for the production of short wavelengths ({approximately}300 nm) to carry out FEL demonstration experiments. The electron source considered for the linac is a 30- GHz, 3 1/2-cell {pi}-mode photocathode rf gun. For cold model rf measurements a 15-GHz prototype structure was fabricated. Here we report on the design, numerical modelling and the initial cold-model rf measurement results on the 15-GHz prototype structure.

A photocathode rf gun design for a mm-wave linac-based FEL

International Nuclear Information System (INIS)

Nassiri, A.; Berenc, T.; Foster, J.; Waldschmidt, G.; Zhou, J.

1995-01-01

In recent years, advances in the rf gun technology have made it possible to produce small beam emittances suitable for short period microundulators which take advantage of the low emittance beam to reduce the wavelength of FELs. At the Advanced Photon Source, we are studying the design of a compact 50-MeV superconducting mm-wave linac-based FEL for the production of short wavelengths (∼300 nm) to carry out FEL demonstration experiments. The electron source considered for the linac is a 30- GHz, 3 1/2-cell π-mode photocathode rf gun. For cold model rf measurements a 15-GHz prototype structure was fabricated. Here we report on the design, numerical modelling and the initial cold-model rf measurement results on the 15-GHz prototype structure

MEIC Proton Beam Formation with a Low Energy Linac

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yuhong [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

2015-09-01

The MEIC proton and ion beams are generated, accumulated, accelerated and cooled in a new green-field ion injector complex designed specifically to support its high luminosity goal. This injector consists of sources, a linac and a small booster ring. In this paper we explore feasibility of a short ion linac that injects low-energy protons and ions into the booster ring.

The FAIR proton linac

International Nuclear Information System (INIS)

Kester, O.

2015-01-01

FAIR - the Facility for Antiproton and Ion Research in Europe - constructed at GSI in Darmstadt comprises an international centre of heavy ion accelerators that will drive heavy ion and antimatter research. FAIR will provide worldwide unique accelerator and experimental facilities, allowing a large variety of fore-front research in physics and applied science. FAIR will deliver antiproton and ion beams of unprecedented intensities and qualities. The main part of the FAIR facility is a sophisticated accelerator system, which delivers beams to different experiments of the FAIR experimental collaborations - APPA, NuSTAR, CBM and PANDA - in parallel. Modern H-type cavities offer highest shunt impedances of resonant structures of heavy ion linacs at low beam energies < 20 MeV/u and enable the acceleration of intense proton and ion beams. One example is the interdigital H-type structure. The crossed-bar H-cavities extend these properties to high energies even beyond 100 MeV/u. Compared to conventional Alvarez cavities, these crossed-bar (CH) cavities feature much higher shunt impedance at low energies. The design of the proton linac is based on those cavities

All Digital IQ Servo-System for CERN Linacs

CERN Document Server

Rohlev, A; Garoby, R

2003-01-01

A new VME based system has been developed and built at CERN for the servo loops regulating the field in the linac accelerating structure. It makes use of high speed digital In-phase/Quadrature (IQ) detection, digital processing, and digital IQ modulation. The digital processing and IQ modulation is done in a single PLD. The system incorporates continually variable set points, iterative learning, feed forward as well as extensive diagnostics and other features well suited for digital implementations. Built on a single VME card, it will be first used in the energy ramping RF chain of the CERN Heavy Ion Linac (linac 3) and later for upgrading the present proton linac (linac 2). This system serves also as a prototype for the future Superconducting Proton Linac (SPL). The design principle and the experimental results are described.

Practical test of the LINAC4 RF power system

CERN Document Server

Schwerg, N

2011-01-01

The high RF power for the Linac4 accelerating structures will be generated by thirteen 1.3 MW klystrons, previously used for the CERN LEP accelerator, and six new klystrons of 2.8 MW all operating at a frequency of 352.2 MHz. The power distribution scheme features a folded magic tee feeding the power from one 2.8 MW klystron to two LEP circulators. We present first results from the Linac4 test place, validating the approach and the used components as well as reporting on the klystron re-tuning activities.

Digital low level RF control system for the DESY TTF VUV-FEL Linac

International Nuclear Information System (INIS)

Ayvazyan, V.; Choroba, S.; Matyushin, A.; Moeller, G.; Petrosyan, G.; Rehlich, K.; Simrock, S.N.; Vetrov, P.

2005-01-01

In the RF system for the Vacuum Ultraviolet Free Electron Laser (VUV-FEL) Linac each klystron supplies RF power to up to 32 cavities. The superconducting cavities are operated in pulsed mode and high accelerating gradients close to the performance limit. The RF control of the cavity fields to the level of 10 -4 for amplitude and 0.1 degree for phase however presents a significant technical challenge due to the narrow bandwidth of the cavities which results in high sensitivity to perturbations of the resonance frequency by mechanical vibrations (microphonics) and Lorenz force detuning. The VUV-FEL Linac RF control system employs a completely digital feedback system to provide flexibility in the control algorithms, precise calibration of the accelerating field vector-sum, and extensive diagnostics and exception handling capabilities. The RF control algorithm is implemented in DSP (Digital Signal Processor) firmware and DOOCS (Distributed Object Oriented Control System) servers. The RF control system design objectives are discussed. Hardware and software design of the DSP based RF control are presented. (orig.)

Digital low level RF control system for the DESY TTF VUV-FEL Linac

Energy Technology Data Exchange (ETDEWEB)

Ayvazyan, V.; Choroba, S.; Matyushin, A.; Moeller, G.; Petrosyan, G.; Rehlich, K.; Simrock, S.N.; Vetrov, P.

2005-07-01

In the RF system for the Vacuum Ultraviolet Free Electron Laser (VUV-FEL) Linac each klystron supplies RF power to up to 32 cavities. The superconducting cavities are operated in pulsed mode and high accelerating gradients close to the performance limit. The RF control of the cavity fields to the level of 10{sup -4} for amplitude and 0.1 degree for phase however presents a significant technical challenge due to the narrow bandwidth of the cavities which results in high sensitivity to perturbations of the resonance frequency by mechanical vibrations (microphonics) and Lorenz force detuning. The VUV-FEL Linac RF control system employs a completely digital feedback system to provide flexibility in the control algorithms, precise calibration of the accelerating field vector-sum, and extensive diagnostics and exception handling capabilities. The RF control algorithm is implemented in DSP (Digital Signal Processor) firmware and DOOCS (Distributed Object Oriented Control System) servers. The RF control system design objectives are discussed. Hardware and software design of the DSP based RF control are presented. (orig.)

Development and performance test of a new high power RF window in S-band PLS-II LINAC

Science.gov (United States)

Hwang, Woon-Ha; Joo, Young-Do; Kim, Seung-Hwan; Choi, Jae-Young; Noh, Sung-Ju; Ryu, Ji-Wan; Cho, Young-Ki

2017-12-01

A prototype of RF window was developed in collaboration with the Pohang Accelerator Laboratory (PAL) and domestic companies. High power performance tests of the single RF window were conducted at PAL to verify the operational characteristics for its application in the Pohang Light Source-II (PLS-II) linear accelerator (Linac). The tests were performed in the in-situ facility consisting of a modulator, klystron, waveguide network, vacuum system, cooling system, and RF analyzing equipment. The test results with Stanford linear accelerator energy doubler (SLED) have shown no breakdown up to 75 MW peak power with 4.5 μs RF pulse width at a repetition rate of 10 Hz. The test results with the current operation level of PLS-II Linac confirm that the RF window well satisfies the criteria for PLS-II Linac operation.

Microwave source development for 9 MeV RF electron LINAC for cargo scanning

International Nuclear Information System (INIS)

Yadav, V.; Chandan, Shiv; Tillu, A.R.; Bhattacharjee, D.; Chavan, R.B.; Dixit, K.P.; Mittal, K.C.; Gantayet, L.M.

2011-01-01

For cargo scanning, high energy X-rays are required. These X-rays can be generated from accelerated electrons. A 9 MeV Cargo scanning RF LINAC has been developed at ECIL, Hyderabad. The Microwave power source required for RF Linac is a klystron-based system generating 5.5 MW peak, 10 kW average, at 2.856 GHz. Various components required for microwave source were identified, procured, tested and integrated into the source. Microwave source was tested on water load, then it was connected to LINAC and RF conditioning and e-beam trials were successfully done. For operating the microwave source, a PC based remote handling system was also designed and developed for operating various power supplies and instruments of the microwave source, including the Klystron modulator, Signal generator and other devices. The accelerator operates in pulse mode, requiring synchronous operation of the Klystron modulator, RF driver amplifier and E-gun modulator. For this purpose, a synchronous trigger generator was designed and developed. This paper describes the development and testing of microwave source and its remote operating system. The results of beam trials are also discussed in this paper. (author)

Status of the RF-driven H− ion source for J-PARC linac

International Nuclear Information System (INIS)

Oguri, H.; Ohkoshi, K.; Ikegami, K.; Takagi, A.; Asano, H.; Ueno, A.; Shibata, T.

2016-01-01

For the upgrade of the Japan Proton Accelerator Research Complex linac beam current, a cesiated RF-driven negative hydrogen ion source was installed during the 2014 summer shutdown period, with subsequent operations commencing on September 29, 2014. The ion source has been successfully operating with a beam current and duty factor of 33 mA and 1.25% (500 μs and 25 Hz), respectively. The result of recent beam operation has demonstrated that the ion source is capable of continuous operation for approximately 1100 h. The spark rate at the beam extractor was observed to be at a frequency of less than once a day, which is an acceptable level for user operation. Although an antenna failure occurred during operation on October 26, 2014, no subsequent serious issues have occurred since then

Developmental efforts of RF collinear load for 10 MeV, 6 kW travelling wave Linac

International Nuclear Information System (INIS)

Kumar, Pankaj; Kumar, Harish; Soni, R.K.; Dwivedi, Jishnu; Thakurta, A.C.; Wanmode, Y.D.; Pareek, Prashant; Senthil Kumar, S; Shinde, R.S.

2015-01-01

RRCAT is developing a 10 MeV, 6 kW Travelling Wave Electron Linac for radiation processing applications. The remnant RF power from the Linac structure is taken out by output RF coupler and absorbed by the waveguide load. RF collinear load is an improved technique for absorption of the remnant RF power. It replaces the output RF coupler, RF window and waveguide load leading to reduction in size of magnetic elements and less transverse beam instabilities. In addition, it uses the remnant RF power to increase the electron beam energy. The collinear load consists of a number of copper cavities coated with microwave absorbing material at inner surfaces and brazed to the Linac structure at the end. Development of the collinear load has been started at RRCAT and a prototype low power collinear load using Kanthal (FeCrAl alloy) coating has been developed. Further works are going on the development of high power collinear load using FeSiAl alloy. The paper describes the development of the Kanthal based prototype low power collinear load as well as the works for the development of FeSiAl alloy based high power collinear load. (author)

The Development of the Linac Coherent Light Source RF Gun

International Nuclear Information System (INIS)

Dowell, D

2008-01-01

The Linac Coherent Light Source (LCLS) is the first x-ray laser user facility based upon a free electron laser (FEL) requiring extraordinary beam quality to saturate at 1.5 angstroms within a 100 meter undulator.[1] This new type of light source is using the last kilometer of the three kilometer linac at SLAC to accelerate the beam to an energy as high as 13.6 GeV and required a new electron gun and injector to produce a very bright beam for acceleration. At the outset of the project it was recognized that existing RF guns had the potential to produce the desired beam but none had demonstrated it. Therefore a new RF gun or at least the modification of an existing gun was necessary. The parameters listed in Table 1 illustrate the unique characteristics of LCLS which drive the requirements for the electron gun as given in Table 2. The gun beam quality needs to accommodate emittance growth as the beam is travels through approximately one kilometer of linac and two bunch compressors before reaching the undulator. These beam requirements were demonstrated during the recent commissioning runs of the LCLS injector and linac [2] due to the successful design, fabrication, testing and operation of the LCLS gun. The goal of this paper is to relate the technical background of how the gun was able to achieve and in some cases exceed these requirements by understanding and correcting the deficiencies of the prototype s-band RF photocathode gun, the BNL/SLAC/UCLA Gun III. This paper begins with a brief history and technical description of Gun III and the Gun Test Facility (GTF) at SLAC, and studies of the gun's RF and emittance compensation solenoid. The work at the GTF identified the gun and solenoid deficiencies, and helped to define the specifications for the LCLS gun. Section 1.1.5 describes the modeling used to compute and correct the gun RF fields and Section 1.1.6 describes the use of these fields in the electron beam simulations. The magnetic design and measurements of

Present status and future directions of the JAERI superconducting RF linac-based FEL

International Nuclear Information System (INIS)

Minehara, EJ.; Yamauchi, T.; Sugimori, M.; Sawamura, M.; Hajima, R.; Nagai, R.; Kikuzawa, N.; Nishimori, N.; Shizuma, T.

2000-01-01

The JAERI superconducting rf linac based FEL has successfully been lased to produce a 2.34kW FEL light and l00kW electron beam output in quasi continuous wave operation in February 2000. Twice larger output than the present program goal of 1kW was achieved to improve the optical out coupling method in the FEL optical resonator, the electron gun, and the electron beam optics in the JAERI FEL driver. As our next 2 years program goal is the 100kW class FEL light and a few MW class electron beam output in average, quasi continuous wave operation of the light and electron beam will be planned in the JAERI superconducting rf linac based FEL facility. Conceptual and engineering design options needed for such a very high power operation will be discussed to improve and to upgrade the existing facility. Finally, several applications, table-top superconducting rf linac based FELs, and an X-ray FEL R and D will be discussed as a next-five years program at JAERI-FEL laboratory. (author)

Improved temperature regulation of APS linac RF components

International Nuclear Information System (INIS)

Dortwegt, R.

1998-01-01

The temperature of the APS S-Band linac's high-power rf components is regulated by water from individual closed-loop deionized (DI) water systems. The rf components are all made of oxygen-free high-conductivity copper and respond quickly to temperature changes. The SLED cavities are especially temperature-sensitive and cause beam energy instabilities when the temperature is not well regulated. Temperature regulation better than ± 0.1 F is required to achieve good energy stability. Improvements in the closed-loop water systems have enabled them to achieve a regulation of ± 0.05 F over long periods. Regulation philosophy and equipment are discussed and numerical results are presented

Proton linac for hospital-based fast neutron therapy and radioisotope production

International Nuclear Information System (INIS)

Lennox, A.J.; Hendrickson, F.R.; Swenson, D.A.; Winje, R.A.; Young, D.E.

1989-09-01

Recent developments in linac technology have led to the design of a hospital-based proton linac for fast neutron therapy. The 180 microamp average current allows beam to be diverted for radioisotope production during treatments while maintaining an acceptable dose rate. During dedicated operation, dose rates greater than 280 neutron rads per minute are achievable at depth, DMAX = 1.6 cm with source to axis distance, SAD = 190 cm. Maximum machine energy is 70 MeV and several intermediate energies are available for optimizing production of isotopes for Positron Emission Tomography and other medical applications. The linac can be used to produce a horizontal or a gantry can be added to the downstream end of the linac for conventional patient positioning. The 70 MeV protons can also be used for proton therapy for ocular melanomas. 17 refs., 1 fig., 1 tab

Finite element thermal study of the Linac4 plasma generator

International Nuclear Information System (INIS)

Faircloth, D.; Kronberger, M.; Kuechler, D.; Lettry, J.; Scrivens, R.

2010-01-01

The temperature distribution and heat flow at equilibrium of the plasma generator of the rf-powered noncesiated Linac4 H - ion source have been studied with a finite element model. It is shown that the equilibrium temperatures obtained in the Linac4 nominal operation mode (100 kW rf power, 2 Hz repetition rate, and 0.4 ms pulse duration) are within material specifications except for the magnet cage, where a redesign may be necessary. To assess the upgrade of the Linac4 source for operation in the high-power operation mode of the Superconducting Proton Linac (SPL), an extrapolation of the heat load toward 100 kW rf power, 50 Hz repetition rate, and 0.4 ms pulse duration has been performed. The results indicate that a significant improvement of the source cooling is required to allow for operation in the high-power mode of SPL.

Finite element thermal study of the Linac4 plasma generator

Energy Technology Data Exchange (ETDEWEB)

Faircloth, D. [STFC, Rutherford Appleton Laboratory, Chilton, Oxon OX11 0QX (United Kingdom); Kronberger, M.; Kuechler, D.; Lettry, J.; Scrivens, R. [BE-ABP, Hadron Sources and Linacs, CERN, CH-1211 Geneva (Switzerland)

2010-02-15

The temperature distribution and heat flow at equilibrium of the plasma generator of the rf-powered noncesiated Linac4 H{sup -} ion source have been studied with a finite element model. It is shown that the equilibrium temperatures obtained in the Linac4 nominal operation mode (100 kW rf power, 2 Hz repetition rate, and 0.4 ms pulse duration) are within material specifications except for the magnet cage, where a redesign may be necessary. To assess the upgrade of the Linac4 source for operation in the high-power operation mode of the Superconducting Proton Linac (SPL), an extrapolation of the heat load toward 100 kW rf power, 50 Hz repetition rate, and 0.4 ms pulse duration has been performed. The results indicate that a significant improvement of the source cooling is required to allow for operation in the high-power mode of SPL.

The linac and booster RF systems for a dedicated injector for SPEAR

International Nuclear Information System (INIS)

Weaver, J.N.; Baird, S.; Baltay, M.; Borland, M.; Nuhn, H.D.; Safranek, J.; Chavis, C.; Emery, L.; Genin, R.D.; Hettel, R.; Morales, H.; Sebek, J.; Voss, J.; Wang, D.; Wiedemann, H.; Youngmann, B.; Miller, R.H.

1991-01-01

A 120 MeV, 2,856 MHz, TW linac, with a microwave gun, alpha magnet, and chopper, has been built at SSRL as a preinjector for and along with a 3 GeV booster synchrotron ring. The resulting injector will be available on demand to fill SPEAR, which is a storage ring now dedicated to synchrotron light production. The linac sections were purchased from China, the XK-5 klystrons were obtained surplus from SLAC, the modulators are a variation on those at SLAC and were built by SSRL, the alpha magnet and chopper were designed and built at SSRL and the microwave gun was designed and built in collaboration with Varian Associates. The RF system for the booster ring is similar to those at SPEAR and PEP and was built by SSRL. Some of the interesting mechanical and electrical details are discussed and the operating characteristics of the linac and ring RF system are highlighted

The linac and booster RF systems for a dedicated injector for SPEAR

International Nuclear Information System (INIS)

Weaver, J.N.; Baird, S.; Baltay, M.; Borland, M.; Nuhn, H.D.; Safranek, J.; Chavis, C.; Emery, L.; Genin, R.D.; Hettel, R.; Morales, H.; Sebek, J.; Voss, J.; Wang, H.; Wiedemann, H.; Youngmann, B.

1991-05-01

A 120 MeV, 2856 MHz, TW linac, with a microwave gun, alpha magnet, and chopper, has been built at SSRL as a preinjector for and along with a 3 GeV booster synchrotron ring. The resulting injector will be available on demand to fill SPEAR, which is a storage ring now dedicated to synchrotron light production. The linac sections were purchased from China, the XK-5 klystrons were obtained surplus from SLAC, the modulators are a variation on those at SLAC and were built by SSRL, the alpha magnet and chopper were designed and built at SSRL and the microwave gun was designed and built in collaboration with Varian Associates. The rf system for the booster ring is similar to those at SPEAR and PEP and was built by SSRL. Some of the interesting mechanical and electrical details are discussed and the operating characteristics of the linac and ring rf system are highlighted. 8 refs., 6 figs

The SSRL linacs for injection to the storage ring and rf gun testing

International Nuclear Information System (INIS)

Park, Sanghyun; Weaver, James N.

1996-01-01

The Stanford Synchrotron Radiation Laboratory (SSRL) operates two linac systems. One has three SLAC type linac sections powered by two klystrons for injection of electrons at 120 MeV into the booster ring, boosting the energy to 2.3 GeV to fill the SPEAR. After the ramping, the SPEAR stores up to 100 mA of the beam at 3.0 GeV. The preinjector consists of a thermionic RF gun, an alpha magnet, and a chopper along with focusing magnets. The other has one 10 foot section powered by the injector klystron for the testing of RF gun with photocathode, which is driven by a separate klystron. This paper describes present systems with their operational parameters, followed by plans for the upgrades and RF gun development efforts at the SSRL. (author)

Radiation protection studies for a high-power 160 MeV proton linac

CERN Document Server

Mauro, Egidio

2009-01-01

CERN is presently designing a new chain of accelerators to replace the present Proton Synchrotron (PS) complex: a 160 MeV room-temperature H− linac (Linac4) to replace the present 50 MeV proton linac injector, a 3.5 GeV Superconducting Proton Linac (SPL) to replace the 1.4 GeV PS Booster (PSB) and a 50 GeV synchrotron (named PS2) to replace the 26 GeV PS. Linac4 has been funded and the civil engineering work started in October 2008, whilst the SPL is in an advanced stage of design. Beyond injecting into the future 50 GeV PS, the ultimate goal of the SPL is to generate a 4 MW beam for the production of intense neutrino beams. The radiation protection design is driven by the latter requirement. This work summarizes the radiation protection studies conducted for Linac4. FLUKA Monte Carlo simulations, complemented by analytical estimates, were performed to evaluate the propagation of neutrons through the waveguide, ventilation and cable ducts placed along the accelerator, to estimate the radiological impact of ...

SRF and RF systems for LEReC Linac

Energy Technology Data Exchange (ETDEWEB)

Belomestnykh, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., NY (United States); Ben-Zvi, I. [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., NY (United States); Brutus, J. C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fedotov, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); McIntyre, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Polizzo, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Smith, K. [Brookhaven National Lab. (BNL), Upton, NY (United States); Than, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tuozzolo, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Veshcherevich, V. [Cornell Univ., Ithaca, NY (United States); Wu, Q. [Brookhaven National Lab. (BNL), Upton, NY (United States); Xiao, B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Xu, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zaltsman, A. [Brookhaven National Lab. (BNL), Upton, NY (United States)

2015-05-03

The Low Energy RHIC electron Cooling (LEReC) is under development at BNL to improve RHIC luminosity at low energies. It will consist of a short electron linac and two cooling sections, one for blue and one for yellow rings. For the first stage of the project, LEReC-I, we will install a 704 MHz superconducting RF cavity and three normal conducting cavities operating at 9 MHz, 704 MHz and 2.1 GHz. The SRF cavity will boost the electron beam energy up to 2 MeV. The warm cavities will be used to correct the energy spread introduced in the SRF cavity. The paper describes layouts of the SRF and RF systems, their parameters and status.

An energy recovery electron linac-on-ring collider

International Nuclear Information System (INIS)

Merminga, L.; Krafft, G.A.; Lebedev, V.A.; Ben-Zvi, I.

2000-01-01

We present the design of high-luminosity electron-proton/ion colliders in which the electrons are produced by an Energy Recovering Linac (ERL). Electron-proton/ion colliders with center of mass energies between 14 GeV and 100 GeV (protons) or 63 GeV/A (ions) and luminosities at the 10 33 (per nucleon) level have been proposed recently as a means for studying hadronic structure. The linac-on-ring option presents significant advantages with respect to: (1) spin manipulations (2) reduction of the synchrotron radiation load in the detectors (3) a wide range of continuous energy variability. Rf power and beam dump considerations require that the electron linac recover the beam energy. Based on extrapolations from actual measurements and calculations, energy recovery is expected to be feasible at currents of a few hundred mA and multi-GeV energies. Luminosity projections for the linac-ring scenario based on fundamental limitations are presented. The feasibility of an energy recovery electron linac-on-proton ring collider is investigated and four conceptual point designs are shown corresponding to electron to proton energies of: 3 GeV on 15 GeV, 5 GeV on 50 GeV and 10 GeV on 250 GeV, and for gold ions with 100 GeV/A. The last two designs assume that the protons or ions are stored in the existing RHIC accelerator. Accelerator physics issues relevant to proton rings and energy recovery linacs are discussed and a list of required R and D for the realization of such a design is presented

An rf modulated electron gun pulser for linacs

International Nuclear Information System (INIS)

Legg, R.; Hartline, R.

1991-01-01

Present linac injector designs often make use of sub-harmonic prebuncher cavities to properly bunch the electron beam before injection into a buncher and subsequent accelerating cavities. This paper proposes an rf modulated thermionic gun which would allow the sub-harmonic buncher to be eliminated from the injector. The performance parameters for the proposed gun are 120 kV operating voltage, macropulse duration-single pulse mode 2 nsec, multiple pulse mode 100 nsec, rf modularing frequency 500 MHz, charge per micropulse 0.4 nC, macropulse repetition frequency 10 Hz (max). The gun pulser uses a grid modulated planar triode to drive the gun cathode. The grid driver takes advantage of recently developed modular CATV rf drivers, high performance solid state pulser devices, and high-frequency fiber optic transmitters for telecommunications. Design details are presented with associated SPICE runs simulating operation of the gun

Radiation induced currents in MRI RF coils: application to linac/MRI integration

Science.gov (United States)

Burke, B.; Fallone, B. G.; Rathee, S.

2010-02-01

The integration of medical linear accelerators (linac) with magnetic resonance imaging (MRI) systems is advancing the current state of image-guided radiotherapy. The MRI in these integrated units will provide real-time, accurate tumor locations for radiotherapy treatment, thus decreasing geometric margins around tumors and reducing normal tissue damage. In the real-time operation of these integrated systems, the radiofrequency (RF) coils of MRI will be irradiated with radiation pulses from the linac. The effect of pulsed radiation on MRI radio frequency (RF) coils is not known and must be studied. The instantaneous radiation induced current (RIC) in two different MRI RF coils were measured and presented. The frequency spectra of the induced currents were calculated. Some basic characterization of the RIC was also done: isolation of the RF coil component responsible for RIC, dependence of RIC on dose rate, and effect of wax buildup placed on coil on RIC. Both the time and frequency characteristics of the RIC were seen to vary with the MRI RF coil used. The copper windings of the RF coils were isolated as the main source of RIC. A linear dependence on dose rate was seen. The RIC was decreased with wax buildup, suggesting an electronic disequilibrium as the cause of RIC. This study shows a measurable RIC present in MRI RF coils. This unwanted current could be possibly detrimental to the signal to noise ratio in MRI and produce image artifacts.

The split coaxial linac structure and its RF modes

International Nuclear Information System (INIS)

Mueller, R.W.

1989-01-01

The Split Coaxial Cavity structure has been invented and applied for the first time in the heavy-ion RFQ linac MAXILAC of GSI. It has an ideally flat RF voltage distribution and a good power economy. From another standpoint, it is a member of the small family of linac structures where the two modes, the wanted one and the unflatness mode, are clearly and strictly separable. The unflatness or ''Q Line'' mode is analyzed in more detail in this paper. It is necessary for the understanding of the interaction of the beam with the cavity, possible beam instabilities resulting from it, and for curing these instabilities with the chance of obtaining improved beams. (orig.)

Design and development of R.F. LINAC accelerator components

International Nuclear Information System (INIS)

Abhay Kumar; Guha, S.; Balasubramaniam, R.; Jawale, S.B.

2003-01-01

Full text: Radio frequency linear accelerator, a high power electron LINAC technology, is being developed at BARC. These accelerators are considered to be the most compact and effective for a given power capacity. Important application areas of this LINAC include medical sterilization, food preservation, pollution control, semiconductor industries, radiation therapy and material science. Center for Design and Manufacture (CDM), BARC has been entrusted with the design, development and manufacturing of various mechanical components of the accelerator. Most critical and precision components out of them are Diagnostic chamber, Faraday cup, Drift tube and R.F. cavities. This paper deals with the design aspects in respect of Ultra high vacuum compatibility and the mechanism of operation. Also this paper discusses the state-of-art technology for machining of intricate contour using specially designed poly crystalline diamond tool and the inspection methodology developed to minimize the measurement errors on the machined contour. Silver brazing technique employed to join the LINAC cavities is also described in detail

Assembly and RF Tuning of the Linac4 RFQ at CERN

CERN Document Server

Rossi, C; Hansen, J; Lallement, JB; Lombardi, AM; Pugnat, D; Vandoni, G; Timmins, M; Vretenar, M; Mathot, S; Piquet, O; Novo, J; Le Noa, Y; France, A; Desmons, M

2013-01-01

The fabrication of Linac4 is progressing at CERN with the goal of making a 160 MeV H- beam available to the LHC injection chain as from 2015. In the Linac4 the first stage of beam acceleration, after its extraction from the ion source, is provided by a Radiofrequency Quadrupole accelerator (RFQ), operating at the RF frequency of 352.2 MHz and which accelerates the ion beam to the energy of 3 MeV. The RFQ, made of three modules, one meter each, is of the four-vane kind, has been designed in the frame of a collaboration between CERN and CEA and has been completely machined and assembled at CERN. The paper describes the assembly of the RFQ structure and reports the results of RF low power measurements, in order to achieve the required accelerating field flatness within 1% of the nominal field profile.

Overview of the Spallation Neutron Source Linac Low-Level RF Control System

CERN Document Server

Champion, Mark; Doolittle, Lawrence; Kasemir, Kay-Uwe; Ma, Hengjie; Piller, Maurice; Ratti, Alessandro

2005-01-01

The design and production of the Spallation Neutron Source Linac Low-Level RF control system is complete, and installation will be finished in Spring 2005. The warm linac beam commissioning run in Fall 2004 was the most extensive test to date of the LLRF control system, with fourteen (of an eventual 96) systems operating simultaneously. In this paper we present an overview of the LLRF control system, the experience in designing, building and installing the system, and operational results.

SRF LINAC for future extension of the PEFP

Energy Technology Data Exchange (ETDEWEB)

Kim, Han Sung; Kwon, Hyeok Jung; Seol, Kyoung Tae; Jang, Ji Ho; Cho, Yong Sub [Proton Engineering Frontier Project, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-04-15

A study on the superconducting RF linac is underway in order to increase the beam energy up to 1 GeV by extending the Proton Engineering Frontier Project (PEFP) 100-MeV linac. The operating frequency of the PEFP superconducting linac (SCL) is 700 MHz, which is determined by the fact that the frequency of the existing normal conducting linac is 350 MHz. A preliminary study on the beam dynamics showed that two types of cavities with geometrical betas of 0.50 and 0.74 could cover the entire energy range from 100 MeV to 1 GeV. An inductive output tube (IOT) based RF system is under consideration as a high-power RF source for the SCL due to its low operating voltage and high efficiency. As a prototyping activity for a reduced beta cavity, a five-cell cavity with a geometrical beta of 0.42 was designed and fabricated. A vertical test of the prototype cavity at low temperatures was performed to check the performance of the cavity. The design study and the prototyping activity for the PEFP SCL will be presented in this paper.

SRF LINAC for future extension of the PEFP

International Nuclear Information System (INIS)

Kim, Han Sung; Kwon, Hyeok Jung; Seol, Kyoung Tae; Jang, Ji Ho; Cho, Yong Sub

2014-01-01

A study on the superconducting RF linac is underway in order to increase the beam energy up to 1 GeV by extending the Proton Engineering Frontier Project (PEFP) 100-MeV linac. The operating frequency of the PEFP superconducting linac (SCL) is 700 MHz, which is determined by the fact that the frequency of the existing normal conducting linac is 350 MHz. A preliminary study on the beam dynamics showed that two types of cavities with geometrical betas of 0.50 and 0.74 could cover the entire energy range from 100 MeV to 1 GeV. An inductive output tube (IOT) based RF system is under consideration as a high-power RF source for the SCL due to its low operating voltage and high efficiency. As a prototyping activity for a reduced beta cavity, a five-cell cavity with a geometrical beta of 0.42 was designed and fabricated. A vertical test of the prototype cavity at low temperatures was performed to check the performance of the cavity. The design study and the prototyping activity for the PEFP SCL will be presented in this paper.

A hospital-based proton linac for neutron therapy and radioisotope production

International Nuclear Information System (INIS)

Lennox, A.J.

1988-10-01

Fermilab's Alvarez proton linac has been used routinely for neutron therapy since 1976. The Neutron Therapy Facility (NTF) operates in a mode parasitic to the laboratory's high energy physics program, which uses the linac as an injector for a synchrotron. Parasitic operation is possible because the linac delivers /approximately/1.2 /times/ 10 13 protons per pulse at a 15 Hz rate, while the high energy physics program requires beam at a rate not greater than 0.5 Hz. Protons not needed for physics experiments strike a beryllium target to produce neutrons for neutron therapy. Encouraging clinical results from NTF have led to a study of the issues involved in providing hospitals with a neutron beam of the type available at Fermilab. This paper describes the issues addressed by that study. 12 refs., 1 fig., 1 tab

Linac4 45 keV Proton Beam Measurements

CERN Document Server

Bellodi, G; Hein, L M; Lallement, J-B; Lombardi, A M; Midttun, O; Scrivens, R; Posocco, P A

2013-01-01

Linac4 is a 160 MeV normal-conducting H- linear accelerator, which will replace the 50 MeV proton Linac2 as injector for the CERN proton complex. Commissioning of the low energy part - comprising the H - source, a 45 keV Low Energy Beam Transport line (LEBT), a 3 MeV Radiofrequency Quadrupole (RFQ) and a Medium Energy Beam Transport (MEBT) - will start in fall 2012 on a dedicated test stand installation. In preparation to this, preliminary measurements were taken using a 45 keV proton source and a temporary LEBT setup, with the aim of characterising the output beam by comparison with the predictions of simulations. At the same time this allowed a first verification of the functionalities of diagnostics instrumentation and acquisition software tools. Measurements of beam profile, emittance and intensity were taken in three different setups: right after the source, after the first and after the second LEBT solenoids respectively. Particle distributions were reconstructed from emittance scan...

Development of the Medium Energy Linac Systems

International Nuclear Information System (INIS)

Jang, Ji Ho; Kwon, Hyeok Jung; Kim, Dae Il; Kim, Han Sung; Park, Bum Sik; Seol, Kyung Tae; Song, Young Gi; Yun, Sang Pil; Cho, Yong Sub; Hong, In Seok

2008-05-01

The main purpose of this project is developing 100-MeV proton linear accelerator (linac) for proton engineering frontier project (PEFP). In the first phase of the PEFP, the development of the 20-MeV linac has successfully finished. Hence the work scope of this project is designing the linac to accelerate proton beams from 20-MeV up to 100-MeV, fabricating the linac up to 45 MeV, fabricating one set of the medium energy beam transport (MEBT) tank, and developing the low level radio frequency (LLRF) system and the control system. The basic role of the new proton accelerator is accelerating 20-mA proton beams from 20 MeV up to 100 MeV. The first step of the design procedure is optimizing and determining the accelerator parameters. The beam loss is also main concern in the design stage. The drift tube (DT) and the quadrupole magnets are designed to be optimized to the new linac design. The other purpose is confirming the new design by fabricating and tuning the drift tube linac (DTL). The 20MeV proton beam divided into two directions. One is supplying the beams to user group by turning on the 45-degree bending magnet. The other is guided into the 100-MeV DTL by tuning off the dipole magnet. That is why the PEFP MEBT located after 20-MeV DTL. The MEBT is realized as two small DTL tanks with three cells and a 45-degree bending magnet. The fabrication of one MEBT tank is another purpose of this project. The other purposes of this project is developing the LLRF system to control the RF signal and control system to monitor and control the vacuum system, magnet power supply, etc

Numerical studies and measurements on the side-coupled drift tube linac (SCDTL) accelerating structure

International Nuclear Information System (INIS)

Picardi, L.; Ronsivalle, C.; Spataro, B.

2000-01-01

The 3 GHz linac section designed for the low energy (7-65 MeV) part of TOP (therapy oncological protons) linac (Picardi et al., 1997, 1996), operating at 3 GHz frequency and in π/2 mode, consists of eight modules of the structure SCDTL (side-coupled drift tube linac). The first module is designed to accelerate 7 MeV protons up to 13.4 MeV, and a prototype is presently under construction. Electromagnetic field calculations of the non-axisymmetric cavities carried out by using MAFIA 3D code (Weiland, 1986) gave the RF wall losses and the full mode spectrum. Two prototypes, an aluminium model of the first quintuplet and a copper model of the last triplet of the module, were built in order to check the complex 3D properties of the structure, and to refine the tuning procedure. This paper reports the results of the 3D numerical simulations about the RF properties of the first module and of some RF measurements on the prototypes. The beam dynamics study results in the SCDTL section are discussed as well

Radio frequency linear accelerators for NDT applications: Basic overview of RF linacs

International Nuclear Information System (INIS)

Hansen, H.J.

1998-01-01

High energy X-ray radiography can be an important part of a quality control program. In this article the author will present an overview of the technology found in a typical high energy X-ray source, the radio frequency (RF) linear accelerator. In NDT, linacs are used primarily for the inspection of thick sections of materials. Linacs are also used in applications such as high energy computed tomography of specimens greater than 1 m thick and cargo container inspection. Recent developments in reliable portable linacs are opening up other applications such as field inspection of pipelines, ships, bridges, and other civil infrastructure. The replacement of isotopes (such as Co-60) by the linac is an area for growth in the future. The shorter exposure times, improved image capabilities, and greatly reduced regulatory requirements of the linac make a persuasive argument for the replacement of isotopes with a portable linac. The linacs discussed here are those with X-ray energies from 1 to 20 MeV intended for use in NDT applications. The discussion will be in very broad terms; it will be impossible to discuss every variation in linac design. In addition, some topics have been necessarily simplified to increase the comprehensibility for a wider audience

Design of a 120 MeV $H^{-}$ Linac for CERN High-Intensity Applications

CERN Document Server

Gerigk, F

2002-01-01

The SPL (Superconducting Proton Linac) study at CERN foresees the construction of a 2.2 GeV linac as a high beam-power driver for applications such as a second-generation radioactive ion beam facility or a neutrino superbeam. At the same time such a high-performance injector would both modernize and improve the LHC injection chain. The 120 MeV normal-conducting section of the SPL could be used directly in a preliminary stage for H- charge-exchange injection into the PS Booster. This would increase the proton flux to the CERN experiments while also improving the quality and reliability of the beams for the LHC. The 120 MeV linac consists of a front-end, a conventional Drift Tube Linac (DTL) to 40 MeV and a Cell Coupled Drift Tube Linac (CCDTL) to the full energy. All the RF structures will operate at 352 MHz, using klystrons and RF equipment recovered from the LEP collider. This paper concentrates on the design of the 3 to 120 MeV section. It introduces the design criteria for high-stability beam optics and th...

Rf breakdown studies in room temperature electron linac structures

International Nuclear Information System (INIS)

Loew, G.A.; Wang, J.W.

1988-05-01

This paper is an overall review of studies carried out by the authors and some of their colleagues on RF breakdown, Field Emission and RF processing in room temperature electron linac structure. The motivation behind this work is twofold: in a fundamental way, to contribute to the understanding of the RF breakdown phenomenon, and as an application, to determine the maximum electric field gradient that can be obtained and used safely in future e/sup +-/ linear colliders. Indeed, the next generation of these machines will have to reach into the TeV (10 12 eV) energy range, and the accelerating gradient will be to be of the crucial parameters affecting their design, construction and cost. For a specified total energy, the gradient sets the accelerator length, and once the RF structure, frequency and pulse repetition rate are selected, it also determines the peak and average power consumption. These three quantities are at the heart of the ultimate realizability and cost of these accelerators. 24 refs., 19 figs., 4 tabs

A fifth harmonic rf bunch monitor for the ANL-APS electron linac

International Nuclear Information System (INIS)

Nassiri, A.; Grelick, A.

1993-01-01

The function of a fifth harmonic (14.28 GHz) bunch monitor is to provide a signal which is proportional to the electron beam bunch size. The monitoring of the rf power signal at 14.28 GHz enables the operator to optimize the rf bunching of the beam at the end of the first accelerating section where the full bunching has been formed and remains mainly constant in size throughout the rest of the electron linac. A modified version of the SLAC original bunch monitor has been fabricated and its rf properties measured. This paper describes the design and the initial measurement results

A fifth harmonic RF bunch monitor for the ANL-APS electron linac

International Nuclear Information System (INIS)

Nassiri, A.; Grelick, A.

1993-01-01

The function of a fifth harmonic (14.28 GHz) bunch monitor is to provide a signal which is proportional to the electron beam bunch size. The monitoring of the rf power signal at 14.28 GHz enables the operator to optimize the rf bunching of the beam at the end of the first accelerating section where the full bunching has been formed and remains mainly constant in size throughout the rest of the electron linac. A modified version of the SLAC original bunch monitor has been fabricated and its rf properties measured. This paper describes the design and the initial measurements results

Prototype Digital Beam Position and Phase Monitor for the 100-MeV Proton Linac of PEFP

CERN Document Server

Yu In Ha; Kim, Sung-Chul; Park, In-Soo; Park, Sung-Ju; Tae Kim, Do

2005-01-01

The PEFP (Proton Engineering Frontier Project) at the KAERI (Korea Atomic Energy Research Institute) is building a high-power proton linear accelerator aiming to generate 100-MeV proton beams with 20-mA peak current (pulse width and max. repetition rate of 1 ms and 120 Hz respectively). We are developing a prototype digital BPPM (Beam Position and Phase Monitor) for the PEFP linac utilizing the digital technology with field programmable gate array (FPGA). The RF input signals are down converted to 10 MHz and sampled at 40 MHz with 14-bit ADC to produce I and Q data streams. The system is designed to provide a position and phase resolution of 0.1% and 0.1? RMS respectively. The fast digital processing is networked to the EPICS-based control system with an embedded processor (Blackfin). In this paper, the detailed description of the prototype digital beam position and phase monitor will be described with the performance test results.

Design of 250-MW CW RF system for APT

International Nuclear Information System (INIS)

Rees, D.

1997-01-01

The design for the RF systems for the APT (Accelerator Production of Tritium) proton linac will be presented. The linac produces a continuous beam power of 130 MW at 1300 MeV with the installed capability to produce up to a 170 MW beam at 1700 MeV. The linac is comprised of a 350 MHz RFQ to 7 MeV followed in sequence by a 700 MHz coupled-cavity drift tube linac, coupled-cavity linac, and superconducting (SC) linac to 1700 MeV. At the 1700 MeV, 100 mA level the linac requires 213 MW of continuous-wave (CW) RF power. This power will be supplied by klystrons with a nominal output power of 1.0 MW. 237 kystrons are required with all but three of these klystrons operating at 700 MHz. The klystron count includes redundancy provisions that will be described which allow the RF systems to meet an operational availability in excess of 95 percent. The approach to achieve this redundancy will be presented for both the normal conducting (NC) and SC accelerators. Because of the large amount of CW RF power required for the APT linac, efficiency is very important to minimize operating cost. Operation and the RF system design, including in-progress advanced technology developments which improve efficiency, will be discussed. RF system performance will also be predicted. Because of the simultaneous pressures to increase RF system reliability, reduce tunnel envelope, and minimize RF system cost, the design of the RF vacuum windows has become an important issue. The power from a klystron will be divided into four equal parts to minimize the stress on the RF vacuum windows. Even with this reduction, the RF power level at the window is at the upper boundary of the power levels employed at other CW accelerator facilities. The design of a 350 MHz, coaxial vacuum window will be presented as well as test results and high power conditioning profiles. The transmission of 950 kW, CW, power through this window has been demonstrated with only minimal high power conditioning

Radioisotope production linac

International Nuclear Information System (INIS)

Stovall, J.E.; Hansborough, L.D.; O'Brien, H.A.

1981-01-01

A 70-MeV proton beam would open a new family of medical radioisotopes (including the important 123 I) to wide application. A 70-MeV, 500-μA linac is described, based on recent innovations in accelerator technology. It would be 27.3 m long, cost approx. $6 million, and the cost of power deposited in the radioisotope-production target is comparable to existing cyclotrons. By operating the rf-power system to its full capability, the same accelerator is capable of producing a 1140-μA beam, and the cost per beam watt on the target is less than half that of comparable cyclotrons. The technology to build such a linac is in a mature stage of developmnt, ready for use by industry

Beam Dynamics Simulation of Photocathode RF Electron Gun at the PBP-CMU Linac Laboratory

Science.gov (United States)

Buakor, K.; Rimjaem, S.

2017-09-01

Photocathode radio-frequency (RF) electron guns are widely used at many particle accelerator laboratories due to high quality of produced electron beams. By using a short-pulse laser to induce the photoemission process, the electrons are emitted with low energy spread. Moreover, the photocathode RF guns are not suffered from the electron back bombardment effect, which can cause the limited electron current and accelerated energy. In this research, we aim to develop the photocathode RF gun for the linac-based THz radiation source. Its design is based on the existing gun at the PBP-CMU Linac Laboratory. The gun consists of a one and a half cell S-band standing-wave RF cavities with a maximum electric field of about 60 MV/m at the centre of the full cell. We study the beam dynamics of electrons traveling through the electromagnetic field inside the RF gun by using the particle tracking program ASTRA. The laser properties i.e. transverse size and injecting phase are optimized to obtain low transverse emittance. In addition, the solenoid magnet is applied for beam focusing and emittance compensation. The proper solenoid magnetic field is then investigated to find the optimum value for proper emittance conservation condition.

RF Group Annual Report 2011

CERN Document Server

Angoletta, M E; Betz, M; Brunner, O; Baudrenghien, P; Calaga, R; Caspers, F; Ciapala, E; Chambrillon, J; Damerau, H; Doebert, S; Federmann, S; Findlay, A; Gerigk, F; Hancock, S; Höfle, W; Jensen, E; Junginger, T; Liao, K; McMonagle, G; Montesinos, E; Mastoridis, T; Paoluzzi, M; Riddone, G; Rossi, C; Schirm, K; Schwerg, N; Shaposhnikova, E; Syratchev, I; Valuch, D; Venturini Delsolaro, W; Völlinger, C; Vretenar, M; Wuensch, W

2012-01-01

The highest priority for the RF group in 2011 was to contribute to a successful physics run of the LHC. This comprises operation of the superconducting 400 MHz accelerating system (ACS) and the transverse damper (ADT) of the LHC itself, but also all the individual links of the injector chain upstream of the LHC – Linac2, the PSB, the PS and the SPS – don’t forget that it is RF in all these accelerators that truly accelerates! A large variety of RF systems had to operate reliably, often near their limit. New tricks had to be found and implemented to go beyond limits; not to forget the equally demanding operation with Pb ions using in addition Linac3 and LEIR. But also other physics users required the full attention of the RF group: CNGS required in 2011 beams with very short, intense bunches, AD required reliable deceleration and cooling of anti-protons, Isolde the post-acceleration of radioactive isotopes in Rex, just to name a few. In addition to the supply of beams for physics, the RF group has a num...

Status of RF superconductivity at Argonne

Energy Technology Data Exchange (ETDEWEB)

Shepard, K.W.

1989-01-01

Development of a superconducting (SC) slow-wave structures began at Argonne National Laboratory (ANL) in 1971, and led to the first SC heavy-ion linac (ATLAS - the Argonne Tandem-Linac Accelerating System), which began regularly scheduled operation in 1978. To date, more than 40,000 hours of bean-on target operating time has been accumulated with ATLAS. The Physics Division at ANL has continued to develop SC RF technology for accelerating heavy-ions, with the result that the SC linac has, up to the present, has been in an almost continuous process of upgrade and expansion. It should be noted that this has been accomplished while at the same time maintaining a vigorous operating schedule in support of the nuclear and atomic physics research programs of the division. In 1987, the Engineering Physics Division at ANL began development of SC RF components for the acceleration of high-brightness proton and deuterium beams. This work has included the evaluation of RF properties of high-{Tc} oxide superconductors, both for the above and for other applications. The two divisions collaborated while they worked on several applications of RF SC, and also worked to develop the technology generally. 11 refs., 6 figs.

rf conditioning and breakdown analysis of a traveling wave linac with collinear load cells

Science.gov (United States)

Chen, Qushan; Hu, Tongning; Qin, Bin; Xiong, Yongqian; Fan, Kuanjun; Pei, Yuanji

2018-04-01

Huazhong University of Science and Technology (HUST) has built a compact linac-based terahertz free electron laser (THz-FEL) prototype. In order to achieve compact structure, the linac uses collinear load cells instead of conventional output coupler to absorb remanent power at the end of linac. The new designed structure is confronted with rf breakdown problem after a long time conditioning process, so we tried to figure out the breakdown site in the linac. Without transmitted signal, we propose two methods to analyze the breakdown site mainly based on the forward and the reflected power signals. One method focuses on the time relationship of the two signals while the other focuses on the amplitude. Both the two methods indicate the breakdown events happened at the end of the linac and more likely in the first or the second load cell.

rf conditioning and breakdown analysis of a traveling wave linac with collinear load cells

Directory of Open Access Journals (Sweden)

Qushan Chen

2018-04-01

Full Text Available Huazhong University of Science and Technology (HUST has built a compact linac-based terahertz free electron laser (THz-FEL prototype. In order to achieve compact structure, the linac uses collinear load cells instead of conventional output coupler to absorb remanent power at the end of linac. The new designed structure is confronted with rf breakdown problem after a long time conditioning process, so we tried to figure out the breakdown site in the linac. Without transmitted signal, we propose two methods to analyze the breakdown site mainly based on the forward and the reflected power signals. One method focuses on the time relationship of the two signals while the other focuses on the amplitude. Both the two methods indicate the breakdown events happened at the end of the linac and more likely in the first or the second load cell.

Progress of the Moscow Meson Factory linac RF phase and amplitude control system

International Nuclear Information System (INIS)

Sharamentov, S.I.; Edachev, V.V.; Kvasha, A.I.; Belov, A.D.; Kuznetsov, V.V.

1992-01-01

The updated configuration of the MMF linac rf phase and amplitude control systems are presented. The structure of systems, controlling devices and specific feedback controller with Smith compensation and simulated feed-forward control loop are described. (Author) 2 refs., 5 figs

Design of a Marx-Topology Modulator for FNAL Linac

Energy Technology Data Exchange (ETDEWEB)

Butler, T. A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Garcia, F. G. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Kufer, M. R. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Pfeffer, H. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Wolff, D. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

2015-04-28

The Fermilab Proton Improvement Plan (PIP) was formed in late 2011 to address important and necessary upgrades to the Proton Source machines (Injector line, Linac and Booster). The goal is to increase the proton flux by doubling the Booster beam cycle rate while maintaining the same intensity per cycle, the same uptime, and the same residual activation in the enclosure. For the Linac, the main focus within PIP is to address reliability. One of the main tasks is to replace the present hard-tube modulator used on the 200 MHz RF system. Plans to replace this high power system with a Marx-topology modulator, capable of providing the required waveform shaping to stabilize the accelerating gradient and compensate for beam loading, will be presented, along with development data from the prototype unit.

Present and next steps of the JAERI superconducting rf linac based FEL program

International Nuclear Information System (INIS)

Minehara, E.J.; Yamauchi, T.; Sugimoto, M.

2000-01-01

The JAERI superconducting rf linac based FEL has successfully been lased to produce a 0.3 kW FEL light and 100 kW or larger electron beam output in quasi continuous wave operation in 1999. The 1 kW class output as our present program goal will be achieved to improve the optical out coupling method in the FEL optical resonator, the electron gun, and the electron beam optics in the JAERI FEL driver. As our next 5 year program goal is the 100 kW class FEL light and a few tens MW class electron beam output in average, quasi continuous wave operation of the light and electron beam will be planned in the JAERI superconducting rf linac based FEL facility. Conceptual design options needed for such a very high power operation and shorter wavelength light sources will be discussed to improve and to upgrade the exciting facility. (author)

Superconducting linac

International Nuclear Information System (INIS)

Bollinger, L.M.; Shepard, K.W.; Wangler, T.P.

1978-01-01

This project has two goals: to design, build, and test a small superconducting linac to serve as an energy booster for heavy ions from an FN tandem electrostatic accelerator, and to investigate various aspects of superconducting rf technology. The main design features of the booster are described, a status report on various components (resonators, rf control system, linac control system, cryostats, buncher) is given, and plans for the near future are outlined. Investigations of superconducting-linac technology concern studies on materials and fabrication techniques, resonator diagnostic techniques, rf-phase control, beam dynamics computer programs, asymmetry in accelerating field, and surface-treatment techniques. The overall layout of the to-be-proposed ATLAS, the Argonne Tandem-Linac Accelerator System, is shown; the ATLAS would use superconducting technology to produce beams of 5 to 25 MeV/A. 6 figures

Development of the High Energy Linac Systems

International Nuclear Information System (INIS)

Cho, Yong Sub; Kwon, Hyeok Jung; Kim, Han Sung; Chung, Byung Chul; Jang, Ji Ho; Gao, Changgi; Li, Yingmin; Sun, An; Tang, Yazhe; Zhang, Lipoing; Hwang, Yong Seok

2008-05-01

The main purpose of this project is studying the extension plan of the proton engineering frontier project (PEFP) 100-MeV Linac. It includes three categories. One is studying operation plan of the PEFP linac and its extended accelerators, and developing a distribution system of 100-MeV proton beams with a laser striping. Other is designing superconducting RF (SRF) modules and fabricating and testing a copper cavity model. The other is designing a rapid cycling synchrotron (RCS). The operation scheme of the PEFP linac is related to the optimization in the operation of the 100-MeV linac, 200-MeV SRF, and RCS. We studied several operational method to increase the validity of the accelerators. The beam distribution system has two roles. One is supplying proton beams of 100 MeV to the user group. The laser stripping of the negative hydrogen atoms is used in this case. The other beams are directed to the next high energy accelerators. This study contributes to increase the availability of the proton beams. The SRF is one of candidates to extend the PEFP linac system. Since the accelerating gradient of the SRF is much higher than the normal conducting accelerator, a lot of institutes over the world are developing the SRF structure. Main purposes are designing an SRF module, fabricating and testing an copper model which has similar material properties as Nb of the usual SRF cavity material. The RCS is a synchrotron whose injector is the PEFP 100-MeV linac. Main purposes are determining the lattice structure, studying the fast and slow extraction system, simulating beam behavior in the designed synchrotron. The RCS will be used as the spallation neutron source and tools in the basic and applied science including medical application

Hearthfire design base for the high current low velocity rf linac

International Nuclear Information System (INIS)

Burke, R.J.; Khoe, T.K.; Kustom, R.L.; Martin, R.L.; Moretti, A.

1977-01-01

The particle beam parameters needed for inertial fusion can be achieved with conventional accelerator technology if heavy ion machines attain the level of performance of the most intense high energy proton machines. Many of the problems posed by this goal pertain to the low energy portions of the accelerator system. In particular, the implied particle current in the rf linac is 10 3 --10 4 times the values achieved with existing heavy ion machines. Much of this discrepancy is simply attributable to the great differences between the design considerations relevant to accelerators for fusion and those which have determined the performance of the existing machines. The basic concept chosen at Argonne National Laboratory is cavities containing single drift tubes mounted on lambda/4 supports. Such structures pose the least problem for the beam transport system, and one cavity is placed between adjacent quadrupole magnets. The average voltage gain of the first cells of the low velocity section is moderate; and, although probably acceptable and improved by the end of the 10 MV section, the low initial gain adds to the motivation provided by the transport problem to increase the preinjector voltage substantially above 750 kV

Sci-Thurs PM: Delivery-08: Investigation of the source of RF noise from a modulator for an MR-linac project.

Science.gov (United States)

Lamey, M; Burke, B; Rathee, S; Fallone, B G; Carlone, M

2008-07-01

The next significant step in the advancement of IGRT is the integration of an MRI with a linac. The MRI-linac will provide images with exquisite soft tissue contrast in real-time during treatment. A possible problem associated with the proposed integration is the RF noise generated by the linac. This noise could interfere with the received signals of the MRI producing deleterious effects in the image quality. The work herein is concerned with understanding the processes involved in the RF noise production and the magnitude and frequency of this RF noise in the modulator of a linac. A software programming environment, MultiSIM, was used to model the electronic components of a modulator. Several Current and Voltage waveforms from the modulator were measured with an oscilloscope and compared with the corresponding results from the modulator model for validation. Finally, RF noise generated by the modulator was measured using field probes, which permits the frequency components of the measured and simulated modulator waveforms to be compared with the measured RF noise. The modeled PFN charging current and voltage, and klystron current show good agreement with measurements, with the exception of the tail of the klystron voltage signal. Once the model has been validated in both the time and frequency domains, future work will entail predicting pulse shape changes when, and if, modifications to the modulator are made. Specifically, modifications will be made which shift and/or reduce the RF noise in the frequency range of interest for a 0.2T MRI. © 2008 American Association of Physicists in Medicine.

Status of RF superconductivity at Argonne

International Nuclear Information System (INIS)

Shepard, K.W.

1989-01-01

Development of a superconducting (SC) slow-wave structures began at Argonne National Laboratory (ANL) in 1971, and led to the first SC heavy-ion linac (ATLAS - the Argonne Tandem-Linac Accelerating System), which began regularly scheduled operation in 1978. To date, more than 40,000 hours of bean-on target operating time has been accumulated with ATLAS. The Physics Division at ANL has continued to develop SC RF technology for accelerating heavy-ions, with the result that the SC linac has, up to the present, has been in an almost continuous process of upgrade and expansion. It should be noted that this has been accomplished while at the same time maintaining a vigorous operating schedule in support of the nuclear and atomic physics research programs of the division. In 1987, the Engineering Physics Division at ANL began development of SC RF components for the acceleration of high-brightness proton and deuterium beams. This work has included the evaluation of RF properties of high-T c oxide superconductors, both for the above and for other applications. The two divisions collaborated while they worked on several applications of RF SC, and also worked to develop the technology generally. 11 refs., 6 figs

Microprocessor-based control for independently-phased RF linac cavities

International Nuclear Information System (INIS)

Dawson, J.W.

1979-01-01

A microprocessor based system has been built to control the RF amplifiers associated with independently phased linac cavities. The system has an 8080A at each amplifier station, together with associated ROM, RAM, I/O, etc. At a central NOVA 3 computer an additional 8080A system is incorporated in the interface to the NOVA I/O bus. The NOVA interface is connected by a bus of eighteen twisted pairs to each amplifier station, providing bilateral transmission between each station and the NOVA. The system architecture, bus protocol, and operating characteristics are described

Microwave matching and tuning on the 20-MeV medical electron linac with feedback of rf power

International Nuclear Information System (INIS)

Yuan-ling, Wang

1983-01-01

This article describes the 20 Mev medical electron linac at Jiangsu Tumour Hospital. In the linac, feedback of rf power is used. In the linac with feedback (or with the resonator) the reflection affects the energy gain of the electron and the performance of the accelerator. By means of the theory of the traveling wave resonator, the field multiplication factor and the reflection coefficients inside and outside the feedback ring are calculated. The bands of the linacs without and with feedback are measured. In order to achieve a desirable band in front of the load (i.e. outside the feedback ring) a matching iris is added. After the linac with feedback has been matched, the band is given

Software of the System Protection for the PEFP 20MeV Proton Linac

International Nuclear Information System (INIS)

Song, Young-Gi; Hong, In-Seok; Cho, Yong-Sub

2007-01-01

A 20 MeV proton linear accelerator (linac) has been developed at Proton Engineering Frontier Project (PEFP). A 20 MeV linac consists of 50 keV proton injector, 3 MeV radio frequency quadrupole (RFQ), and 20 MeV drift tube linac (DTL). PEFP control system is developed with several sub-systems (e.g. machine control, diagnostic control, timing control, and interlock systems). These systems have each EPICS based control system which provides a network-based real time distributed control. For stable and harmonic operation, we had developed sequential logic by using state notation language (SNL) and database records with alarm fields for warning signal. The various control system can drop a transmission rate of the control network traffic. We need to manage control signals by a control network gateway and protect values of control servers by security management. In this paper, the stabilization methods of the control signals are described and the results of the stabilized signals are presented

A compact rf driven H- ion source for linac injection

International Nuclear Information System (INIS)

Rymer, J.P.; Engeman, G.A.; Hamm, R.W.; Potter, J.M.

1991-01-01

A compact rf driven H - ion source has been developed for use as an injector for the AccSys radio frequency quadrupole (RFQ) linacs. A multicusp magnetic bucket geometry developed at Lawrence Berkeley Laboratory confines the plasma created by an antenna driven by 35 kW (peak) of pulsed rf power at 1.8 MHz. A three electrode system is used to extract and accelerate the H - beam, which is then focused into the RFQ by an einzel lens. Permanent magnets in the extraction region sweep electrons onto the second electrode at energies up to half of the full acceleration voltage. A fast pulsed valve allows the hydrogen gas supply to be pulsed, thus minimizing the average gas flow rate into the system. The design features and performance data from the prototype are discussed

Design development of the SCDTL structure for the TOP linac

CERN Document Server

Picardi, L; Spataro, B

1999-01-01

The Side Coupled Drift Tube Linac (SCDTL) is an attractive 3 GHz accelerating structure composed of short DTL tanks coupled together by side coupling cavities, in the course of development of the 200 MeV proton linear accelerator for proton therapy planned for the Terapia Oncologica con Protoni (TOP) program of the Italian National Institute of Health (Istituto Superiore di Sanita, ISS). The TOP Linac will be used to boost to 70 MeV the 7 MeV proton beam from a linac injector. Our main concern is to investigate in detail the characteristics of the structure in terms of RF properties of the accelerating mode, like longitudinal and transverse shunt impedance and quality factor, and of the other modes that cause the origin of the tank dispersion curve, in order to stabilize the behaviour under operating conditions. Calculations performed with the computer three-dimensional (3D) codes MAFIA and SOPRANO on the smallest unit of the system (a single DTL tank without coupling cavities) and experimental measurements m...

Linac4, a New Injector for the CERN PS Booster

CERN Document Server

Garoby, R; Gerigk, F; Hanke, K; Lombardi, A; Pasini, M; Rossi, C; Sargsyan, E; Vretenar, M

2006-01-01

The first bottle-neck towards higher beam brightness in the LHC injector chain is due to space charge induced tune spread at injection into the CERN PS Booster (PSB). A new injector called Linac4 is proposed to remove this limitation. Using RF cavities at 352 and 704 MHz, it will replace the present 50 MeV proton Linac2, and deliver a 160 MeV, 40 mA H- beam. The higher injection energy will reduce space charge effects by a factor of 2, and charge exchange will drastically reduce the beam losses at injection. Operation will be simplified and the beam brightness required for the LHC ultimate luminosity should be obtained at PS ejection. Moreover, for the needs of non-LHC physics experiments like ISOLDE, the number of protons per pulse from the PSB will increase by a significant factor. This new linac constitutes an essential component of any of the envisaged LHC upgrade scenarios. It is also designed to become the low energy part of a future 3.5 GeV, multi-megawatt superconducting linac (SPL). The present desig...

Status of RF system for the JAERI energy-recovery linac FEL

International Nuclear Information System (INIS)

Sawamura, Masaru; Nagai, Ryoji

2006-01-01

The two types of the RF sources are used for the JAERI ERL-FEL. One is an all-solid state amplifier and the other is an inductive output tube (IOT). There are advantages of little failure and wide bandwidth for the all-solid state amplifier, low cost and high efficiency for IOT. The property of low cost with the IOT is suitable for a large machine like an energy recovery linac (ERL)

High-brightness rf linear accelerators

International Nuclear Information System (INIS)

Jameson, R.A.

1986-01-01

The issue of high brightness and its ramifications in linacs driven by radio-frequency fields is discussed. A history of the RF linacs is reviewed briefly. Some current applications are then examined that are driving progress in RF linacs. The physics affecting the brightness of RF linacs is then discussed, followed by the economic feasibility of higher brightness machines

RF Plasma modeling of the Linac4 H− ion source

CERN Document Server

Mattei, S; Hatayama, A; Lettry, J; Kawamura, Y; Yasumoto, M; Schmitzer, C

2013-01-01

This study focuses on the modelling of the ICP RF-plasma in the Linac4 H− ion source currently being constructed at CERN. A self-consistent model of the plasma dynamics with the RF electromagnetic field has been developed by a PIC-MCC method. In this paper, the model is applied to the analysis of a low density plasma discharge initiation, with particular interest on the effect of the external magnetic field on the plasma properties, such as wall loss, electron density and electron energy. The use of a multi-cusp magnetic field effectively limits the wall losses, particularly in the radial direction. Preliminary results however indicate that a reduced heating efficiency results in such a configuration. The effect is possibly due to trapping of electrons in the multi-cusp magnetic field, preventing their continuous acceleration in the azimuthal direction.

Matching the laser generated p bunch into a crossbar-H drift tube linac

Science.gov (United States)

Almomani, A.; Droba, M.; Ratzinger, U.; Hofmann, I.

2012-05-01

Proton bunches with energies up to 30 MeV have been measured at the PHELIX laser. Because of the laser-plasma interactions at a power density of about 4×1019W/cm2, a total yield of 1.5×1013protons was produced. For the reference energy of 10 MeV, the yield within ±0.5MeV was exceeding 1010protons. The important topic for a further acceleration of the laser generated bunch is the matching into the acceptance of an rf accelerator stage. With respect to the high space charge forces and the transit energy range, only drift tube linacs seem adequate for this purpose. A crossbar H-type (CH) cavity was chosen as the linac structure. Optimum emittance values for the linac injection are compared with the available laser generated beam parameters. Options for beam matching into a CH structure by a pulsed magnetic solenoid and by using the simulation codes LASIN and LORASR are presented.

Preliminary design of high-power wave-guide/transmission system for multimegawatt CW requirements of 100 MeV proton Linac

International Nuclear Information System (INIS)

Shrivastava, Purushottam; Wanmode, Y.D.; Hannurkar, P.R.

2002-01-01

Development of a 100 MeV CW proton Linac has been planned at CAT. This Linac will be needing CW rf power in the frequency ranges of 350 MHz and 700 MHz for its RFQ and DTL/CCDTL/SFDTL structures respectively. The power to the accelerating structures will be produced by either 1 MW CW or 250 kW CW klystron/inductive output tubes (HOM IOTs). The power needed by respective feed points in the structure is max. 250 kW which will be powered by splitting the power from 1 MW klystron/klystrode into four channels by using a wave-guide system. In case of using 250 kW tubes the power to the structures will be provided directly from each tube. Two types of wave-guide transmission system have been considered, viz WR 2300 for 350 MHz rf needs and WR 1500 for 700 MHz rf needs. The typical wave-guide system has been designed using the 1 MW CW klystron followed by wave-guide filter, dual directional coupler, high-power circulator, three 3 dB magic TEE power dividers to split the main channel into four equal channels of 250 kW each. Each individual channel has dual directional couplers, flexible wave-guide sections and high power ceramic vacuum window. The circulator and each power divider is terminated into the isolated ports by high power CW loads. Out of the four channels three channels have phase shifters. Present paper describes the technological aspects and design specifications-considerations for these stringent requirements. (author)

Spallation Neutron Source High Power RF Installation and Commissioning Progress

CERN Document Server

McCarthy, Michael P; Bradley, Joseph T; Fuja, Ray E; Gurd, Pamela; Hardek, Thomas; Kang, Yoon W; Rees, Daniel; Roybal, William; Young, Karen A

2005-01-01

The Spallation Neutron Source (SNS) linac will provide a 1 GeV proton beam for injection into the accumulator ring. In the normal conducting (NC) section of this linac, the Radio Frequency Quadupole (RFQ) and six drift tube linac (DTL) tanks are powered by seven 2.5 MW, 402.5 MHz klystrons and the four coupled cavity linac (CCL) cavities are powered by four 5.0 MW, 805 MHz klystrons. Eighty-one 550 kW, 805 MHz klystrons each drive a single cavity in the superconducting (SC) section of the linac. The high power radio frequency (HPRF) equipment was specified and procured by LANL and tested before delivery to ensure a smooth transition from installation to commissioning. Installation of RF equipment to support klystron operation in the 350-meter long klystron gallery started in June 2002. The final klystron was set in place in September 2004. Presently, all RF stations have been installed and high power testing has been completed. This paper reviews the progression of the installation and testing of the HPRF Sys...

Drift Tube Linac Conditioning of Tank1

CERN Document Server

Shafqat, N; Toor, W A

2014-01-01

Tank1 of the Drift Tube Linac (DTL) of the Linac4 has been conditioned at the Linac4 tunnel. The tank was tuned for resonance at 352.2 MHz, and stable operation has been achieved with 725 µs long RF pulses at a repetition rate of 1 Hz. The maximum RF level that has been reached is 810 kW with a pulse width of 600 µs. Since this was the first RF structure exclusively conditioned in the Linac4 tunnel with the operation and control software of Linac4, some related issues and limitations had to be taken into account.

High order modes in Project-X linac

Energy Technology Data Exchange (ETDEWEB)

Sukhanov, A., E-mail: ais@fnal.gov; Lunin, A.; Yakovlev, V.; Awida, M.; Champion, M.; Ginsburg, C.; Gonin, I.; Grimm, C.; Khabiboulline, T.; Nicol, T.; Orlov, Yu.; Saini, A.; Sergatskov, D.; Solyak, N.; Vostrikov, A.

2014-01-11

Project-X, a multi-MW proton source, is now under development at Fermilab. In this paper we present study of high order modes (HOM) excited in continues-wave (CW) superconducting linac of Project-X. We investigate effects of cryogenic losses caused by HOMs and influence of HOMs on beam dynamics. We find that these effects are small. We conclude that HOM couplers/dampers are not needed in the Project-X SC RF cavities.

Design and rf tuning of the KEK 40 MeV proton linear accelerator

International Nuclear Information System (INIS)

Kato, Takao.

1986-09-01

An Alvarez linac was designed and constructed on the basis of a model linac study to increase the output energy from 20 to 40 MeV. The linac was tuned by frequency tuners and post couplers. Stabilization of the field was achieved and a variation within ± 0.7 % of the accelerating field was obtained. An equivalent circuit analysis which can numerically solve loop equations, including stem and post currents in addition to tank current, can explain the rf characteristics of a postcoupled structure. (author)

Acceleration characteristics of the injector Linacs for the Hyogo Hadrontherapy Center

International Nuclear Information System (INIS)

Inoue, J.; Sawada, K.; Sakata, T.

2000-01-01

Hyogo Hadrontherapy center in Harima Science Garden City is a cancer therapy facility with proton, helium and carbon beams. The beams are supplied by a synchrotron, which has manufactured by Mitsubishi Electric Corporation, with RF 1inacs as an injector, which has manufactured by Sumitomo Heavy Industries Ltd.(SHI). The injector consists of the identical ECR ion sources, a RFQ linac, and an Alvarez linac, which are connected by beam transport systems including vacuum systems, and some kinds of beam monitoring equipments. The results accomplished for the beam conditioning are described in this paper. (author)

Alignment and Field Error Tolerance in Linac4

CERN Document Server

Bellodi, G; Garcia Tudela, M; Hein, L; Lallement, J B; Lanzone, S; Lombardi, A M; Posocco, P; Sargsyan, E

2011-01-01

LINAC4 [1] is a linear accelerator for negative Hydrogen ions (H−), which will replace the 50 MeV proton LINAC (LINAC2) as linear injector for the CERN accelerators. The higher output energy (160 MeV) together with charge-exchange injection will allow increasing beam intensity in the following machines. LINAC4 is about 80 m long, normal-conducting, and will be housed in a tunnel 12 m below ground on the CERN Meyrin site. The location has been chosen to allow using LINAC4 as the first stage of acceleration for a Multi-MegaWatt superconducting LINAC (SPL [2]). A 60 m long transfer line brings the beam towards the present LINAC2-to-PS Booster transfer line, which is joined at the position of BHZ20. The new transfer line consists of 17 new quadrupoles, an RF cavity and 4 bending magnets to adjust both the direction and the level for injection into the PS Booster. End-to-end beam dynamics simulations have been carried out in parallel with the codes PATH [3] and TRACEWIN[4]. Following the definition of the layout...

Imaging performance of a dedicated radiation transparent RF coil on a 1.0 Tesla inline MRI-linac.

Science.gov (United States)

Liney, Gary P; Dong, Bin; Weber, Ewald; Rai, Robba; Destruel, Aurelien; Garcia-Alvarez, Roberto; Manton, David; Jelen, Urszula; Zhang, Kevin; Barton, Michael; Keall, Paul J; Crozier, Stuart

2018-05-25

This work describes the first imaging studies on a 1.0 Tesla inline MRI-Linac using a dedicated transmit/receive RF body coil that has been designed to be completely radio transparent and provide optimum imaging performance over a large patient opening. Methods: A series of experiments was performed on the MRI-Linac to investigate the performance and imaging characteristics of a new dedicated volumetric RF coil: (1) numerical electromagnetic simulations were used to measure transmit efficiency in two patient positions; (2) image quality metrics of signal-to-noise ratio (SNR), ghosting and uniformity were assessed in a large diameter phantom with no radiation beam; (3) radiation induced effects were investigated in both the raw data (k-space) and image sequences acquired with simultaneous irradiation; (4) radiation dose was measured with and without image acquisition; (5) RF heating was studied using an MR-compatible fluoroptic thermometer and; (6) the in vivo image quality and versatility of the coil was demonstrated in normal healthy subjects for both supine and standing positions. Results: Daily phantom measurements demonstrated excellent imaging performance with stable SNR over a period of 3 months (42.6 ± 0.9). Simultaneous irradiation produced no statistical change in image quality (p>0.74) and no interference in raw data for a 20  20 cm radiation field. The coil was found to be efficient over large volumes and negligible RF heating was observed. Volunteer scans acquired in both supine and standing positions provided artefact free images with good anatomical visualisation. Conclusions: The first completely radio transparent RF coil for use on a 1.0 Tesla MRI-Linac has been described. There is no impact on either the imaging or dosimetry performance with a simultaneous radiation beam. The open design enables imaging and radiotherapy guidance in a variety of positons. . © 2018 Institute of Physics and Engineering in Medicine.

Medium Power 352 MHZ solid state pulsed RF amplifiers for the CERN LINAC4 Project

CERN Document Server

Broere, J; Gómez Martínez, Y; Rossi, M

2011-01-01

Economic, modular and highly linear pulsed RF amplifiers have recently been developed to be used for the three buncher cavities in the CERN Linac4. The amplifiers are water-cooled and can provide up to 33 kW pulsed RF Power, 1.5 ms pulse length and 50 Hz repetition rate. Furthermore a 60 kW unit is under construction to provide the required RF Power for the debuncher cavity. The concept is based on 1.2 kW RF power modules using the latest 6th generation LDMOS technology. For integration into the CERN control environment the amplifiers have an internal industrial controller, which will provide easy control and extended diagnostic functions. This paper describes the construction, performance, including linearity, phase stability and EMC compliance tests

Spatial and temporal beam profile monitor with nanosecond resolution for CERN's Linac4 and Superconducting Proton Linac

CERN Document Server

Hori, M

2008-01-01

The Linac4, now being developed at CERN, will provide 160-MeV H- beams of high intensity . Before this beam can be injected into the CERN Proton Synchrotron Booster or future Superconducting Proton Linac for further acceleration, some sequences of 500-ps-long micro-bunches must be removed from it, using a beam chopper. These bunches, if left in the beam, would fall outside the longitudinal acceptance of the accelerators and make them radioactive. We developed a monitor to measure the time structure and spatial profile of this chopped beam, with respective resolutions and . Its large active area and dynamic range also allows investigations of beam halos. The ion beam first struck a carbon foil, and secondary electrons emerging from the foil were accelerated by a series of parallel grid electrodes. These electrons struck a phosphor screen, and the resulting image of the scintillation light was guided to a thermoelectrically cooled, charge-coupled device camera. The time resolution was attained by applying high-...

Development of the low energy linac systems

International Nuclear Information System (INIS)

Cho, Yong Sub; Kwon, H. J.; Kim, Y. H.

2005-08-01

The project 'Development of the Low Energy Linac System' is aiming to develop the 20 MeV proton linac system. This consists of a 50 keV proton injector, a 3 MeV RFQ, and a 20 MeV DTL. We obtained the first beam signal after the 20 MeV linac. The high power switch installed in the ion source supplies the pulsed beam into the following LEBT. The pulse operation was successfully tested. The main role of the LEBT is to match the beam into the 3 MeV RFQ. The total length of the four-vane type RFQ is about 3.26m. For the field stabilization, we used the resonant coupling scheme and dipole stabilizer rods. An 1 MW klystron supplies the RF power into the RFQ. After tuning, the field deviation of the quadrupole mode is less than 2% of the design value and the dipole fraction is less than 5% of the operating mode. The following accelerating structure is DTL which accelerate 20 mA proton beams up to 20 MeV. It consists of 4 tanks and the length of each tank is less than 5 m. The lattice is FFDD type and the integrated fields of the quadrupole magnets are 1.75 T. The inner walls of the tanks are copper-plated by PR plating method. The thickness is 100m with the roughness of 0.3m. Each drift tube consists of 6 parts and assembled by e-beam welding. The tanks and drift tubes are aligned under the installation limit of 50m by using the laser-tracker. The tuning by the slug tuners and post couplers results in the field uniformity of 2% and field sensitivity of 100%/MHz. In order to detect the beam signal, we installed the Faraday cup after the RFQ or the DTL. For the RFQ, we observed the beam of 12 A under the forward RF power of 450 kW. The beam current after DTL is about 0.5 A when RF power of 150 kW was fed into each tank

Capacitive beam position monitors for the low-β beam of the Chinese ADS proton linac

Science.gov (United States)

Zhang, Yong; Wu, Jun-Xia; Zhu, Guang-Yu; Jia, Huan; Xue, Zong-Heng; Zheng, Hai; Xie, Hong-Ming; Kang, Xin-Cai; He, Yuan; Li, Lin; Denard, Jean Claude

2016-02-01

Beam Position Monitors (BPMs) for the low-β beam of the Chinese Accelerator Driven Subcritical system (CADS) Proton linac are of the capacitive pick-up type. They provide higher output signals than that of the inductive type. This paper will describe the design and tests of the capacitive BPM system for the low-β proton linac, including the pick-ups, the test bench and the read-out electronics. The tests done with an actual proton beam show a good agreement between the measurements and the simulations in the time domain. Supported by National Natural Science Foundation of China (11405240) and “Western Light” Talents Training Program of Chinese Academy of Sciences

Study on the Effects of the Modulator Output Ripple on the RF System of the KOMAC 100-MeV Proton Linear Accelerator

Energy Technology Data Exchange (ETDEWEB)

Kwon, Hyeok Jung; Kim, Han Sung; Seol, Kyung Tae; Jeong, Hae Sung; Kim, Sung Gu; Cho, Yong Sub [KAERI, Daejeon (Korea, Republic of)

2016-05-15

The high power system of the proton linear accelerator consists of accelerating cavities such as Radio Frequency Quadrupole (RFQ) and Drift Tube Linac (DTL), high power radio frequency (RF) systems such as klystrons, RF transmission lines and modulators as a klystron power supply. The modulator used at KOMAC adopted a high frequency switching technology using a 3-phase full bridge converter topology to produce 5.8 MW peak power at -105 kV with 9 % duty and produces a current ripple corresponding to the harmonics of the switching frequency. In this paper, the output ripple from the modulator is analyzed and its effects on the high power RF system are presented. The ripple current of the modulator was measured and analyzed. The higher harmonics of the switching frequency were measured and the dominant one was the third harmonic. And this ripple had an effect on the RF signal which was amplified through the klystron and delivered to the DTL. The dominant ripple component of the RF signal was also the third harmonics of the IGBT switching frequency of the modulator.

Beam dynamics and commissioning of low and medium energy H- beam at Linac4

CERN Document Server

Satri, Masoomeh Yarmohammadi; Lombardi, Alessandra; Lamehi-Rachti , Mohammad

The First step of the CERN Large Hadron Collider injectors upgrade (LIU) project is Linac4. It accelerates H- ions to 160 MeV in an 80 m long accelerator housed in a tunnel 12 m underground, presently under construction. It will replace the present 50 MeV proton Linac2 as injector of the proton accelerator complex to increase the LHC luminosity. It consists of a 45 keV RF volume source, a twosolenoid Low Energy Beam Transport (LEBT), a 352.2 MHz Radio Frequency Quadrupole (RFQ) accelerating the beam to 3 MeV, a Medium Energy Beam Transport (MEBT) line. The MEBT houses a fast chopper to selectively remove unwanted micro-bunches in the 352 MHz sequence and avoid losses at capture in the CERN PSB (1 MHz). After chopping, the beam acceleration continues by a 50 MeV Drift Tube Linac (DTL), a 100 MeV Cell-Coupled Drift Tube Linac and a Pi-Mode Structure bringing the beam to the final energy of 160 MeV. Linac4 has been commissioned with a temporary source up to 12 MeV. The beam commissioning stages of Linac4 in LEBT...

Beam Loss in Linacs

CERN Document Server

Plum, M.A.

2016-01-01

Beam loss is a critical issue in high-intensity accelerators, and much effort is expended during both the design and operation phases to minimize the loss and to keep it to manageable levels. As new accelerators become ever more powerful, beam loss becomes even more critical. Linacs for H- ion beams, such as the one at the Oak Ridge Spallation Neutron Source, have many more loss mechanisms compared to H+ (proton) linacs, such as the one being designed for the European Spallation Neutron Source. Interesting H- beam loss mechanisms include residual gas stripping, H+ capture and acceleration, field stripping, black-body radiation and the recently discovered intra-beam stripping mechanism. Beam halo formation, and ion source or RF turn on/off transients, are examples of beam loss mechanisms that are common for both H+ and H- accelerators. Machine protection systems play an important role in limiting the beam loss.

Pembuatan Dan Analisis Exciter Generator Rf Untuk Siklotron Proton Decy-13

OpenAIRE

Prajitno, Prajitno

2011-01-01

PEMBUATAN DAN ANALISIS EXCITER GENERATOR RF UNTUK SIKLOTRON PROTON DECY-13.Telah dilakukan analisis dan pembuatan exciter generator RF untuk siklotron proton 13MeV. Generator RFakan digunakan sebagai sumber tegangan pemercepat bolak-Balik siklotron DECY-13 rancangan PTAPBBATAN.Berdasarkan dokumen rancangan dasar yang telah dibuat siklotron Decy-13 akan menggunakanmedan magnet 1,275 Tesla, sehingga frekuensi generator RF bila menggunakan harmonik keempat adalah77,667 MHz. Salah satu teknik pem...

Matching the laser generated p bunch into a crossbar-H drift tube linac

Directory of Open Access Journals (Sweden)

A. Almomani

2012-05-01

Full Text Available Proton bunches with energies up to 30 MeV have been measured at the PHELIX laser. Because of the laser-plasma interactions at a power density of about 4×10^{19}  W/cm^{2}, a total yield of 1.5×10^{13}  protons was produced. For the reference energy of 10 MeV, the yield within ±0.5  MeV was exceeding 10^{10}  protons. The important topic for a further acceleration of the laser generated bunch is the matching into the acceptance of an rf accelerator stage. With respect to the high space charge forces and the transit energy range, only drift tube linacs seem adequate for this purpose. A crossbar H-type (CH cavity was chosen as the linac structure. Optimum emittance values for the linac injection are compared with the available laser generated beam parameters. Options for beam matching into a CH structure by a pulsed magnetic solenoid and by using the simulation codes LASIN and LORASR are presented.

Industrial RF Linac Experiences and Laboratory Interactions

CERN Document Server

Peiniger, M

2004-01-01

Since more than two decades ACCEL Instruments GmbH at Bergisch Gladbach (formerly Siemens/Interatom) is supplying the worldwide accelerator labs with key components like rf cavities and power couplers, s.c. magnets, insertion devices, vacuum chambers and x-ray beamline equipment. Starting with the design and production of turn key SRF accelerating modules in the late 80th, meanwhile ACCEL is engineering, manufacturing, on site commissioning and servicing complete accelerators with guaranteed beam performance. Today, with a staff of more than 100 physicists and engineers and about the same number of manufacturing specialists in our dedicated production facilities, ACCEL's know how and sales volume in this field has accumulated to more than 2000 man years and several hundred Mio €, respectively. Basis of our steady development is a cooperative partnership with the world leading research labs in the respective fields. As an example, for the supply of a turn key 100 MeV injector linac for the Swiss Ligh...

Study of influences of the first bunching cavity and injection conditions of rf SW linacs on particle transverse motions

International Nuclear Information System (INIS)

Lin Yuzheng; Tong Dechun; Sun Xiang; Xu Guanghua; Zhao Zhentang

1990-01-01

For both medical and radiographic standing wave linear accelerators, a small beam spot diameter is always pursued. In order to minimize the size and weight of the machine and reduce the power dissipation, rf focusing is preferred to the focusing solenoid coil. Therefore, it is important to study behaviours of beam transverse motions in the rf fields for the design of SW linacs. The research shows that the transverse motion behaviours of the electron beam in the compact linac is mainly determined by the rf field distribution on the first bunching cavity and injection conditions of the beam. In this paper, a beam envelope equation is presented,the proprties of the E z , E r , H θ field distributions of various first bunching cavities of both symmetric and asymmetric are studied, and then the rf electric force and rf magnetic force exerting on the beam with a different injection time are analysed. It is demonstrated that the asymmetric first bunching cavity with a small gradient of E z (z) field will provide a larger transverse emittance. And an asymmetric cavity with a larger front aperture and a small back aperture is favourable to make a smaller gradient of E z (z) field. For both symmetric and asymmetric first bunching cavity, by adopting an appropriate negative injection angle the envelopes of the beam are all decreased obviously, the optimum injection angle being always around -3 deg. The measured result of the beam spot of a 4 MeV SW linac shows that the mentioned simulation calculation of the radial dynamics above is in good agreement with the measured result

Study and optimization of a LINAC drift tube for high intensity proton acceleration; Etude et optimisation d'un LINAC a tubes de glissement pour acceleration de forts courants de protons en continu

Energy Technology Data Exchange (ETDEWEB)

Bernaudin, P.E

2002-09-01

High intensity proton accelerators lead to specific problems related to the need to limit beam losses. The problem is more acute in the low energy part (up to 20 MeV) where the beam transport is the most difficult. The drift tube linac (DTL) remains the reference structure for energies of a few MeV to a few dozens MeV despite the arising of some new cavity types. This thesis purpose is to design such a DTL for a high intensity proton accelerator. Until now, no such continuous wave cavity has ever been operated. To ensure the viability of such an accelerator, a short four cells prototype is designed, built and tested under nominal RF conditions. This prototype is fully representative of a complete machine except for its length. The design complexity comes from the combination of RF electromagnetism, thermal exchanges, mechanics, ultra-vacuum engineering and manufacturing constraints. More specifically, the electromagnets alignment is a primary factor, and reliability, despite being usually of secondary importance in particles accelerator science, is here a major concern considering potential industrial applications of this machine. The prototype design includes the cavity itself, but also quadrupole electromagnets whose feasibility is a limiting factor, considering the very small space available to them. Two different magnet types and associated drift tubes are studied and manufactured, to be tested in the prototype cavity. The experimental part is focused on mechanical and thermal aspects. The electromagnetic properties of the cavity are also checked. As a conclusion of this thesis, technical and conceptual improvements as suggested by the manufacturing and experimental phases are presented, to be implemented in a complete cavity. (author)

Mechanical features of a 700 MHz bridge-coupled drift tube linac

International Nuclear Information System (INIS)

Liska, D.; Smith, P.; Carlisle, L.; Larkin, T.; Lawrence, G.; Garnett, R.

1992-01-01

Modem linac designs for treating radioactive waste achieve high proton currents through funneling at low energy, typically around 20 MeV. The resulting switch to a high-frequency accelerating structure poses severe performance and fabrication difficulties below 100 MeV. Above 100 MeV, proven coupled-cavity linacs (CCLS) are available. However, at 20 MeV one must choose between a high-frequency drift-tube linac (DTL) or a coupled-cavity linac with very short cells. Potential radiation damage from the CW beam, excessive RF power losses, multipactoring, and fabricability all enter into this decision. At Los Alamos, we have developed designs for a bridge-coupled DTL (BCDTL) that, like a CCL, uses lattice focusing elements and bridge couplers, but that unlike a CCL, accelerates the beam in simple, short, large-aperture DTL modules with no internal quadrupole focusing. Thus, the BCDTL consumes less power than the CCL linac without beam performance and is simpler and cheaper to fabricate in the 20 to 100 MeV range

Conceptual Design of the Superconducting Proton Linac Short Cryo-module

CERN Document Server

Bourcey, N; Capatina, O; Azevedo, P; Montesinos, E; Parma, V; Renaglia, T; Vande Craen, A; Williams, L R; Weingarten, W; Rousselot, S; Duthil, P; Duchesne, P; Reynet, D; Dambre, P

2012-01-01

The Superconducting Proton Linac (SPL) is an R&amp;amp;D effort conducted by CERN in partnership with other international laboratories, aimed at developing key technologies for the construction of a multi-megawatt proton linac based on state-of-the-art Superconducting Radio Frequency technology, which would serve as a driver for new physics facilities such as neutrinos and radioactive ion beams. Amongst the main objectives of this effort, are the development of 704 MHz bulk niobium b=1 elliptical cavities, operating at 2 K and providing an accelerating field of 25 MV/m, and testing of a string of cavities integrated in a machine-type cryo-module. In an initial phase only four out of the eight cavities of an SPL cryo-module will be tested in a ½ length cryo-module developed for this purpose, and therefore called the Short Cryo-module. This paper presents the conceptual design of the SC, highlighting its innovative principles in terms of cavity supporting and alignment, and describes the integratio...

A new rf structure for intermediate-velocity particles

International Nuclear Information System (INIS)

Billen, J.H.; Krawczyk, F.L.; Wood, R.L.; Young, L.M.

1994-01-01

This paper describes an rf structure with high shunt impedance and good field stability for particle velocities o.1 ≤ β ≤ 0.5. Traditionally, the drift-tube linac (DTL) has been the structure of choice for this velocity range. The new structure, called a coupled-cavity drift-tube linac (CCDTL), combines features of the Alvarez DTL and the π-mode coupled-cavity linac (CCL). Each accelerating cavity is a two-cell, 0-mode DTL. The center-to-center distance between gaps is γλ. Adjacent accelerating cavities have oppositely directed electric fields, alternating in phase by 180 degrees. The chain of cavities operates in a π/2 structure mode so the coupling cavities are nominally unexcited. We will discuss 2-D and 3-D electromagnetic code calculations, and some initial measurements on a low-power model of a CCDTL. We will compare shunt impedance calculations for DTL, CCL, and CCDTL structures. The CCDTL has potential application for a wide range of ion linacs. For example, high-intensity proton linacs could use the CCDTL instead of a DTL up to an energy of about 200 MeV. Another example is a stand-alone, low-duty, low-current, very high gradient, proton, cancer therapy machine. The advantage for this application would be a saving in the cost of the machine because the linac would be short

HOM Coupler Optimisation for the Superconducting RF Cavities in ESS

CERN Document Server

Ainsworth, R; Calaga, R

2012-01-01

The European Spallation Source (ESS) will be the world’s most powerful next generation neutron source. It consists of a linear accelerator, target, and instruments for neutron experiments. The linac is designed to accelerate protons to a final energy of 2.5 GeV, with an average design beam power of 5 MW, for collision with a target used to produce a high neutron flux. A section of the linac will contain Superconducting RF (SCRF) cavities designed at 704 MHz. Beam induced HOMs in these cavities may drive the beam unstable and increase the cryogenic load, therefore HOM couplers are installed to provide sufficient damping. Previous studies have shown that these couplers are susceptible to multipacting, a resonant process which can absorb RF power and lead to heating effects. This paper will show how a coupler suffering from multipacting has been redesigned to limit this effect. Optimisation of the RF damping is also discussed.

Conceptual Design of the Low-Power and High-Power SPL A Superconducting H$^-$ Linac at CERN

CERN Document Server

Atieh, S; Aviles Santillana, I; Bartmann, W; Borburgh, J; Brunner, O; Calatroni, S; Capatina, O; Chambrillon, J; Ciapala, E; Eshraqi, M; Ferreira, L; Garoby, R; Goddard, B; Hessler, C; Hofle, W; Horvath-Mikulas, S; Junginger, T; Kozlova, E; Lebbos, E; Lettry, J; Liao, K; Lombardi, A M; Macpherson, A; Montesinos, E; Nisbet, D; Otto, T; Paoluzzi, M; Papke, K; Parma, V; Pillon, F; Posocco, P; Ramberger, S; Rossi, C; Schirm, K; Schuh, M; Scrivens, R; Torres Sanchez, R; Valuch, D; Valverde Alonso, N; Wegner, R; Weingarten, W; Weisz, S

2014-01-01

The potential for a superconducting proton linac (SPL) at CERN started to be seriously considered at the end of the 1990s. In the first conceptual design report (CDR), published in 2000 [1], most of the 352 MHz RF equipment from LEP was re-used in an 800 m long linac, and the proton beam energy was limited to 2.2 GeV. During the following years, the design was revisited and optimized to better match the needs of a high-power proton driver for neutrino physics. The result was a more compact (470 m long) accelerator capable of delivering 5 MW of beam power at 3.5 GeV, using state-of-the-art superconducting RF cavities at 704 MHz. It was described in a second CDR, published in 2006 [2]. Soon afterwards, when preparation for increasing the luminosity of the LHC by an order of magnitude beyond nominal became an important concern, a low-power SPL (LP-SPL) was studied as a key component in the renovation of the LHC injector complex. The combination of a 4 GeV LP-SPL injecting into a new 50 GeV synchrotron (PS2) was ...

High-power proton linac for transmuting the long-lived fission products in nuclear waste

Energy Technology Data Exchange (ETDEWEB)

Lawrence, G.P.

1991-01-01

High power proton linacs are being considered at Los Alamos as drivers for high-flux spallation neutron sources that can be used to transmute the troublesome long-lived fission products in defense nuclear waste. The transmutation scheme being studied provides a high flux (> 10{sup 16}/cm{sup 2}{minus}s) of thermal neutrons, which efficiently converts fission products to stable or short-lived isotopes. A medium-energy proton linac with an average beam power of about 110 MW can burn the accumulated Tc99 and I129 inventory at the DOE's Hanford Site within 30 years. Preliminary concepts for this machine are described. 3 refs., 5 figs., 2 tabs.

Linac 1, inner structure

CERN Multimedia

1968-01-01

This photo shows the inner structure of Linac 1. As injector to the PS, and later to the Booster, Linac 1 accelerated protons to 50 MeV, but it has also accelerated heavier ions. Fitted with a 520 keV RFQ pre-injector (instead of the original Cockcroft-Walton generator), it delivered protons and heavy ions to LEAR, from 1982 to 1992. After 33 years of faithful service, Linac 1 was dismantled in 1992 to make room for Linac 3 (Pb ions).

Development of a commissioning plan for the APT linac

International Nuclear Information System (INIS)

Funk, L.W.; Crandall, K.R.; Gilpatrick, J.D.; Gray, E.R.; Regan, A.H.; Rohlev, A.; Rybarcyk, L.J.; Wangler, T.P.

1998-01-01

The Accelerator Production of Tritium (APT) facility is based on a linac which incorporates both normal-conducting and superconducting RF technology and accelerates a 100-mA cw proton beam to an energy of 1,030 MeV or higher, depending on the desired production rate. Commissioning plans to achieve full power operation with minimum beam-induced activation of components have been evolving. This paper presents the main issues and the basic approaches that are now being discussed

Applications of High Intensity Proton Accelerators

Science.gov (United States)

Raja, Rajendran; Mishra, Shekhar

2010-06-01

Superconducting radiofrequency linac development at Fermilab / S. D. Holmes -- Rare muon decay experiments / Y. Kuno -- Rare kaon decays / D. Bryman -- Muon collider / R. B. Palmer -- Neutrino factories / S. Geer -- ADS and its potential / J.-P. Revol -- ADS history in the USA / R. L. Sheffield and E. J. Pitcher -- Accelerator driven transmutation of waste: high power accelerator for the European ADS demonstrator / J. L. Biarrotte and T. Junquera -- Myrrha, technology development for the realisation of ADS in EU: current status & prospects for realisation / R. Fernandez ... [et al.] -- High intensity proton beam production with cyclotrons / J. Grillenberger and M. Seidel -- FFAG for high intensity proton accelerator / Y. Mori -- Kaon yields for 2 to 8 GeV proton beams / K. K. Gudima, N. V. Mokhov and S. I. Striganov -- Pion yield studies for proton driver beams of 2-8 GeV kinetic energy for stopped muon and low-energy muon decay experiments / S. I. Striganov -- J-Parc accelerator status and future plans / H. Kobayashi -- Simulation and verification of DPA in materials / N. V. Mokhov, I. L. Rakhno and S. I. Striganov -- Performance and operational experience of the CNGS facility / E. Gschwendtner -- Particle physics enabled with super-conducting RF technology - summary of working group 1 / D. Jaffe and R. Tschirhart -- Proton beam requirements for a neutrino factory and muon collider / M. S. Zisman -- Proton bunching options / R. B. Palmer -- CW SRF H linac as a proton driver for muon colliders and neutrino factories / M. Popovic, C. M. Ankenbrandt and R. P. Johnson -- Rapid cycling synchrotron option for Project X / W. Chou -- Linac-based proton driver for a neutrino factory / R. Garoby ... [et al.] -- Pion production for neutrino factories and muon colliders / N. V. Mokhov ... [et al.] -- Proton bunch compression strategies / V. Lebedev -- Accelerator test facility for muon collider and neutrino factory R&D / V. Shiltsev -- The superconducting RF linac for muon

Long-term residual radioactivity in an intermediate-energy proton linac

Science.gov (United States)

Blaha, J.; La Torre, F. P.; Silari, M.; Vollaire, J.

2014-07-01

A new 160 MeV H- linear accelerator (LINAC4) is being installed at CERN to replace the present 50 MeV LINAC2 as proton injector of the PS Booster (PSB). During operation, the accelerator components will be activated by the beam itself and by the secondary radiation field. Detailed Monte Carlo simulations, for various beam energies and several decay times, were performed to predict the residual radioactivity in the main accelerator components and to estimate the residual dose rate inside the tunnel. The results of this study will facilitate future dismantling, handling and storage of the activated parts and consequently minimize the radiation dose to involved workers. The component activation was also compared with the exemption limits given in the current Swiss legislation and to the CERN design values, in order to make predictions for the future storage and disposal of radioactive waste. The airborne radioactivity induced by particles escaping the beam dump and the activation of the beam dump cooling water circuit were also quantified. The aim of this paper is to provide data of sufficiently general interest to be used for similar studies at other intermediate-energy proton accelerator facilities.

Long-term residual radioactivity in an intermediate-energy proton linac

International Nuclear Information System (INIS)

Blaha, J.; La Torre, F.P.; Silari, M.; Vollaire, J.

2014-01-01

A new 160 MeV H − linear accelerator (LINAC4) is being installed at CERN to replace the present 50 MeV LINAC2 as proton injector of the PS Booster (PSB). During operation, the accelerator components will be activated by the beam itself and by the secondary radiation field. Detailed Monte Carlo simulations, for various beam energies and several decay times, were performed to predict the residual radioactivity in the main accelerator components and to estimate the residual dose rate inside the tunnel. The results of this study will facilitate future dismantling, handling and storage of the activated parts and consequently minimize the radiation dose to involved workers. The component activation was also compared with the exemption limits given in the current Swiss legislation and to the CERN design values, in order to make predictions for the future storage and disposal of radioactive waste. The airborne radioactivity induced by particles escaping the beam dump and the activation of the beam dump cooling water circuit were also quantified. The aim of this paper is to provide data of sufficiently general interest to be used for similar studies at other intermediate-energy proton accelerator facilities

Development of L-band pillbox RF window

International Nuclear Information System (INIS)

Takeuchi, Y.; Fukuda, S.; Hisamatsu, H.; Saito, Y.; Takahashi, A.

1994-01-01

A pillbox RF output window was developed for the L-band pulsed klystron for the Japanese Hadron Project (JHP) 1-GeV proton linac. The window was designed to withstand a peak RF power of 6 MW, where the pulse width is 600 μsec and the repetition rate is 50 Hz. A high power model was fabricated using an alumina ceramic which has a low loss tangent of 2.5x10 -5 . A high power test was successfully performed up to a 113 kW RF average power with a 4 MW peak power, a 565 μsec pulse width and a 50 Hz repetition rate. By extrapolating the data of this high power test, the temperature rise of the ceramic is estimated low enough at the full RF power of 6 MW. Thus this RF window is expected to satisfy the specifications of the L-band Klystron. (author)

Conceptual design of the SPL II A high-power superconducting $H^-$ linac at CERN

CERN Document Server

Baylac, M; Benedico-Mora, E; Caspers, Friedhelm; Chel, S; Deconto, J M; Duperrier, R; Froidefond, E; Garoby, R; Hanke, K; Hill, C; Hori, M; Inigo-Golfin, J; Kahle, K; Kroyer, T; Küchler, D; Lallement, J B; Lindroos, M; Lombardi, A M; López Hernández, A; Magistris, M; Meinschad, T; Millich, Antonio; Noah-Messomo, E; Pagani, C; Palladino, V; Paoluzzi, M; Pasini, M; Pierini, P; Rossi, C; Royer, J P; Sanmartí, M; Sargsyan, E; Scrivens, R; Silari, M; Steiner, T; Tückmantel, Joachim; Uriot, D; Vretenar, M

2006-01-01

An analysis of the revised physics needs and recent progress in the technology of superconducting RF cavities have led to major changes in the speci cation and in the design for a Superconducting Proton Linac (SPL) at CERN. Compared with the rst conceptual design report (CERN 2000–012) the beam energy is almost doubled (3.5 GeV instead of 2.2 GeV), while the length of the linac is reduced by 40% and the repetition rate is reduced to 50 Hz. The basic beam power is at a level of 4–5MW and the approach chosen offers enough margins for upgrades. With this high beam power, the SPL can be the proton driver for an ISOL-type radioactive ion beam facility of the next generation (`EURISOL'), and for a neutrino facility based on superbeam C beta-beam or on muon decay in a storage ring (`neutrino factory'). The SPL can also replace the Linac2 and PS Booster in the low-energy part of the CERN proton accelerator complex, improving signi cantly the beam performance in terms of brightness and intensity for the bene t of al...

Mechanical features of a 700-MHz bridge-coupled drift-tube linac

International Nuclear Information System (INIS)

Liska, D.; Smith, P.; Carlisle, L.; Larkin, T.; Lawrence, G.; Garnett, R.

1992-01-01

Modern linac designs for treating radioactive waste achieve high proton currents through funneling at low energy, typically around 20 MeV. The resulting switch to a high-frequency accelerating structure poses severe performance and fabrication difficulties below 100 MeV. Above 100 MeV, proven coupled-cavity linacs (CCLs) are available. However, at 20 MeV one must choose between a high-frequency drift-tube linac (DTL) or a coupled-cavity linac with very short cells. Potential radiation damage from the CW beam, excessive RF power losses, multipactoring, and fabricability all enter into this decision. At Los Alamos, we have developed designs for a bridge-coupled DTL (BCDTL) that, like a CCL, uses lattice focusing elements and bridge couplers, but that unlike a CCL, accelerates the beam in simple, short, large-aperture DTL modules with no internal quadrupole focusing. Thus, the BCDTL consumes less power than the CCL linac without beam performance and is simpler and cheaper to fabricate in the 20 to 100 MeV range. (Author) ref., tab., 3 figs

Linacs for medical isotope production

International Nuclear Information System (INIS)

Pramudita, A.

2012-01-01

This paper reviews efforts on using high energy (25-30 MeV) and high power (10-20 kW) electron linacs and lower energy (7 MeV) proton linacs for medical radioisotope production. Using high energy x-rays from the electron linacs, PET (Positron Emission Tomography) radioisotopes are produced through photonuclear reactions such as 19 F(γ,n) 18 F, which also allow production of other PET radionuclides 11 C, 13 N, and 15 O. Other mostly used medical radionuclides 99m Tc can also be obtained by using the electron linacs, through photofission or photonuclear reactions. Proton linacs for PET have also been recently developed and the product has been available in the market since 2005. The linacs have been tested for 18 F production. As a proton accelerator, the target systems and nuclear reactions are similar to the ones used in PET cyclotrons. (author)

Characterization of Radiation Induced Current in RF coils of Linac-MR Systems

Science.gov (United States)

Burke, Benjamin Lester

by up to 60%. The SNR is improved in the images obtained concurrently with radiation if buildup is applied to the coil. The final part examined the effect of RIC on MR image quality. Imaging experiments were performed on the prototype linac-MR system and the RIC-induced signal-to-noise ratio (SNR) degradation of MR images was quantified. An image post-processing algorithm was proposed which removes some of the RIC-corrupted data from the MR images to recover some of the lost image SNR. The presence of RIC in MR RF coils leads to a loss of SNR which is directly related to the linac dose rate. The RIC related loss in SNR is likely to increase for future commercial systems that are likely to provide larger dose rate than the prototype system (250 cGy/min). Some of this SNR loss can be recovered through the use of a post-processing algorithm which removes the RIC artefact from the image k-space.

The RF power system for the SNS linac

International Nuclear Information System (INIS)

Tallerico, P.J.; Reass, W.A.

1998-01-01

The initial goal of the SNS project is to produce a 1 MW average beam of protons with short pulse lengths onto a neutron-producing target. The objective of the SNS RF system is to generate 117 MW peak of pulsed 805 MHz microwave power with an accelerated beam pulse length of 1.04 ms at a 60 Hz repetition rate. The power system must be upgradeable in peak power to deliver 2 MW average power to the neutron target. The RF system also requires about 3 MW peak of RF power at 402.5 MHz, but that system is not discussed here. The design challenge is to produce an RF system at minimum cost, that is very reliable and economical to operate. The combination of long pulses and high repetition rates make conventional solutions, such as the pulse transformer and transmission line method, very expensive. The klystron, with a modulating anode, and 1.5 MW of peak output power is the baseline RF amplifier, an 56 are required in the baseline design. The authors discuss four power system configurations that are the candidates for the design. The baseline design is a floating-deck modulating anode system. A second power system being investigated is the fast-pulsed power supply, that can be turned on and off with a rise time of under 0.1 ms. This could eliminate the need for a modulator, and drastically reduce the energy storage requirements. A third idea is to use a pulse transformer with a series IGBT switch and a bouncer circuit on the primary side, as was done for the TESLA modulator. A fourth method is to use a series IGBT switch at high voltage, and not use a pulse transformer. The authors discuss the advantages and problems of these four types of power systems, but they emphasize the first two

Development of a split coaxial RFQ for the JHP heavy ion linac

International Nuclear Information System (INIS)

Arai, Shigeaki.

1990-05-01

A split coaxial RFQ (SCRFQ) is being developed as the front-end structure of the heavy-ion linac chain planned in the Japanese Hadron Project (JHP). The features of the INS SCRFQ is that four modulated vanes are installed and that the whole cavity comprises short module cavities. The fundamental problems concerning to the rf and mechanical characteristics were clarified and solved through studies with a cold model. This model was then converted to an accelerating model working at 50 MHz. Acceleration tests using a proton beam showed that the linac had the designed performance. A 25.5-MHz prototype for a JHP machine is now under development. The cavity, 2.1 m in length and 0.9 m in diameter, has been built, and will accelerate ions with a charge-to-mass ratio greater than 1/30 from 1 keV/u to 45 keV/u. From low-power tests so far conducted, we have found that the cavity has good rf characteristics. (author)

Conceptual study of high power proton linac for accelerator driven subcritical nuclear power system

CERN Document Server

Yu Qi; Ouyang Hua Fu; Xu Tao Guang

2001-01-01

As a prior option of the next generation of energy source, the accelerator driven subcritical nuclear power system (ADS) can use efficiently the uranium and thorium resource, transmute the high-level long-lived radioactive wastes and raise nuclear safety. The ADS accelerator should provide the proton beam with tens megawatts. The superconducting linac is a good selection of ADS accelerator because of its high efficiency and low beam loss rate. The ADS accelerator presented by the consists of a 5 MeV radio-frequency quadrupole, a 100 MeV independently phased superconducting cavity linac and a 1 GeV elliptical superconducting cavity linac. The accelerating structures and main parameters are determined and the research and development plan is considered

Fabrication and tests and RF control of the superconducting resonators of the Saclay heavy ion LINAC

International Nuclear Information System (INIS)

Cauvin, B.; Coret, M.; Fouan, J.P.; Girard, J.; Girma, J.L.; Leconte, P.; Lussignol, Y.; Moreau, R.; Passerieux, J.P.; Ramstein, G.; Wartski, L.

1987-01-01

Two types of niobium superconducting resonators used in the Saclay linac are discussed. The outer cylinder and RF ports are identical for the two designs, but internal structures are different: full wave helix with three gaps behavior; or half wave with two gaps behavior. All cavities (34 full wave, 16 half) were tested for field and mounted in the machine cryostats. Cavity fabrication and performance are summarized. Vibration tests and Rf control are described. It is argued that helix resonators can overcome problems due to vibration. The very low lock out time percentage measured in an acceleration test with 21 cavities supports this confidence

Design study of a medical proton linac for neutron therapy

International Nuclear Information System (INIS)

Machida, S.; Raparia, D.

1988-01-01

This paper describes a design study which establishes the physical parameters of the low energy beam transport, radiofrequency quadrupole, and linac, using computer programs available at Fermilab. Beam dynamics studies verify that the desired beam parameters can be achieved. The machine described here meets the aforementioned requirements and can be built using existing technology. Also discussed are other technically feasible options which could be attractive to clinicians, though they would complicate the design of the machine and increase construction costs. One of these options would allow the machine to deliver 2.3 MeV protons to produce epithermal neutrons for treating brain tumors. A second option would provide 15 MeV protons for isotope production. 21 refs., 33 figs

The JAERI superconducting RF linac-based FELS and THEIR cryogenics

International Nuclear Information System (INIS)

Minehara, Eisuke J.

2003-01-01

In the 21st century, we need a powerful and efficient free-electron laser (FEL) for academic and industrial uses in almost all fields. In order to realize such a tunable, highly-efficient, high average power, high peak power and ultra-short pulse FEL, the JAERI FEL group and I have developed an industrial FEL driven by a compact, stand-alone and zero-boil off super-conducting rf linac with an energy-recovery geometry. Our discussions on the JAERI FEL and cryogenics will cover market-requirements for the industrial FELs, some answers from the JAERI compact, stand-alone and zero-boil off cryostat concept and operational experiences over these 9 years, our discovery of the new, highly-efficient, high-power, and ultra-short pulse lasing mode, and the energy-recovery geometry. (author)

TOP LINAC design; Progetto del TOP LINAC

Energy Technology Data Exchange (ETDEWEB)

Picardi, L; Ronsivalle, C; Vignati, A [ENEA, Centro Ricerche Frascati, Rome (Italy). Dip. Innovazione

1997-11-01

The report describes a linear accelerator for protons named TOP LINAC designed for the TOP (Terapia Oncologica con Protoni, Oncological Protontherapy) project launched by the Italian National Institute of Health (Istituto Superiore di Sanita`, ISS) to explore in collaboration with the biggest Oncological Hospital in Rome (Istituto Regina Elena, IRE) the potentialities of the therapy with accelerated protons and establish guide lines for the application of this new type of radiotherapy in comparison with the more traditional electron and x-rays radiotherapy. The concept of a compact accelerator for protontherapy applications bore within the Italian Hadrontherapy Collaboration (TERA Collaboration) with the aim to diffuse the protontherapy on the National territory. The ISS program plans to use the TOP linac proton beam also for production of PET (Positron Emission Tomography) radioisotopes and radiobiology studies. Official agreements are in course between ISS and ENEA which provides its experience in the industrial and medical accelerators for the design and the construction of the TOP linac. The accelerator that will be the first 3 GHz proton linac in the world, will be composed of a 428.3 MHz 7 Me V RFQ + DTL injector followed by a 7-65 Me V section of a 3 GHz SCDTL structure and a 65 - 200 Me V variable energy SCL 3 GHz structure. In particular the SCDTL section uses a highly innovative accelerating structure patented by ENEA. In this report the clinical and physical requests are discussed and a preliminary design of the whole machine is given.

Simulation studies of the LAMPF proton linac

International Nuclear Information System (INIS)

Garnett, R.W.; Gray, E.R.; Rybarcyk, L.J.; Wangler, T.P.

1995-01-01

The LAMPF accelerator consists of two 0.75-MeV injectors, one for H + and the other for H - , a separate low-energy beam transport (LEBT) line for each beam species, a 0.75 to 100-MeV drift-tube linac (DTL) operating at 201.25-MHz, a 100-MeV transition region (TR), and a 100 to 800-MeV side-coupled linac (SCL) operating at 805-MHz. Each LEBT line consists of a series of quadrupoles to transport and transversely match the beam. The LEBT also contains a prebuncher, a main buncher, and an electrostatic deflector. The deflector is used to limit the fraction of a macropulse which is seen by the beam diagnostics throughout the linac. The DTL consists of four rf tanks and uses singlet FODO transverse focusing. The focusing period is doubled in the last two tanks by placing a quadrupole only in every other drift-tube. Doublet FDO transverse focusing is used in the SCL. The TR consists of separate transport lines for the H + and H - beams. The pathlengths for the two beams differ, by introducing bends, so as to delay arrival of one beam relative to the other and thereby produce the desired macropulse time structure. Peak beam currents typically range from 12 to 18-mA for varying macropulse lengths which give an average beam current of 1-mA. The number of particles per bunch is of the order 10 8 . The work presented here is an extension of previous work. The authors have attempted to do a more complete simulation by including modeling of the LEBT. No measurements of the longitudinal structure of the beam, except phase-scans, are performed at LAMPF. The authors show that, based on simulation results, the primary causes of beam spill are inefficient longitudinal capture and the lack of longitudinal matching. Measurements to support these claims are not presently made at LAMPF. However, agreement between measurement and simulation for the transverse beam properties and transmissions serve to benchmark the simulations

Conceptual study of high power proton linac for accelerator driven subcritical nuclear power system

International Nuclear Information System (INIS)

Yu Qingchang; Ouyang Huafu; Xu Taoguang

2002-01-01

As a prior option of the next generation of energy source, the accelerator driven subcritical nuclear power system (ADS) can use efficiently the uranium and thorium resource, transmute the high-level long-lived radioactive wastes and raise nuclear safety. The ADS accelerator should provide the proton beam with tens megawatts. The superconducting linac is a good selection of ADS accelerator because of its high efficiency and low beam loss rate. The ADS accelerator presented by the authors consists of a 5 MeV radio-frequency quadrupole, a 100 MeV independently phased superconducting cavity linac and a 1 GeV elliptical superconducting cavity linac. The accelerating structures and main parameters are determined and the research and development plan is considered

X-band Linac for a 6 MeV dual-head radiation therapy gantry

Energy Technology Data Exchange (ETDEWEB)

Lee, Seung Hyun; Shin, Seung-Wook; Lee, Jongchul; Kim, Hui-Su [WCU Department of Energy Science, Suwon 440-746 (Korea, Republic of); Lee, Byeong-No; Lee, Byung-Chul [Radiation Instrumentation Research Division, Korea Atomic Energy Research Institute, Jeongeup 56212 (Korea, Republic of); Park, Hyung-dal; Song, Ki-back [Radiation Technology eXcellence (RTX), Daejeon 305-500 (Korea, Republic of); Song, Ho-seung; Mun, Sangchul; Ha, Donghyup [School of Information and Communication Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Chai, Jong-Seo, E-mail: jschai@skku.edu [School of Information and Communication Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

2017-04-21

We developed a design for a 6 MeV X-band linear accelerator for radiation therapy in a dual-head gantry layout. The dual-head gantry has two linacs that can be operated independently. Each X-band linac accelerates electron bunches using high-power RF and generates X-rays for radiation therapy. It requires a versatile RF system and pulse sequence to accomplish various radiation therapy procedures. The RF system consists of 9.3 GHz, 2 MW X-band magnetron and associated RF transmission components. A test linac was assembled and operated to characterize its RF performance without beam. This paper presents these results along with a description of the gantry linacs and their operational requirements.

Post-acceleration of laser driven protons with a compact high field linac

Science.gov (United States)

Sinigardi, Stefano; Londrillo, Pasquale; Rossi, Francesco; Turchetti, Giorgio; Bolton, Paul R.

2013-05-01

We present a start-to-end 3D numerical simulation of a hybrid scheme for the acceleration of protons. The scheme is based on a first stage laser acceleration, followed by a transport line with a solenoid or a multiplet of quadrupoles, and then a post-acceleration section in a compact linac. Our simulations show that from a laser accelerated proton bunch with energy selection at ~ 30MeV, it is possible to obtain a high quality monochromatic beam of 60MeV with intensity at the threshold of interest for medical use. In the present day experiments using solid targets, the TNSA mechanism describes accelerated bunches with an exponential energy spectrum up to a cut-off value typically below ~ 60MeV and wide angular distribution. At the cut-off energy, the number of protons to be collimated and post-accelerated in a hybrid scheme are still too low. We investigate laser-plasma acceleration to improve the quality and number of the injected protons at ~ 30MeV in order to assure efficient post-acceleration in the hybrid scheme. The results are obtained with 3D PIC simulations using a code where optical acceleration with over-dense targets, transport and post-acceleration in a linac can all be investigated in an integrated framework. The high intensity experiments at Nara are taken as a reference benchmarks for our virtual laboratory. If experimentally confirmed, a hybrid scheme could be the core of a medium sized infrastructure for medical research, capable of producing protons for therapy and x-rays for diagnosis, which complements the development of all optical systems.

Statistical simulations of machine errors for LINAC4

CERN Document Server

Baylac, M.; Froidefond, E.; Sargsyan, E.

2006-01-01

LINAC 4 is a normal conducting H- linac proposed at CERN to provide a higher proton flux to the CERN accelerator chain. It should replace the existing LINAC 2 as injector to the Proton Synchrotron Booster and can also operate in the future as the front end of the SPL, a 3.5 GeV Superconductingg Proton Linac. LINAC 4 consists of a Radio-Frequency Quadrupole, a chopper line, a Drift Tube Linac (DTL) and a Cell Coupled DTL all operating at 352 MHz and finally a Side Coupled Linac at 704 MHz. Beam dynamics was studied and optimized performing end-to-end simulations. This paper presents statistical simulations of machine errors which were performed in order to validate the proposed design.

X-band RF gun and linac for medical Compton scattering X-ray source

International Nuclear Information System (INIS)

Dobashi, Katsuhito; Uesaka, Mitsuru; Fukasawa, Atsushi; Sakamoto, Fumito; Ebina, Futaro; Ogino, Haruyuki; Urakawa, Junji; Higo, Toshiyasu; Akemoto, Mitsuo; Hayano, Hitoshi; Nakagawa, Keiichi

2004-01-01

Compton scattering hard X-ray source for 10-80 keV are under construction using the X-band (11.424 GHz) electron linear accelerator and YAG laser at Nuclear Engineering Research laboratory, University of Tokyo. This work is a part of the national project on the development of advanced compact medical accelerators in Japan. National Institute for Radiological Science is the host institute and U.Tokyo and KEK are working for the X-ray source. Main advantage is to produce tunable monochromatic hard (10-80 keV) X-rays with the intensities of 108-1010 photons/s (at several stages) and the table-top size. Second important aspect is to reduce noise radiation at a beam dump by adopting the deceleration of electrons after the Compton scattering. This realizes one beamline of a 3rd generation SR source at small facilities without heavy shielding. The final goal is that the linac and laser are installed on the moving gantry. We have designed the X-band (11.424 GHz) traveling-wave-type linac for the purpose. Numerical consideration by CAIN code and luminosity calculation are performed to estimate the X-ray yield. X-band thermionic-cathode RF-gun and RDS(Round Detuned Structure)-type X-band accelerating structure are applied to generate 50 MeV electron beam with 20 pC microbunches (104) for 1 microsecond RF macro-pulse. The X-ray yield by the electron beam and Q-switch Nd:YAG laser of 2 J/10 ns is 107 photons/RF-pulse (108 photons/sec at 10 pps). We design to adopt a technique of laser circulation to increase the X-ray yield up to 109 photons/pulse (1010 photons/s). 50 MW X-band klystron and compact modulator have been constructed and now under tuning. The construction of the whole system has started. X-ray generation and medical application will be performed in the early next year

X-band RF gun and linac for medical Compton scattering X-ray source

Science.gov (United States)

Dobashi, Katsuhito; Uesaka, Mitsuru; Fukasawa, Atsushi; Sakamoto, Fumito; Ebina, Futaro; Ogino, Haruyuki; Urakawa, Junji; Higo, Toshiyasu; Akemoto, Mitsuo; Hayano, Hitoshi; Nakagawa, Keiichi

2004-12-01

Compton scattering hard X-ray source for 10-80 keV are under construction using the X-band (11.424 GHz) electron linear accelerator and YAG laser at Nuclear Engineering Research laboratory, University of Tokyo. This work is a part of the national project on the development of advanced compact medical accelerators in Japan. National Institute for Radiological Science is the host institute and U.Tokyo and KEK are working for the X-ray source. Main advantage is to produce tunable monochromatic hard (10-80 keV) X-rays with the intensities of 108-1010 photons/s (at several stages) and the table-top size. Second important aspect is to reduce noise radiation at a beam dump by adopting the deceleration of electrons after the Compton scattering. This realizes one beamline of a 3rd generation SR source at small facilities without heavy shielding. The final goal is that the linac and laser are installed on the moving gantry. We have designed the X-band (11.424 GHz) traveling-wave-type linac for the purpose. Numerical consideration by CAIN code and luminosity calculation are performed to estimate the X-ray yield. X-band thermionic-cathode RF-gun and RDS(Round Detuned Structure)-type X-band accelerating structure are applied to generate 50 MeV electron beam with 20 pC microbunches (104) for 1 microsecond RF macro-pulse. The X-ray yield by the electron beam and Q-switch Nd:YAG laser of 2 J/10 ns is 107 photons/RF-pulse (108 photons/sec at 10 pps). We design to adopt a technique of laser circulation to increase the X-ray yield up to 109 photons/pulse (1010 photons/s). 50 MW X-band klystron and compact modulator have been constructed and now under tuning. The construction of the whole system has started. X-ray generation and medical application will be performed in the early next year.

Electron linacs

Energy Technology Data Exchange (ETDEWEB)

Loew, G A; Schriber, S O [ed.

1976-11-01

A study was made of the present status of the thousand or so electron linacs in the world, and future trends in the field. These machines were classified according to their use: medical, industrial, and nuclear physics. In the medical category, two types of electron linacs are discussed: the conventional ones which are used for x-ray and electron therapy, and those which may in the future be used for negative pion therapy. Industrial machines discussed include linacs for radiographic and other specialized applications. In the nuclear physics category, the status of conventional low- and medium-energy as well as high duty cycle linacs is reviewed. The question of how one might obtain a c-w, 1 GeV, 100..mu..A electron linac is raised, and various options using recirculation and stretchers are examined. In this connection, the status of rf superconductivity is summarized. A review is given of linacs for injectors into synchrotrons and e/sup +-/ storage rings, and recent work done to upgrade the only multi-GeV linac, namely SLAC, is described.

Electron linacs

International Nuclear Information System (INIS)

Loew, G.A.

1976-01-01

To study the present status of the thousand or so electron linacs in the world, and future trends in the field, we have classified these machines according to their use: medical, industrial, and nuclear physics. In the medical category, two types of electron linacs are discussed: the conventional ones which are used for X-ray and electron therapy, and those which may in the future be used for negative pion therapy. The section on industrial machines includes linacs for radiographic and other specialized applications. In the nuclear physics category, the status of conventional low- and medium-energy as well as high duty cycle linacs is reviewed. The question of how one might obtain a C.W., 1 GeV, 100 μA electron linac is raised and various options using recirculation and stretchers are examined. In this connection, the status of RF superconductivity is summarized. Following, there is a review of linacs for injectors into synchrotrons and e +- storage rings. The paper ends with a description of recent work done to upgrade the only multi-GeV linac, namely SLAC. (author)

Light ion linacs for medical applications

International Nuclear Information System (INIS)

Bradbury, J.N.; Knapp, E.A.; Nagle, D.E.

1975-01-01

Recent advances in linear accelerator technology point to the feasibility of designing and developing practical medical linacs for producing protons, neutrons, or π mesons for the radiation therapy of cancer. Additional uses of such linacs could include radioisotope production and charged particle radiography. For widespread utilization medical linacs must exhibit reasonable cost, compactness, reliability, and simplicity of operation. Possible extensions of current accelerator technology which might provide these characteristics are discussed in connection with linac design, fabrication techniques, materials, power sources, injectors, and particle collection and delivery systems. Parameters for a medical proton linac for producing pions are listed. (U.S.)

Prompt radiation, shielding and induced radioactivity in a high-power 160 MeV proton linac

Energy Technology Data Exchange (ETDEWEB)

Magistris, Matteo [CERN, CH-1211 Geneva 23 (Switzerland)]. E-mail: matteo.magistris@cern.ch; Silari, Marco [CERN, CH-1211 Geneva 23 (Switzerland)

2006-06-23

CERN is designing a 160 MeV proton linear accelerator, both for a future intensity upgrade of the LHC and as a possible first stage of a 2.2 GeV superconducting proton linac. A first estimate of the required shielding was obtained by means of a simple analytical model. The source terms and the attenuation lengths used in the present study were calculated with the Monte Carlo cascade code FLUKA. Detailed FLUKA simulations were performed to investigate the contribution of neutron skyshine and backscattering to the expected dose rate in the areas around the linac tunnel. An estimate of the induced radioactivity in the magnets, vacuum chamber, the cooling system and the concrete shield was performed. A preliminary thermal study of the beam dump is also discussed.

Design study of an S-band RF cavity of a dual-energy electron LINAC for the CIS

Science.gov (United States)

Lee, Byeong-No; Park, Hyungdal; Song, Ki-baek; Li, Yonggui; Lee, Byung Cheol; Cha, Sung-su; Lee, Jong-Chul; Shin, Seung-Wook; Chai, Jong-seo

2014-01-01

The design of a resonance frequency (RF) cavity for the dual-energy S-band electron linear accelerator (LINAC) has been carried out for the cargo inspection system (CIS). This Standing-wave-type RF cavity is operated at a frequency under the 2856-MHz resonance frequency and generates electron beams of 9 MeV (high mode) and 6 MeV (low mode). The electrons are accelerated from the initial energy of the electron gun to the target energy (9 or 6 MeV) inside the RF cavity by using the RF power transmitted from a 5.5-MW-class klystron. Then, electron beams with a 1-kW average power (both high mode and low mode) bombard an X-ray target a 2-mm spot size. The proposed accelerating gradient was 13 MV/m, and the designed Q value was about 7100. On going research on 15-MeV non-destructive inspections for military or other applications is presented.

Linac4 Low Energy Beam Measurements with Negative Hydrogen

CERN Document Server

Scrivens, R; Crettiez, O; Dimov, V; Gerard, D; Granemann Souza, E; Guida, R; Hansen, J; Lallement, J B; Lettry, J; Lombardi, A; Midttun, O; Pasquino, C; Raich, U; Riffaud, B; Roncarolo, F; Valerio-Lizarraga, C A; Wallner, J; Yarmohammadi Satri, M; Zickler, T

2014-01-01

Linac4, a 160 MeV normal-conducting H- linear accelerator, is the first step in the upgrade of the beam intensity available from the LHC proton injectors at CERN. The Linac4 Low Energy Beam Transport (LEBT) line from the pulsed 2 MHz RF driven ion source, to the 352 MHz RFQ has been built and installed at a test stand, and has been used to transport and match to the RFQ a pulsed 14 mA H- beam at 45 keV. A temporary slit-and-grid emittance measurement system has been put in place to characterize the beam delivered to the RFQ. In this paper a description of the LEBT and its beam diagnostics is given, and the results of beam emittance measurements and beam transmission measurements through the RFQ are compared with the expectation from simulations.

A development of BPM for P-LINAC at FAIR

Energy Technology Data Exchange (ETDEWEB)

Almalki, Mohammed; Kester, Oliver; Forck, Peter; Kaufmann, Wolfgang; Sieber, Thomas; Kowina, Piotr; Vinzenz, Wolfgang; Krueger, Christoph [GSI, Darmstadt (Germany); Simon, Claire [CEA/DSM/IRFU (France); Tinta, Dejan; Hrovatin, Rok; Lemut, Promoz [Instrumentation Technologies, Solkan (Slovenia)

2014-07-01

Four-fold button Beam Position Monitor (BPM) has been developed for the planned Proton LINAC at the FAIR facility. These monitors will be installed at 14 locations along the LINAC and four of them will be mounted only about 40 mm upstream of the CH cavities. A BPM prototype will be fabricated to evaluate the rf power at the BPM location as generated by cavity excitation as well as to test different options in the mechanical design. For the read-out electronics, the I/Q digital signal processing will be implemented to derive the transverse beam position and the beam phase. This contribution presents the status of the BPM development and focuses on the mechanical design and the optimization of the button pick-ups. The development progress of digital signal processing system is discussed as well.

Beam collimation and energy spectrum compression of laser-accelerated proton beams using solenoid field and RF cavity

Energy Technology Data Exchange (ETDEWEB)

Teng, J.; Gu, Y.Q., E-mail: tengjian@mail.ustc.edu.cn; Zhu, B.; Hong, W.; Zhao, Z.Q.; Zhou, W.M.; Cao, L.F.

2013-11-21

This paper presents a new method of laser produced proton beam collimation and spectrum compression using a combination of a solenoid field and a RF cavity. The solenoid collects laser-driven protons efficiently within an angle that is smaller than 12 degrees because it is mounted few millimeters from the target, and collimates protons with energies around 2.3 MeV. The collimated proton beam then passes through a RF cavity to allow compression of the spectrum. Particle-in-cell (PIC) simulations demonstrate the proton beam transport in the solenoid and RF electric fields. Excellent energy compression and collection efficiency of protons are presented. This method for proton beam optimization is suitable for high repetition-rate laser acceleration proton beams, which could be used as an injector for a conventional proton accelerator.

Beam collimation and energy spectrum compression of laser-accelerated proton beams using solenoid field and RF cavity

Science.gov (United States)

Teng, J.; Gu, Y. Q.; Zhu, B.; Hong, W.; Zhao, Z. Q.; Zhou, W. M.; Cao, L. F.

2013-11-01

This paper presents a new method of laser produced proton beam collimation and spectrum compression using a combination of a solenoid field and a RF cavity. The solenoid collects laser-driven protons efficiently within an angle that is smaller than 12 degrees because it is mounted few millimeters from the target, and collimates protons with energies around 2.3 MeV. The collimated proton beam then passes through a RF cavity to allow compression of the spectrum. Particle-in-cell (PIC) simulations demonstrate the proton beam transport in the solenoid and RF electric fields. Excellent energy compression and collection efficiency of protons are presented. This method for proton beam optimization is suitable for high repetition-rate laser acceleration proton beams, which could be used as an injector for a conventional proton accelerator.

Beam collimation and energy spectrum compression of laser-accelerated proton beams using solenoid field and RF cavity

International Nuclear Information System (INIS)

Teng, J.; Gu, Y.Q.; Zhu, B.; Hong, W.; Zhao, Z.Q.; Zhou, W.M.; Cao, L.F.

2013-01-01

This paper presents a new method of laser produced proton beam collimation and spectrum compression using a combination of a solenoid field and a RF cavity. The solenoid collects laser-driven protons efficiently within an angle that is smaller than 12 degrees because it is mounted few millimeters from the target, and collimates protons with energies around 2.3 MeV. The collimated proton beam then passes through a RF cavity to allow compression of the spectrum. Particle-in-cell (PIC) simulations demonstrate the proton beam transport in the solenoid and RF electric fields. Excellent energy compression and collection efficiency of protons are presented. This method for proton beam optimization is suitable for high repetition-rate laser acceleration proton beams, which could be used as an injector for a conventional proton accelerator

Dynamics of RF captured cooled proton beams

International Nuclear Information System (INIS)

Kells, W.; Mills, F.

1983-01-01

In the course of electron cooling experiments at the Electron Cooling Ring (ECR) at Fermilab, several peculiar features of the longitudinal phase space of cold protons (200 MeV) captured in RF buckets were observed. Here we present the experimental facts, present a simple theory, and summarize computer simulation results which support the theory and facts

A compact high-gradient 25 MeV 17 GHz RF linac for free-electron laser research

International Nuclear Information System (INIS)

Danly, B.G.; Chen, S.C.; Kreischer, K.E.

1995-01-01

A new compact high-gradient (60 MeV/m) high-frequency (17.136 GHz) RF linac is presently under construction by Haimson Research Corp. (HRC) for installation at the MIT Plasma Fusion Center in the High-Gradient Accelerator and High Power Microwave Laboratory. This accelerator will utilize an existing traveling-wave relativistic klystron (TWRK) which is now operation at MIT with 25 MW power, 67 dB gain, and 52% efficiency at 17.136 GHz

Beam forming system modernization at the MMF linac proton injector

CERN Document Server

Derbilov, V I; Nikulin, E S; Frolov, O T

2001-01-01

The isolation improvements of the beam forming system (BFS) of the MMF linac proton injector ion source are reported. The mean beam current and,accordingly, BFS electrode heating were increased when the MMF linac has began to operate regularly in long beam sessions with 50 Hz pulse repetition rate. That is why the BFS electrode high-voltage isolation that was made previously as two consequently and rigidly glued solid cylinder insulators has lost mechanical and electric durability. The substitution of large (160 mm) diameter cylinder insulator for four small diameter (20 mm) tubular rods has improved vacuum conditions in the space of beam forming and has allowed to operate without failures when beam currents being up to 250 mA and extraction and focusing voltage being up to 25 and 40 kV respectively. Moreover,the construction provides the opportunity of electrode axial move. The insulators are free from electrode thermal expansion mechanical efforts in a transverse direction.

Long-term residual radioactivity in an intermediate-energy proton linac

CERN Document Server

Blaha, J; Silari, M; Vollaire, J

2014-01-01

A new 160 MeV H−H− linear accelerator (LINAC4) is being installed at CERN to replace the present 50 MeV LINAC2 as proton injector of the PS Booster (PSB). During operation, the accelerator components will be activated by the beam itself and by the secondary radiation field. Detailed Monte Carlo simulations, for various beam energies and several decay times, were performed to predict the residual radioactivity in the main accelerator components and to estimate the residual dose rate inside the tunnel. The results of this study will facilitate future dismantling, handling and storage of the activated parts and consequently minimize the radiation dose to involved workers. The component activation was also compared with the exemption limits given in the current Swiss legislation and to the CERN design values, in order to make predictions for the future storage and disposal of radioactive waste. The airborne radioactivity induced by particles escaping the beam dump and the activation of the beam dump cooling w...

RF Power Requirements for PEFP SRF Cavity Test

International Nuclear Information System (INIS)

Kim, Han Sung; Seol, Kyung Tae; Kwon, Hyeok Jung; Cho, Yong Sub

2011-01-01

For the future extension of the PEFP (Proton Engineering Frontier Project) Proton linac, preliminary study on the SRF (superconducting radio-frequency) cavity is going on including a five-cell prototype cavity development to confirm the design and fabrication procedures and to check the RF and mechanical properties of a low-beta elliptical cavity. The main parameters of the cavity are like followings. - Frequency: 700 MHz - Operating mode: TM010 pi mode - Cavity type: Elliptical - Geometrical beta: 0.42 - Number of cells: 5 - Accelerating gradient: 8 MV/m - Epeak/Eacc: 3.71 - Bpeak/Eacc: 7.47 mT/(MV/m) - R/Q: 102.3 ohm - Epeak: 29.68 MV/m (1.21 Kilp.) - Geometrical factor: 121.68 ohm - Cavity wall thickness: 4.3 mm - Stiffening structure: Double ring - Effective length: 0.45 m For the test of the cavity at low temperature of 4.2 K, many subsystems are required such as a cryogenic system, RF system, vacuum system and radiation shielding. RF power required to generate accelerating field inside cavity depends on the RF coupling parameters of the power coupler and quality factor of the SRF cavity and the quality factor itself is affected by several factors such as operating temperature, external magnetic field level and surface condition. Therefore, these factors should be considered to estimate the required RF power for the SRF cavity test

Improved beam extraction for a negative hydrogen ion source for the LHC injector chain upgrade, Linac4

CERN Document Server

Midttun, Øystein; Scrivens, Richard

In the scope of an upgrade of the injector chain of CERN’s accelerator complex, a new linear accelerator, Linac4, is under construction. This accelerator will replace the existing 50 MeV proton linac, Linac2. By increasing the beam energy to 160 MeV, Linac4 makes it possible to double the brightness in the PSB, and ultimately increase the luminosity in the LHC. Linac4 will accelerate beams of negative hydrogen (H-) to be injected into the PSB by multi-turn, charge exchange injection. The ion source was initially based on the non-caesiated RF-volume source from DESY. However, the beam extraction from this source could not handle the 45 keV beam energy required by the RFQ. A new beam extraction system has therefore been designed, via IBSimu simulations [1], to extract and transport the H- ion beam respecting the Linac4 requirements. Key features of the extraction system is a tuneable puller voltage to adapt the extraction field to the ion and electron beam currents, and a magnetized Einzel lens to dump the co...

Status of the SNS superconducting linac and future plan

International Nuclear Information System (INIS)

Kim, Sang-Ho

2008-01-01

The use of superconducting radiofrequency (SRF) cavities in particle accelerator is becoming more widespread. Among the projects that make use of that technology is the Spallation Neutron Source, where H- ions are accelerated to about 1 GeV, mostly making use of niobium elliptical cavities. SNS generates neutrons by the spallation reaction with the accelerated short (about 700 ns) sub-bunches of protons, which will in turn allow probing structural and magnetic properties of new and existing materials. The SNS superconducting linac is the largest application of RF superconductivity to come on-line in the last decade and has been operating with beam for almost two years. As the first operational pulsed superconducting linac, many of the aspects of its performance were unknown and unpredictable. A lot of experiences and data have been gathered on the pulsed behavior of cavities and cryomodules at various repetition rates and at various temperatures during the commissioning of its components and beam operations. This experience is of great value in determining future optimizations of SNS as well in guiding in the design and operation of future pulsed superconducting linacs. The testing of the superconducting cavities, the operating experience with beam, the performance of the superconducting linac and the future plans will be presented.

SUPERCONDUCTING LINAC FOR THE SPALLATION NEUTRON SOURCE

International Nuclear Information System (INIS)

STOVALL, J.; NATH, S.

2000-01-01

The Spallation Neutron Source (SNS) linac is comprised of both normal and superconducting rf (SRF) accelerating structures. The SRF linac accelerates the beam from 186 to 1250 MeV through 117 elliptical, multi-cell niobium cavities. This paper describes the SRF linac architecture, physics design considerations, cavity commissioning, and the expected beam dynamics performance

Simulation of proton RF capture in the AGS Booster

International Nuclear Information System (INIS)

Khiari, F.Z.; Luccio, A.U.; Weng, W.T.

1988-01-01

RF capture of the proton beam in the AGS Booster has been simulated with the longitudinal phase-space tracking code ESME. Results show that a capture in excess of 95% can be achieved with multiturn injection of a chopped beam

Proton acceleration by RF TE{sub 11} mode in a cylindrical cavity

Energy Technology Data Exchange (ETDEWEB)

Sobajima, Masaaki; Yoshikawa, Kiyoshi; Ohnishi, Masami; Yamamoto, Yasushi; Masuda, Kai [Kyoto Univ., Uji (Japan). Inst. of Advanced Energy

1997-03-01

We found that protons are accelerated significantly by RF TE{sub 11} mode in a cylindrical cavity. In this method, protons get the perpendicular kinetic energy, so we thought it might be a compact accelerator, and studied the feasibility by numerical simulation. (author)

A magnetized Einzel lens electron dump for the Linac4 H− ion source

CERN Document Server

Midttun, O; Kronberger, M; Lettry, J; Pereira, H; Scrivens, R

2013-01-01

Linac4 is a 160 MeV linear accelerator which will inject negative hydrogen ions (H−) into CERN’s Proton Synchrotron Booster, a required upgrade to improve the beam brightness in the LHC injector chain. A volume production RF ion source, based on the design of the DESY RF source was implemented, but showed considerable electron dump ablation during operation at 45 keV beam energy. To reduce the electron beam power density in the dump, a magnetized Einzel lens is designed that reduces the beam energy to 10 keV before permanentmagnets dump the electrons on a tungsten surface. Presented in this paper are simulations of the design using IBSimu, the tunable range of parameters depending on the extracted H− and electron current, as well as details of the implementation, the choice of pulsed power converters and the electrode alignment system. In addition, simulations of proton extraction from this source will be shown.

first tank of Linac 1

CERN Multimedia

This was the first tank of the linear accelerator Linac1, the injection system for the Proton Synchrotron, It ran for 34 years (1958 - 1992). Protons entered at the far end and were accelerated between the copper drift tubes by an oscillating electromagnetic field. The field flipped 200 million times a second (200 MHz) so the protons spent 5 nanoseconds crossing a drift tube and a gap. Moving down the tank, the tubes and gaps had to get longer as the protons gained speed. The tank accelerated protons from 500 KeV to 10 MeV. Linac1 was also used to accelerate deutrons and alpha particles for the Intersecting Storage Rings and oxygen and sulpher ions for the Super Proton Synchrotron heavy ion programme.

Design and Development of RF Structures for Linac4

CERN Document Server

Vretenar, M; Gerigk, F; Pasini, M; Wegner, R

2006-01-01

Linac4 is a new 160 MeV H− linac proposed at CERN to replace the 50 MeV Linac2 as injector to the PS Booster, with the goal of doubling its brightness and intensity. The present design foresees after RFQ and chopping line a sequence of three accelerating structures: a Drift Tube Linac (DTL) from 3 to 40 MeV, a Cell-Coupled DTL (CCDTL) to 90 MeV and a Side Coupled Linac (SCL) up to the final energy. The DTL and CCDTL operate at 352 MHz, while in the SCL the frequency is doubled to 704 MHz. Although the injection in the PS Booster requires only a low duty cycle, the accelerating structures are designed to operate at the high duty cycle required by a possible future extension to a high-power linac driver for a neutrino facility. This paper presents the different accelerating structures, underlining the progress in the design of critical resonator elements, like post-couplers in the DTL, coupling slots in the CCDTL and bridge couplers for the SCL. Prototyping progress for the different structures is reported...

Discussion of superconducting and room-temperature high-intensity ion linacs

International Nuclear Information System (INIS)

Jameson, R.A.

1996-01-01

The point of view taken in this discussion is that the basic technology base exists in all essential respects for both superconducting or room-temperature rf linac accelerators and associated power and control systems, and thus a project can make a choice between these technologies on overall system considerations. These include performance, cost, availability, flexibility, and upgradability. Large high-intensity neutron source proposals involving light-ion rf linacs in three categories are reviewed in this context. The categories arc cw linacs to high (∼1 GeV) and low (∼40 MeV) output energy, and pulsed linacs to energy ∼1 GeV

LINAC5 - A Quasi-Alvarez Linac for BioLEIR

International Nuclear Information System (INIS)

Garland, J M; Lallement, J-B; Lombardi, A

2017-01-01

LINAC5 is a new linac proposed for the acceleration of light ions with Q/A = 1/3 to 1/4 for medical applications within the BioLEIR (Low Energy Ion Ring) design study at CERN. We propose a novel quasi-Alvarez drift-tube linac (DTL) accelerating structure design for LINAC5, which can reduce the length of a more conventional DTL structure, yet allows better beam focussing control and flexibility than the inter-digital H (IH) structures typically used for modern ion acceleration. We present the main sections of the linac with total length ∼12 m, including a 202 MHz radio frequency quadrupole (RFQ) a matching medium energy beam transport (MEBT) and a 405 MHz quasi-Alvarez accelerating section with an output energy of 4.2 MeV/u. Permanent magnet quadrupoles are proposed for use in the quasi-Alvarez structure to improve the compactness of the design and increase the efficiency. Lattice design considerations, multi-particle beam dynamics simulations and RFQ and radio frequency (RF) cavity designs are presented. (paper)

Linac4 low energy beam measurements with negative hydrogen ions

Energy Technology Data Exchange (ETDEWEB)

Scrivens, R., E-mail: richard.scrivens@cern.ch; Bellodi, G.; Crettiez, O.; Dimov, V.; Gerard, D.; Granemann Souza, E.; Guida, R.; Hansen, J.; Lallement, J.-B.; Lettry, J.; Lombardi, A.; Midttun, Ø.; Pasquino, C.; Raich, U.; Riffaud, B.; Roncarolo, F.; Valerio-Lizarraga, C. A.; Wallner, J.; Yarmohammadi Satri, M.; Zickler, T. [CERN, 1211 Geneva 23 (Switzerland)

2014-02-15

Linac4, a 160 MeV normal-conducting H{sup −} linear accelerator, is the first step in the upgrade of the beam intensity available from the LHC proton injectors at CERN. The Linac4 Low Energy Beam Transport (LEBT) line from the pulsed 2 MHz RF driven ion source, to the 352 MHz RFQ (Radiofrequency Quadrupole) has been built and installed at a test stand, and has been used to transport and match to the RFQ a pulsed 14 mA H{sup −} beam at 45 keV. A temporary slit-and-grid emittance measurement system has been put in place to characterize the beam delivered to the RFQ. In this paper a description of the LEBT and its beam diagnostics is given, and the results of beam emittance measurements and beam transmission measurements through the RFQ are compared with the expectation from simulations.

1-GeV Linac Upgrade Study at Fermilab

International Nuclear Information System (INIS)

Popovic, M.; Moretti, A.; Noble, R.; Schmidt, C.W.

1998-09-01

A linac injector for a new proton source complex at Fermilab is assumed to have a kinetic energy of 1 GeV. This linac would be sized to accelerate 100 mA of H - beam in a 200 microsecond pulse at a 15 Hz repetition rate. This would be adequate to produce ∼10 14 protons per pulse allowing for future improvements of the new proton source complex. An alternate proposal is to add 600 MeV of side coupled cavity linac at 805 MHz to the existing 400 MeV Linac. This addition may either be in a new location or use the present Booster tunnel. A discussion of these possibilities will be given

Mechanical Engineering of the Linac for the Spallation Neutron Source

International Nuclear Information System (INIS)

Bultman, N.K.; Chen, Z.; Collier, M.; Erickson, J.L.; Guthrie, A.; Hunter, W.T.; Ilg, T.; Meyer, R.K.; Snodgrass, N.L.

1999-01-01

The linac for the Spallation Neutron Source (SNS) Project will accelerate an average current of 1 mA of H - ions from 20 MeV to 1GeV for injection into an accumulator ring. The linac will be an intense source of H - ions and as such requires advanced design techniques to meet project technical goals as well as to minimize costs. The DTL, CCDTL and CCL are 466m long and operate at 805 MHz with a maximum H - input current of 28 mA and 7% rf duty factor. The Drift Tube Linac is a copper-plated steel structure using permanent magnetic quadrupoles. The Coupled-Cavity portions are brazed copper structures and use electromagnetic quads. RF losses in the copper are 80 MW, with total rf power supplied by 52 klystrons. Additionally, the linac is to be upgraded to the 2- and 4-MW beam power levels with no increase in duty factor. The authors give an overview of the linac mechanical engineering effort and discuss the special challenges and status of the effort

PASTA - An RF Phase and Amplitude Scan and Tuning Application

CERN Document Server

Galambos, J; Deibele, C; Henderson, S

2005-01-01

To assist the beam commissioning in the Spallation Neutron Source (SNS) linac, a general purpose RF tuning application has been written to help set RF phase and amplitude. It follows the signature matching procedure described in Ref.* The method involves varying an upstream Rf cavity amplitude and phase settings and comparing the measured downstream beam phase responses to model predictions. The model input for cavity phase and amplitude calibration and for the beam energy are varied to best match observations. This scheme has advantages over other RF tuning techniques of not requiring intercepting devices (e.g. Faraday Cups), and not being restricted to a small linear response regime near the design values. The application developed here is general and can be applied to different RF structure types in the SNS linac. Example applications in the SNS Drift Tube Linac (DTL) and Coupled Cavity Linac (CCL) structures will be shown.

Sparking limits, cavity loading, and beam breakup instability associated with high-current rf linacs

International Nuclear Information System (INIS)

Faehl, R.J.; Lemons, D.S.; Thode, L.E.

1982-01-01

The limitations on high-current rf linacs due to gap sparking, cavity loading, and the beam breakup instability are studied. It appears possible to achieve cavity accelerating gradients as high as 35 MV/m without sparking. Furthermore, a linear analysis, as well as self-consistent particle simulations of a multipulsed 10 kA beam, indicated that only a negligible small fraction of energy is radiated into nonfundamental cavity modes. Finally, the beam breakup instability is analyzed and found to be able to magnify initial radial perturbations by a factor of no more than about 20 during the beam transit time through a 1 GeV accelerator

TOP LINAC design

International Nuclear Information System (INIS)

Picardi, L.; Ronsivalle, C.; Vignati, A.

1997-11-01

The report describes a linear accelerator for protons named TOP LINAC designed for the TOP (Terapia Oncologica con Protoni, Oncological Protontherapy) project launched by the Italian National Institute of Health (Istituto Superiore di Sanita', ISS) to explore in collaboration with the biggest Oncological Hospital in Rome (Istituto Regina Elena, IRE) the potentialities of the therapy with accelerated protons and establish guide lines for the application of this new type of radiotherapy in comparison with the more traditional electron and x-rays radiotherapy. The concept of a compact accelerator for protontherapy applications bore within the Italian Hadrontherapy Collaboration (TERA Collaboration) with the aim to diffuse the protontherapy on the National territory. The ISS program plans to use the TOP linac proton beam also for production of PET (Positron Emission Tomography) radioisotopes and radiobiology studies. Official agreements are in course between ISS and ENEA which provides its experience in the industrial and medical accelerators for the design and the construction of the TOP linac. The accelerator that will be the first 3 GHz proton linac in the world, will be composed of a 428.3 MHz 7 Me V RFQ + DTL injector followed by a 7-65 Me V section of a 3 GHz SCDTL structure and a 65 - 200 Me V variable energy SCL 3 GHz structure. In particular the SCDTL section uses a highly innovative accelerating structure patented by ENEA. In this report the clinical and physical requests are discussed and a preliminary design of the whole machine is given

A SUPER-CONDUCTING LINAC DRIVER FOR THE HFBR.

Energy Technology Data Exchange (ETDEWEB)

Alessi, J.; Raparia, D.; Ruggiero, A.G.

2000-08-21

This paper reports on the feasibility study of a proton Super-Conducting Linac (SCL) as a driver for the High-Flux Breeder Reactor (HFBR) at Brookhaven National Laboratory (BNL). The Linac operates in Continuous Wave (CW) mode to produce an average 10 MW of beam power. The Linac beam energy is 1.0 GeV. The average proton beam intensity in exit is 10 mA.

Design and Calibration of an RF Actuator for Low-Level RF Systems

Science.gov (United States)

Geng, Zheqiao; Hong, Bo

2016-02-01

X-ray free electron laser (FEL) machines like the Linac Coherent Light Source (LCLS) at SLAC require high-quality electron beams to generate X-ray lasers for various experiments. Digital low-level RF (LLRF) systems are widely used to control the high-power RF klystrons to provide a highly stable RF field in accelerator structures for beam acceleration. Feedback and feedforward controllers are implemented in LLRF systems to stabilize or adjust the phase and amplitude of the RF field. To achieve the RF stability and the accuracy of the phase and amplitude adjustment, low-noise and highly linear RF actuators are required. Aiming for the upgrade of the S-band Linac at SLAC, an RF actuator is designed with an I/Qmodulator driven by two digital-to-analog converters (DAC) for the digital LLRF systems. A direct upconversion scheme is selected for RF actuation, and an on-line calibration algorithm is developed to compensate the RF reference leakage and the imbalance errors in the I/Q modulator, which may cause significant phase and amplitude actuation errors. This paper presents the requirements on the RF actuator, the design of the hardware, the calibration algorithm, and the implementation in firmware and software and the test results at LCLS.

Operational experience with the control scheme for IUAC linac booster

International Nuclear Information System (INIS)

Sahu, B.K.; Antony, J.; Mathuria, D.S.; Pandey, A.; Ghosh, S.; Mehta, R.; Rai, A.; Patra, P.; Choudhury, G.K.; Singh, K.; Ajith Kumar, B.P.; Kanjilal, D.; Roy, A.

2009-01-01

Accelerated beam from the first superconducting linear accelerator (linac) module of IUAC has been delivered to the user. The linac control scheme has worked successfully with the existing pelletron control scheme. Local RF control system consisting of Resonator controller and supporting RF modules are used for multipactoring conditioning, high power pulse conditioning and for the phase/amplitude locking of the superconducting resonators. Beam acceleration is done by adjusting the RF phase of each resonator with respect to master oscillator. The automation of control scheme is planned for smooth operation of linac with minimum human intervention. Python software support is added for writing automation routines in present control system software. An alternate tuning mechanism based on piezoelectric actuators has been successfully tested. (author)

Injection study of the Radiance 330 synchrotron with a 1.6 MeV RFQ linac

Science.gov (United States)

Wang, F.; Flanz, J.; Hamm, R.

2012-09-01

The ProTom Radiance 330 proton radiotherapy system provides the most advanced proton delivery capability to date. It supports true three-dimensional beam scanning with dynamic energy and intensity modulation. Most of the protons extracted from the synchrotron are used to treat the patient, which results in minimal neutron background in the treatment room. The patient dose rate depends upon the number of protons injected and the acceleration cycle time. Therefore, one can boost the dose rate by increasing the beam intensity at injection. Improvements to the existing tandem accelerator injector are already underway. However, an alternative way to attain higher intensity beam is to use an RFQ linac as an injector. To this end, a novel 1.6 MeV RFQ linac has been designed to specifically satisfy the small energy acceptance limits of the synchrotron. Simulations of the beam line optics and injection matching to the synchrotron have been performed using the computer codes PARMILA and TRACE-3D to determine if an additional bunching cavity is needed. Assessments of the space charge limit at the relatively low injection energy of 1.6 MeV and RF capture simulations have also been performed. Results of these studies are presented.

System design of a proton linac for the neutron science project at Japan Atomic Energy Research Institute

International Nuclear Information System (INIS)

Hasegawa, Kazuo; Mizumoto, Motoharu; Ouchi, Nobuo; Honda, Yoichiro; Ino, Hiroshi

1999-01-01

The Japan Atomic Energy Research Institute has been proposing the Neutron Science Project (NSP). The NSP requires pulse and CW proton beams with an energy of 1.5 GeV and an average beam power up to 8MW. This paper describes design concepts and parameters of the linac. A front end part of the linac, which consists of RFQ, DTL and SDTL sections, uses normal conducting structures and a high energy part uses superconducting (SC) structures. The linac has two injector lines for the pulse and the CW modes, respectively, and the two lines merge at 7 MeV. The total linac length is approximately 900 m and most of the part (>75%) is the superconducting section. An equipartitioning design, which is a new idea to suppress an emittance growth for high power linacs, has been taken for the DTL, the SDTL and the SC sections. Compared with the conventional constant phase advance design scheme, the equipartitioning design scheme is proved to be a good approach to suppress the longitudinal emittance growth. (author)

25th anniversary for Linac-2

CERN Multimedia

2003-01-01

On Friday, 3 October 2003, the Linac team celebrated a quarter century of successful operation of one of its linear accelerators: Linac-2, the proton workhorse of the CERN accelerator complex. Linac-2, CERN's linear proton accelerator, has now been running for 25 years - ample reason for a small celebration. About 30 members of the original team (10 of the initially more than 50 are still working at CERN), and other CERN personnel met on 3 October 2003. Linac-2 is the first link in the accelerator chain Linac-2 - PS Booster - PS - SPS and eventually LHC. Beams from Linac-2 are used after further acceleration in the CERN complex for SPS fixed target physics; for antiproton production for the Antiproton Decelerator (AD); for test beams in the East Experimental Hall and in the PS; for nuclear physics at ISOLDE; for LHC test beams and in the past for both ISR physics and Antiproton production (AA/AC) and test beams in LEAR. Linac-2 was built to obtain higher intensities and better stability than with ...

Development of a 352 MHz Cell-Coupled Drift Tube Linac Prototype

CERN Document Server

Cuvet, Y; Völlinger, C; Vretenar, M; Gerigk, F

2004-01-01

At linac energies above 40 MeV, alternative structures to the conventional Drift Tube Linac can be used to increase efficiency and to simplify construction and alignment. In the frame of the R&D activities for the CERN SPL and Linac4, a prototype of Cell-Coupled Drift Tube Linac (CCDTL) at 352 MHz has been designed and built. This particular CCDTL concept is intended to cover the energy range from 40 to 90 MeV and consists of modules of ~5 m length made of 3-gap DTL tanks linked by coupling cells. The focusing quadrupoles are placed between tanks, and are aligned independently from the RF structure. The CCDTL prototype consists of two half tanks connected by a coupling cell and requires an RF power of 120 kW to achieve the design gradient. RF tests will be made at low and high power, the latter up to a 20% duty cycle. This paper introduces the main features of this CCDTL design and describes the RF and mechanical design of the prototype.

RESONANCE CONTROL FOR THE COUPLED CAVITY LINAC AND DRIFT TUBE LINAC STRUCTURES OF THE SPALLATION NEUTRON SOURCE LINAC USING A CLOSED-LOOP WATER COOLING SYSTEM

International Nuclear Information System (INIS)

Bernardin, J.D.; Brown, R.L.

2001-01-01

The Spallation Neutron Source (SNS) is a facility being designed for scientific and industrial research and development. SNS will generate and use neutrons as a diagnostic tool for medical purposes, material science, etc. The neutrons will be produced by bombarding a heavy metal target with a high-energy beam of protons, generated and accelerated with a linear particle accelerator, or linac. The low energy end of the linac consists of two room temperature copper structures, the drift tube linac (DTL), and the coupled cavity linac (CCL). Both of these accelerating structures use large amounts of electrical energy to accelerate the protons to an energy of 185 MeV. Approximately 60-80% of the electrical energy is dissipated in the copper structure and must be removed. This is done using specifically designed water cooling passages within the linac's copper structure. Cooling water is supplied to these cooling passages by specially designed resonance control and water cooling systems

RF pulse compression in the NLC test accelerator at SLAC

International Nuclear Information System (INIS)

Lavine, T.L.

1995-01-01

At the Stanford Linear Accelerator Center (SLAC), the authors are designing a Next Linear Collider (NLC) with linacs powered by X-band klystrons with rf pulse compression. The design of the linac rf system is based on X-band prototypes which have been tested at high power, and on a systems-integration test - the Next Linear Collider Test Accelerator (NLCTA) - which is currently under construction at SLAC. This paper discusses some of the systems implications of rf pulse compression, and the use of pulse compression in the NLCTA, both for peak power multiplication and for controlling, by rf phase modulation, intra-pulse variations in the linac beam energy

Operational experience with the CERN hadron linacs

International Nuclear Information System (INIS)

Charmot, H.; Dutriat, C.; Hill, C.E.; Langbein, K.; Lombardi, A.M.; O'Neil, M.; Tanke, E.; Vretenar, M.

1996-01-01

The present CERN proton linac (Linac2) was commissioned in 1978 and since that date has been the primary source of protons to the CERN accelerator complex. During the past 18 years, the machine has had a very good reliability record in spite of the demands made upon it. Modifications have been made with the view of maintaining this reliability with reduced resources and new requirements from the users. Further demands will be made in the future for LHC operation. In 1994, a new linac for heavy ion production was put into service replacing the original CERN proton linac. As this machine was built within an international collaboration, operation had to take into account the novelty of the techniques used and the variety of equipment supplied by outside collaborators. Even so, the new machine has also had very good reliability. (author)

4-rod RFQ linac for ion implantation

Energy Technology Data Exchange (ETDEWEB)

Fujisawa, Hiroshi; Hamamoto, Nariaki; Inouchi, Yutaka [Nisshin Electric Co. Ltd., Kyoto (Japan)

1997-03-01

A 34 MHz 4-rod RFQ linac system has been upgraded in both its rf power efficiency and beam intensity. The linac is able to accelerate in cw operation 0.83 mA of a B{sup +} ion beam from 0.03 to 0.91 MeV with transmission of 61 %. The rf power fed to the RFQ is 29 kW. The unloaded Q-value of the RFQ has been improved approximately 61 % to 5400 by copper-plating stainless steel cooling pipes in the RFQ cavity. (author)

H- ion sources for CERN's Linac4

Science.gov (United States)

Lettry, J.; Aguglia, D.; Coutron, Y.; Chaudet, E.; Dallocchio, A.; Gil Flores, J.; Hansen, J.; Mahner, E.; Mathot, S.; Mattei, S.; Midttun, O.; Moyret, P.; Nisbet, D.; O'Neil, M.; Paoluzzi, M.; Pasquino, C.; Pereira, H.; Arias, J. Sanchez; Schmitzer, C.; Scrivens, R.; Steyaert, D.

2013-02-01

The specifications set to the Linac4 ion source are: H- ion pulses of 0.5 ms duration, 80 mA intensity and 45 keV energy within a normalized emittance of 0.25 mmmrad RMS at a repetition rate of 2 Hz. In 2010, during the commissioning of a prototype based on H- production from the plasma volume, it was observed that the powerful co-extracted electron beam inherent to this type of ion source could destroy its electron beam dump well before reaching nominal parameters. However, the same source was able to provide 80 mA of protons mixed with a small fraction of H2+ and H3+ molecular ions. The commissioning of the radio frequency quadrupole accelerator (RFQ), beam chopper and H- beam diagnostics of the Linac4 are scheduled for 2012 and its final installation in the underground building is to start in 2013. Therefore, a crash program was launched in 2010 and reviewed in 2011 aiming at keeping the original Linac4 schedule with the following deliverables: Design and production of a volume ion source prototype suitable for 20-30 mA H- and 80 mA proton pulses at 45 keV by mid-2012. This first prototype will be dedicated to the commissioning of the low energy components of the Linac4. Design and production of a second prototype suitable for 40-50 mA H- based on an external RF solenoid plasma heating and cesiated-surface production mechanism in 2013 and a third prototype based on BNL's Magnetron aiming at reliable 2 Hz and 80 mA H- operations in 2014. In order to ease the future maintenance and allow operation with Ion sources based on three different production principles, an ion source "front end" providing alignment features, pulsed gas injection, pumping units, beam tuning capabilities and pulsed bipolar high voltage acceleration was designed and is being produced. This paper describes the progress of the Linac4 ion source program, the design of the Front end and first ion source prototype. Preliminary results of the summer 2012 commissioning are presented. The outlook on

Minimum beam-energy spread of a high-current rf linac

International Nuclear Information System (INIS)

Chan, K.C.D.; Fraser, J.S.

1987-01-01

Energy spread is an important parameter of an electron linac and, usually, is determined by the time dependence of the external rf accelerating field. By using a combination of fundamental and higher harmonic frequencies, the accelerating field can be maintained approximately constant over a beam bunch with the resultant energy spread approximately zero. This technique is no longer adequate when the longitudinal wake field of the beam bunch is taken into account. The wake-field variation along the bunch length introduces an energy spread that cannot be exactly compensated for with the use of fundamental and higher harmonic frequencies. The achievable minimum energy spread including the wake-field effect is therefore limited. In this paper, we report the minimum energy spreads achievable using the fundamental and third-harmonic frequencies, calculated using a least-squares algorithm, for some typical structures in use at Los Alamos National Laboratory. The dependence of these results on bunch shape, bunch charge, and structure frequency is discussed. Also included are discussions of schemes for implementing the third-harmonic frequency and their effectiveness

Analysis of the LSC microbunching instability in MaRIE linac reference design

International Nuclear Information System (INIS)

Yampolsky, Nikolai

2016-01-01

In this report we estimate the effect of the microbunching instability in the MaRIE XFEL linac. The reference design for the linac is described in a separate report. The parameters of the L1, L2, and L3 linacs as well as BC1 and BC2 bunch compressors were the same as in the referenced report. The beam dynamics was assumed to be linear along the accelerator (which is a reasonable assumption for estimating the effect of the microbunching instability). The parameters of the bunch also match the parameters described in the referenced report. Additionally, it was assumed that the beam radius is equal to R = 100 m and does not change along linac. This assumption needs to be revisited at later studies. The beam dynamics during acceleration was accounted in the matrix formalism using a Matlab code. The input parameters for the linacs are: RF peak gradient, RF frequency, RF phase, linac length, and initial beam energy. The energy gain and the imposed chirp are calculated based on the RF parameters self-consistently. The bunch compressors are accounted in the matrix formalism as well. Each chicane is characterized by the beam energy and the R56 matrix element. It was confirmed that the linac and beam parameters described previously provide two-stage bunch compression with compression ratios of 10 and 20 resulting in the bunch of 3kA peak current.

A brief history of high power RF proton linear accelerators

International Nuclear Information System (INIS)

Browne, J.C.

1996-01-01

The first mention of linear acceleration was in a paper by G. Ising in 1924 in which he postulated the acceleration of positive ions induced by spark discharges which produced electric fields in gaps between a series of open-quotes drift tubesclose quotes. Ising apparently was not able to demonstrate his concept, most likely due to the limited state of electronic devices. Ising's work was followed by a seminal paper by R. Wideroe in 1928 in which he demonstrated the first linear accelerator. Wideroe was able to accelerate sodium or potassium ions to 50 keV of energy using drift tubes connected alternately to high frequency waves and to ground. Nuclear physics during this period was interested in accelerating protons, deuterons, electrons and alpha particles and not heavy ions like sodium or potassium. To accelerate the light ions required much higher frequencies than available at that time. So linear accelerators were not pursued heavily at that time. Research continued during the 1930s but the development of high frequency RF tubes for radar applications in World War 2 opened the potential for RF linear accelerators after the war. The Berkeley laboratory of E. 0. Lawrence under the leadership of Luis Alvarez developed a new linear proton accelerator concept that utilized drift tubes that required a full RF period to pass through as compared to the earlier concepts. This development resulted in the historic Berkeley 32 MeV proton linear accelerator which incorporated the open-quotes Alvarez drift tubeclose quotes as the basic acceleration scheme using surplus 200 MHz radar components

Progress in design of the SNS linac

International Nuclear Information System (INIS)

Hardekopf, R.

2001-01-01

The Spallation Neutron Source (SNS) is a six-laboratory collaboration to build an intense pulsed neutron facility at Oak Ridge, TN. The linac design has evolved from the conceptual design presented in 1997 in order to achieve higher initial performance and to incorporate desirable upgrade features. The linac is now designed to produce 2-MW beam power using a combination of radio-frequency quadrupole (RFQ) linac, drift-tube linac (DTL), coupled-cavity linac (CCL), and superconducting-RF (SRF) linac. Designs of each of these elements support he high peak intensity and high quality beam required for injection into the SNS accumulator ring. This paper will trace the evolution of the linac design and the progress made in the R and D program. (author)

RF pulse compression in the NLC test accelerator at SLAC

International Nuclear Information System (INIS)

Lavine, T.L.

1995-01-01

At the Stanford Linear Accelerator Center (SLAC), we are designing a Next Linear Collider (NLC) with linacs powered by X-band klystrons with rf pulse compression. The design of the linac rf system is based on X-band prototypes which have been tested at high power, and on a systems-integration test---the Next Linear Collider Test Accelerator (NLCTA)---which is currently under construction at SLAC. This paper discusses some of the systems implications of rf pulse compression, and the use of pulse compression in the NLCTA, both for peak power multiplication and for controlling, by rf phase modulation, intra-pulse variations in the linac beam energy. copyright 1995 American Institute of Physics

A hot-spare injector for the APS linac

International Nuclear Information System (INIS)

Lewellen, J. W.

1999-01-01

Last year a second-generation SSRL-type thermionic cathode rf gun was installed in the Advanced Photon Source (APS) linac. This gun (referred to as ''gun2'') has been successfully commissioned and now serves as the main injector for the APS linac, essentially replacing the Koontz-type DC gun. To help ensure injector availability, particularly with the advent of top-up mode operation at the APS, a second thermionic-cathode rf gun will be installed in the APS linac to act as a hot-spare beam source. The hot-spare installation includes several unique design features, including a deep-orbit Panofsky-style alpha magnet. Details of the hot-spare beamline design and projected performance are presented, along with some plans for future performance upgrades

Fault-tolerant superconducting linac design for a 5-MW neutron spallation source

International Nuclear Information System (INIS)

Swain, G.R.

1993-01-01

An 805-MHz superconducting linac is proposed which could accelerate protons from 0.1 to 2.0 GeV in less than 730 m for a peak surface field in the cavities of 17 MV/m. The linac would furnish 5 MW of beam for a neutron spallation source, plus up to 10 additional MW of beam for other purposes. The design uses 454 elliptical cavities arranged in twelve groups, identical cavities being used within each group. Characterization of elliptical cavities for betas from 0.44 to 0.94 and the steps of the design procedure are presented. The effective peak power fed by each rf coupler would be less than 100 kW for all of the cavities. 6.5 kW of power at 2 deg K would need to be extracted by the cryogenic system. Space charge was found to have a negligible effect on emittance growth. The design is such that one cavity per group could be inoperable, and the gradient in the remaining cavities could be increased to compensate. The longitudinal and transverse acceptances of the linac would not be significantly degraded under such fault conditions. A corresponding 402.5 MHz linac design is being developed

RF Phase Scan for Beam Energy Measurement of KOMAC DTL

Energy Technology Data Exchange (ETDEWEB)

Kim, Hansung; Kwon, Hyeokjung; Kim, Seonggu; Lee, Seokgeun; Cho, Yongsub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

The energy gain through the drift tube linac is a function of the synchronous phase, therefore, the output beam energy from DTL can be affected by the RF phase setting in low-level RF (LLRF) system. The DTL at Korea Multi-purpose Accelerator Complex (KOMAC) consists of 11 tanks and the RF phase setting in each tank should be matched for synchronous acceleration in successive tanks. That means a proper setting of RF phase in each DTL tank is critical for efficient and loss-free operation. The matching RF phase can be determined based on the output energy measurement from the DTL tank. The beam energy can be measured by several methods. For example, we can use a bending magnet to determine the beam energy because the higher momentum of beam means the less deflection angle in the fixed magnetic field. By measuring the range of proton beam through a material with known stopping power also can be utilized to determine the beam energy. We used a well-known time-of-flight method to determine the output beam energy from the DTL tank by measuring beam phase with a beam position monitor (BPM). Based on the energy measurement results, proper RF operating point could be obtained. We performed a RF phase scan to determine the output beam energy from KOMAC DTL by using a time-of-flight method and to set RF operating point precisely. The measured beam energy was compared with a beam dynamics simulation and showed a good agreement. RF phase setting is critical issue for the efficient operation of the proton accelerator, we have a plan to implement and integrate the RF phase measurement system into an accelerator control system for future need.

Accelerator study note: An attempt of 1 GeV linac

International Nuclear Information System (INIS)

Kato, Takao.

1987-01-01

A hypothetical 1 GeV linac is described, including its structure (which includes an ion source, radio frequency quadrupole linac, drift type linac, and coupled cavity linac), criteria for optimized design, cost optimization, frequency dependability of high frequency electric power loss, tuning during operation, the general rf system, computer codes and example calculations, beam dynamics simulation, and reduction of energy spread through the use of a debuncher

Finite Element Thermal Study of the Linac4 Plasma Generatora

CERN Document Server

Faircloth, D; Kuchler, D; Lettry, L; Scrivens, R; CERN. Geneva. BE Department

2010-01-01

The temperature distribution and heat flow at equilibrium of the plasma generator of the RF-powered non-cesiated Linac4 H- ion source have been studied with a finite element model. It is shown that the equilibrium temperatures obtained in the Linac4 nominal operation mode (100 kW RF power, 2 Hz, 0.4 ms pulse duration) are within material specifications except for the magnet cage, where a redesign may be necessary. To assess the upgrade of the Linac4 source for operation in the high-power operation mode of SPL, an extrapolation of the heat load towards 100 kW RF power, 50 Hz repetition rate and 0.4 ms pulse duration has been performed. The results indicate that a significant improvement of the source cooling is required to allow for operation in HP-SPL.

1 MW, 352.2 MHz, CW and Pulsed RF test stand

International Nuclear Information System (INIS)

Badapanda, M.K.; Tripathi, Akhilesh; Upadhyay, Rinki; Tyagi, Rajiv; Hannurkar, P.R.

2011-01-01

A 1 MW, 352.2 MHz, RF test stand based on Thales make TH 2089 klystron amplifier is being developed at Raja Ramanna Centre for Advanced Technology (RRCAT), Indore for characterization and qualification of RF components, cavities and related subsystems. Provision to vary RF power from 50 kW to 1 MW with adequate flexibility for testing wide range of HV components, RF components and cavities is incorporated in this test stand. The paper presents a brief detail of various power supplies like high voltage cathode bias power supply, modulating anode power supply, filament power supply, electromagnet power supplies and ion pump power supplies along with their interconnections for biasing TH 2089 klystron amplifier. A digital control and interlock system is being developed to realize proper sequence of operation of various power supplies and to monitor the status of crucial parameters in this test set up. This RF test stand will be a unique national facility, capable of providing both CW and pulse RF power for realizing reliable RF power sources for various projects including the development of high energy proton linac under ADSS program of the Department of Atomic Energy. (author)

High field electron linacs

International Nuclear Information System (INIS)

Le Duff, J.

1985-12-01

High field electron linacs are considered as potential candidates to provide very high energies beyond LEP. Since almost twenty years not much improvement has been made on linac technologies as they have been mostly kept at low and medium energies to be used as injectors for storage rings. Today, both their efficiency and their performances are being reconsidered, and for instance the pulse compression sheme developed at SLAC and introduced to upgrade the energy of that linac is a first step towards a new generation of linear accelerators. However this is not enough in terms of power consumption and more development is needed to improve both the efficiency of accelerating structures and the performances of RF power sources

CAS CERN Accelerator School: Cyclotrons, linacs and their applications. Proceedings

International Nuclear Information System (INIS)

Turner, S.

1996-01-01

These proceedings present the lectures given at the eighth specialized course organized by the CERN Accelerator School (CAS), the topic this time being 'Cyclotrons, Linacs and Their Applications'. Following an introductory lecture on linacs, the fundamental features of electron, ion and induction linacs are described together with their RF systems and particle sources. Cyclotrons are then introduced followed by details of their different types, their magnet and RF design, and their injection and extraction systems, with a glance towards exotic and possible future machines. Chapters are then presented on the use of linacs and cyclotrons for medical, fission, fusion and material applications, as well as for isotope production. Finally, descriptions of the design of a radioisotope facility, the matching of accelerators to their task and the computational tools used in their design are included. (orig.)

CAS CERN Accelerator School: Cyclotrons, linacs and their applications. Proceedings

Energy Technology Data Exchange (ETDEWEB)

Turner, S [ed.

1996-03-04

These proceedings present the lectures given at the eighth specialized course organized by the CERN Accelerator School (CAS), the topic this time being `Cyclotrons, Linacs and Their Applications`. Following an introductory lecture on linacs, the fundamental features of electron, ion and induction linacs are described together with their RF systems and particle sources. Cyclotrons are then introduced followed by details of their different types, their magnet and RF design, and their injection and extraction systems, with a glance towards exotic and possible future machines. Chapters are then presented on the use of linacs and cyclotrons for medical, fission, fusion and material applications, as well as for isotope production. Finally, descriptions of the design of a radioisotope facility, the matching of accelerators to their task and the computational tools used in their design are included. (orig.).

Superconducting linac booster for NSC Pelletron

International Nuclear Information System (INIS)

Roy, A.; Prakash, P.N.; Ajithkumar, B.P.; Ghosh, S.; Changrani, T.; Mehta, R.; Sarkar, A.; Muralidhar, S.; Dutt, R.N.; Kumar, M.; Shepard, K.W.; and others.

1996-01-01

The progress made in the heavy ion superconducting linac booster project for the Nuclear Science Centre Pelletron accelerator is overviewed. Prototypes of the accelerating structure have been fabricated at Argonne National Laboratory and undergone several diagnostic tests. In the first phase heavy ions up to mass 80 will be accelerated to energies above the Coulomb barrier and in the second phase the mass limit would be increased to 120. The subsystems of the project are the basic accelerating structures, the RF instrumentation and control, the cryogenic system and the beam optics. Preliminary designs for the buncher and linac cryostats have been made. Several prototypes of RF electronics and control modules have been fabricated and tested. (R.P.)

A 2--4 nm Linac Coherent Light Source (LCLS) using the SLAC linac

International Nuclear Information System (INIS)

Winick, H.; Bane, K.; Boyce, R.

1993-05-01

We describe the use of the SLAC linac to drive a unique, powerful. short wavelength Linac Coherent Light Source (LCLS). Operating as an FEL, lasing would be achieved in a single pass of a high peak current electron beam through a long undulator by self-amplified spontaneous emission (SASE). The main components are a high-brightness rf photocathode electron gun; pulse compressors; about 1/5 of the SLAC linac; and a long undulator with a FODO quadrupole focussing system. Using electrons below 8 GeV, the system would operate at wavelengths down to about 3 nm, producing ≥10 GW peak power in sub-ps pulses. At a 120 Hz rate the average power is ∼ 1 W

Spin-flipping a stored polarized proton beam with an rf dipole

International Nuclear Information System (INIS)

Blinov, B.B.; Derbenev, Ya.S.; Kageya, T.; Kantsyrev, D.Yu.; Krisch, A.D.; Morozov, V.S.; Sivers, D.W.; Wong, V.K.; Anferov, V.A.; Schwandt, P.; Przewoski, B. von

2000-01-01

Frequent polarization reversals, or spin-flips, of a stored polarized high-energy beam may greatly reduce systematic errors of spin asymmetry measurements in a scattering asymmetry experiment. We studied the spin-flipping of a 120 MeV horizontally-polarized proton beam stored in the IUCF Cooler Ring by ramping an rf-dipole magnet's frequency through an rf-induced depolarizing resonance in the presence of a nearly-full Siberian snake. After optimizing the frequency ramp parameters, we used multiple spin-flips to measure a spin-flip efficiency of 86.5±0.5%. The spin-flip efficiency was apparently limited by the rf-dipole's field strength. This result indicates that an efficient spin-flipping a stored polarized beam should be possible in high energy rings such as RHIC and HERA where Siberian snakes are certainly needed and only dipole rf-flipper-magnets are practical

Phase and amplitude stability of a pulsed RF system on the example of the CLIC drive beam LINAC

CERN Document Server

AUTHOR|(CDS)2132320; Prof. BANTEL, Michael

The CLIC drive beam accelerator consists of the Drive Beam Injector (DBI) and two Drive Beam Linacs (DBLs). The drive beam injector is composed of a thermionic electron source, 3 Sub Harmonic Bunchers (SHBs), a pre-buncher, and several acceleration structures. In the electron source the DC electron beam is produced from a thermionic cathode. The following buncher cavities group ("bunch") the electrons to be accelerated by RF later on. Each electron bunch has an energy of 140 keV, a length of 3 mm, and a charge qb = 8.4 nC. Afterwards the electrons are accelerated in the 1 GHz accelerating structures up to 50MeV. The pulsed Radio Frequency (RF) power for this acceleration is provided by 1 GHz, 20MW modulator-klystron units, one per acceleration structure. A klystron is an RF amplifier based on a linear-beam vacuum tube. The high voltage modulator supplies the acceleration voltage to this tube. A DC electron beam gets modulated with an input signal, the modulation enhances in a drift space, and finally the powe...

Radial focusing and energy compression of a laser-produced proton beam by a synchronous rf field

Directory of Open Access Journals (Sweden)

Masahiro Ikegami

2009-06-01

Full Text Available The dynamics of a MeV laser-produced proton beam affected by a radio frequency (rf electric field has been studied. The proton beam was emitted normal to the rear surface of a thin polyimide target irradiated with an ultrashort pulsed laser with a power density of 4×10^{18}  W/cm^{2}. The energy spread was compressed to less than 11% at the full width at half maximum (FWHM by an rf field. Focusing and defocusing effects of the transverse direction were also observed. These effects were analyzed and reproduced by Monte Carlo simulations. The simulation results show that the transversely focused protons had a broad continuous spectrum, while the peaks in the proton spectrum were defocused. Based on this new information, we propose that elimination of the continuous energy component of laser-produced protons is possible by utilizing a focal length difference between the continuous spectral protons and the protons included in the spectral peak.

University of Washington superconducting booster linac

International Nuclear Information System (INIS)

Storm, D.W.; Amsbaugh, J.F.; Cramer, J.G.; Swanson, H.E.; Trainor, T.A.; Vandenbosch, R.; Weitkamp, W.G.; Will, D.I.

1985-01-01

We have begun construction of a superconducting linac designed to accelerate ions from protons through about mass 60. Injected by our 9 MV-terminal tandem van de Graaff accelerator, the linac is expected to double the proton energy and quadruple the energies of heavier ions. The resonators are lead plated copper quarter wave structures. The overall layout and expected performance of the accelerator will be presented, along with a brief status report. 3 refs., 3 figs

All Digital IQ Servo-System for CERN Linacs

CERN Document Server

Broere, J; Garoby, R; Rohlev, A; Serrano, J

2004-01-01

A VME based control system has been developed and built at CERN for the servo loops regulating the field in linac accelerating structures. It is an all-digital system built on a single VME card, providing digital detection, processing, and modulation. It is foreseen to be used, in different versions, for the needs of both present and future CERN hadron linacs. The first application will be in the energy ramping RF chain of the CERN Heavy Ion Linac (linac 3). Design principle and the experimental results are described.

Upgrade of the controls for the Brookhaven linac

International Nuclear Information System (INIS)

Buxton, W.E.

1995-01-01

The control of the magnets, rf system, and other components at the Brookhaven Linac uses a system that was developed at Brookhaven in the late 1960's. This system will be retired in the summer of 1995. The Linac controls are being upgraded using modem VME-based hardware compatible with RHIC generation controls, and an existing serial field bus. The timing for the Linac will also be upgraded and will use components developed for RHIC. The controls in general, the timing for the Linac, and the modules developed will be described

Study on interference between far-IR to mm-wave CSR from consecutive electron bunches at BFEL RF-Linac

CERN Document Server

Biao, Z J; Xie Jia Li; Zhang Guo Qing

2001-01-01

Coherent bending magnet or undulator radiation due to a train of electron bunches is treated as radiation from a multi-slit diffraction array. Based on this model, we numerically analyse the interference among coherent synchrotron radiation emitted from consecutive bunches in a train of bunches, which are accelerated by a 30-MeV RF-linac at BFEL. Some interesting results are as follows: (1) Rapidly oscillating radiation enhancement due to interbunch interference is overlapped on the single bunch spectrum. (2) It consists of a series of spectrum lines corresponding to harmonics of the RF fundamental. (3) Main maximum positions are determined by the 'diffraction condition'. (4) Total intensity is about the square of the number of bunches participating in interference as single bunch intensity. Experimental design to measure interbunch interference at BFEL with the sub-mm and mm-wave Michelson interferometer is presented.

Commissioning the Linac Coherent Light Source injector

Directory of Open Access Journals (Sweden)

R. Akre

2008-03-01

Full Text Available The Linac Coherent Light Source is a SASE x-ray free-electron laser (FEL project presently under construction at SLAC [J. Arthur et al., SLAC-R-593, 2002.]. The injector section, from drive laser and rf photocathode gun through first bunch compressor chicane, was installed in the fall of 2006. The initial system commissioning with an electron beam was completed in August of 2007, with the goal of a 1.2-micron emittance in a 1-nC bunch demonstrated. The second phase of commissioning, including second bunch compressor and full linac, is planned for 2008, with FEL commissioning in 2009. We report experimental results and experience gained in the first phase of commissioning, including the photocathode drive laser, rf gun, photocathode, S-band and X-band rf systems, first bunch compressor, and the various beam diagnostics.

Analysis of phase velocity designing on superconducting section of proton Linac for spallation neutron source

International Nuclear Information System (INIS)

Ouyang Huafu; Xu Taoguang; Yu Qingchang; Guan Xialing; Luo Zihua

2001-01-01

A preliminary design of superconducting section of proton linac for spallation neutron source is made, which includes the design and optimization of the cavity shape and the architecture design of the superconducting section. In addition, the choice of the cell number of the superconducting cavity, the value of the geometric β G , the optimization principles of cavity and the beam dynamic properties are discussed

Fabrication, tests, and RF control of the 50 superconducting resonators of the Saclay heavy ion linac

International Nuclear Information System (INIS)

Cauvin, B.; Coret, M.; Fouan, J.P.

1988-01-01

Two types of niobium superconducting resonators are currently in use in the linac Outer cylinder and RF ports are identical for both designs but internal structures are different full wave helix (λ) with three gaps behavior or half-wave (λ/2) with two gaps behavior. The λ structure is based on a Karlsruhe design. All cavities (34 λ and 16 λ/2) are now fabricated, tested for field, and mounted in the eight machine cryostats. Resonator characteristics are listed. Frequencies are multiples of the low energy bunching frequency (13.5 MHz). The high magnetic fields arise at the welds joining helix to can (λ/2) or half-helices together (λ)

Application of superconductivity to intense proton linacs

International Nuclear Information System (INIS)

Heinrichs, H.

1996-01-01

Three examples of proposed superconducting linacs for intense particle beams are presented, and in two cases compared to normal conducting counterparts. Advantages and disadvantages of both types are discussed. Suggestions for future developments are presented. Finally a comparison of estimated operational costs of the normal and the superconducting linac for the ESS is given. (R.P.)

Drift tubes of Linac 2

CERN Multimedia

CERN PhotoLab

1977-01-01

With the advent of the 800 MeV PS Booster in 1972, the original injector of the PS, a 50 MeV Alvarez-type proton linac, had reached its limits, in terms of intensity and stability. In 1973 one therefore decided to build a new linac (Linac 2), also with a drift-tube Alvarez structure and an energy of 50 MeV. It had a new Cockcroft-Walton preinjector with 750 keV, instead of the previous one with 500 keV. Linac 2 was put into service in 1980. The old Linac 1 was then used for the study of, and later operation with, various types of ions. This picture shows Linac 2 drift-tubes, suspended on stems coming from the top, in contrast to Linac 1, where the drift-tubes stood on stems coming from the bottom.

Beam-based analysis of day-night performance variations at the SLC linac

International Nuclear Information System (INIS)

Decker, F.J.; Akre, R.; Assmann, R.; Bane, K.L.F.; Minty, M.G.; Phinney, N.; Spence, W.L.

1998-07-01

Diurnal temperature variations in the linac gallery of the Stanford Linear Collider (SLC) can affect the amplitude and phase of the rf used to accelerate the beam. The SLC employs many techniques for stabilization and compensation of these effects, but residual uncorrected changes still affect the quality of the delivered beam. This paper presents methods developed to monitor and investigate these errors through the beam response. Variations resulting from errors in the rf amplitude or phase can be distinguished by studying six different beam observables: betatron phase advance, oscillation amplitude growth, rms jitter along the linac, measurements of the beam phase with respect to the rf, changes in the required injection phase, and the global energy correction factor. By quantifying the beam response, an uncorrected variation of 14 degree (S-band) during 28 F temperature swings was found in the main rf drive line system between the front and end of the linac

LINAC4, A New $H^{-}$ Linear Injector at CERN

CERN Document Server

Garoby, R; Hanke, K; Lombardi, A M; Rossi, C; Vretenar, M

2004-01-01

Linac2, the present injector of the CERN PS Booster, limits the performance of the proton accelerator complex because of its low output energy (50 MeV). To remove this bottleneck, a higher energy linac is proposed (called â€ﾜLinac4†) which will double the brightness and the intensity of the beam delivered by the PSB and ensure the â€ﾜultimate” beam is available for LHC. Linac4 will deliver H- ions at a kinetic energy of 160 MeV. It is designed to be usable as the front-end of a future multi-GeV multi-MW linear accelerator, the â€ﾜSuperconducting Proton Linac” (SPL). R&D for Linac4 is now actively taking place with the support of the European Union through the Joint Research Activity HIPPI (â€ﾜHigh Intensity Pulsed Proton Injectors”), and of three ISTC projects involving three major Russian laboratories (BINP, IHEP and ITEP) and two nuclear centres (VNIIEF and VNIITF). The design of this new accelerator and the on-going developments are described.

Range of Possible Beam Current in Linac4

CERN Document Server

Lallement, J-B; CERN. Geneva. BE Department

2009-01-01

Linac4 is a new accelerator under construction at CERN. It is designed to accelerate H- ions to 160MeV, for injection into the existing Proton Synchrotron Booster (PSB). It is also the front-end of the SPL Linac, a high energy proton driver that will reach the energy of 5GeV. The Linac baseline design has been done for a nominal beam peak current of 70mA but it will certainly have to deal with different currents. 132 out of 155 quadrupoles in the Linac are permanent magnets, this choice of using PMQ having fixed gradient, mainly in the DTL and in the CCDTL may then entail issues concerning the beam transverse matching and quality from current different from the nominal one. In this paper, we present the beam dynamics performances in Linac4 obtained for different currents.

Failure Modes Analysis for the MSU-RIA Driver Linac

CERN Document Server

Wu, Xiaoyu; Gorelov, Dmitry; Grimm, Terry L; Marti, Felix; York, Richard

2005-01-01

Previous end-to-end beam dynamics simulation studies* using experimentally-based input beams including alignment and rf errors and variation in charge-stripping foil thickness have indicated that the Rare Isotope Accelerator (RIA) driver linac proposed by MSU has adequate transverse and longitudinal acceptances to accelerate light and heavy ions to final energies of at least 400 MeV/u with beam powers of 100 to 400 kW. During linac operation, equipment loss due to, for example, cavity contamination, availability of cryogens, or failure of rf or power supply systems, will lead to at least a temporary loss of some of the cavities and focusing elements. To achieve high facility availability, each segment of the linac should be capable of adequate performance even with failed elements. Beam dynamics studies were performed to evaluate the linac performance under various scenarios of failed cavities and focusing elements with proper correction schemes, in order to prove the flexibility and robustness of the driver ...

The Spallation Neutron Source RF Reference System

CERN Document Server

Piller, Maurice; Crofford, Mark; Doolittle, Lawrence; Ma, Hengjie

2005-01-01

The Spallation Neutron Source (SNS) RF Reference System includes the master oscillator (MO), local oscillator(LO) distribution, and Reference RF distribution systems. Coherent low noise Reference RF signals provide the ability to control the phase relationships between the fields in the front-end and linear accelerator (linac) RF cavity structures. The SNS RF Reference System requirements, implementation details, and performance are discussed.

RF power generation for future linear colliders

International Nuclear Information System (INIS)

Fowkes, W.R.; Allen, M.A.; Callin, R.S.; Caryotakis, G.; Eppley, K.R.; Fant, K.S.; Farkas, Z.D.; Feinstein, J.; Ko, K.; Koontz, R.F.; Kroll, N.; Lavine, T.L.; Lee, T.G.; Miller, R.H.; Pearson, C.; Spalek, G.; Vlieks, A.E.; Wilson, P.B.

1990-06-01

The next linear collider will require 200 MW of rf power per meter of linac structure at relatively high frequency to produce an accelerating gradient of about 100 MV/m. The higher frequencies result in a higher breakdown threshold in the accelerating structure hence permit higher accelerating gradients per meter of linac. The lower frequencies have the advantage that high peak power rf sources can be realized. 11.42 GHz appears to be a good compromise and the effort at the Stanford Linear Accelerator Center (SLAC) is being concentrated on rf sources operating at this frequency. The filling time of the accelerating structure for each rf feed is expected to be about 80 ns. Under serious consideration at SLAC is a conventional klystron followed by a multistage rf pulse compression system, and the Crossed-Field Amplifier. These are discussed in this paper

Status and Operation of the Linac4 Ion Source Prototypes

CERN Document Server

Lettry, J; Andersson, P; Bertolo, S; Butterworth, A; Coutron, Y; Dallocchio, A; Chaudet, E; Gil-Flores, J; Guida, R; Hansen, J; Hatayama, A; Koszar, I; Mahner, E; Mastrostefano, C; Mathot, S; Mattei, S; Midttun, O; Moyret, P; Nisbet, D; Nishida, K; O’Neil, M; Ohta, M; Paoluzzi, M; Pasquino, C; Pereira, H; Rochez, J; Sanchez Alvarez, J; Sanchez Arias, J; Scrivens, R; Shibata, T; Steyaert, D; Thaus, N; Yamamoto, T

2014-01-01

CERN’s Linac4 45 kV H- ion sources prototypes are installed at a dedicated ion source test stand and in the Linac4 tunnel. The operation of the pulsed hydrogen injection, RF sustained plasma and pulsed high voltages are described. The first experimental results of two prototypes relying on 2MHz RF- plasma heating are presented. The plasma is ignited via capacitive coupling, and sustained by inductive coupling. The light emitted from the plasma is collected by viewports pointing to the plasma chamber wall in the middle of the RF solenoid and to the plasma chamber axis. Preliminary measurements of optical emission spectroscopy and photometry of the plasma have been performed. The design of a cesiated ion source is presented. The volume source has produced a 45 keV H- beam of 16-22 mA which has successfully been used for the commissioning of the Low Energy Beam Transport (LEBT), Radio Frequency Quadrupole (RFQ) accelerator and chopper of Linac4.

Testing begins on Linac4

CERN Multimedia

Katarina Anthony

2012-01-01

On 3 August 2012, the Linac4 radiofrequency quadrupole (RFQ) module was installed at the accelerator test-stand in Building 152. The site will be the module’s home for almost a year, as the linear accelerator enters the assembly and testing stage.   Final module assembly is carried out before installation in Building 152.  Over the next Long Shutdown (LS2), Linac4 will replace the current Linac2 linear accelerator as the first link in CERN’s accelerator chain. It will deliver particles at 160 MeV to the PS Booster, more than triple the energy currently delivered by Linac2. But before the accelerator team can pop the champagne, the various elements of Linac4 will be tested and re-tested in facilities across CERN. “The first Linac4 tests are currently underway, starting with the CERN-built RFQ,” says Carlo Rossi, a physicist in the RF Group of the Beams (BE) Department and the RFQ project coordinator. “It’s an extremely impre...

High-charge s-band photocathode RF-gun and linac system for radiation research

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, Tetsuya; Uesaka, Mitsuru; Katsumura, Yousuke [Univ. of Tokyo, Graduate School of Engineering, Nuclear Engineering Research Laboratory, Tokai, Ibaraki (JP)] (and others)

2002-01-01

For sub-picosecond pump-and-prove-type radiation chemistry work, a new synchronized electron linac and laser system was installed in the Nuclear Engineering Research Laboratory (NERL) of University of Tokyo. The new laser system, with a Ti:Sapphire oscillator (795 nm) and amplifiers, generates 300 ps pulses at 10 Hz. The laser is transported through the vacuum chamber and then split into two beams. The first is compressed and converted to the third harmonics (265 nm, <250 {mu}J, 4-11 ps) so as to drive the photocathode RF-gun and generate a pump-electron beam. The second is compressed to 100 fs and used for the probe light. The high-power RF, which is provided by a new 15 MW klystron, is divided into the gun and the accelerating section. Finally, a time jitter of 330 fs (rms) was achieved between the pump-electron beam and the probe laser, which is equivalent to the design value of 320 fs. A charge of 7 nC/bunch was observed at the exit of the gun from this new laser system. Improvement of the vacuum in the gun (<10{sup -9} Torr) is the most effective way to obtain such a high-charge beam. After about three years of operation, the Cu photocathode has shown no degradation of quantum efficiency. (author)

Operation of the APS rf gun

International Nuclear Information System (INIS)

Lewellen, J. W.

1998-01-01

The Advanced Photon Source (APS) has a thermionic-cathode rf gun system capable of providing beam to the APS linac. The gun system consists of a 1.6-cell thermionic-cathode rf gun, a fast kicker for beam current control, and an alpha magnet for bunch compression and injection into the APS linac line. This system is intended for use both as an injector for positron creation, and as a first beam source for the Low-Energy Undulator Test Line (LEUTL) project [1]. The first measured performance characteristics of the gun are presented.

Discussion of high brightness rf linear accelerators

International Nuclear Information System (INIS)

Jameson, R.A.

1987-01-01

The fundamental aspects of high-brightness rf linacs are outlined, showing the breadth and complexity of the technology and indicating that synergism with advancements in other areas is important. Areas of technology reviewed include ion sources, injectors, rf accelerator structures, beam dynamics, rf power, and automatic control

Ion sources for induction linac driven heavy ion fusion

International Nuclear Information System (INIS)

Rutkowski, H.L.; Eylon, S.; Chupp, W.W.

1993-08-01

The use of ion sources in induction linacs for heavy ion fusion is fundamentally different from their use in the rf linac-storage rings approach. Induction linacs require very high current, short pulse extraction usually with large apertures which are dictated by the injector design. One is faced with the problem of extracting beams in a pulsed fashion while maintaining high beam quality during the pulse (low-emittance). Four types of sources have been studied for this application. The vacuum arc and the rf cusp field source are the plasma types and the porous plug and hot alumino-silicate surface source are the thermal types. The hot alumino-silicate potassium source has proved to be the best candidate for the next generation of scaled experiments. The porous plug for potassium is somewhat more difficult to use. The vacuum arc suffers from noise and lifetime problems and the rf cusp field source is difficult to use with very short pulses. Operational experience with all of these types of sources is presented

Ion sources for induction linac driven heavy ion fusion

International Nuclear Information System (INIS)

Rutkowski, H.L.; Eylon, S.; Chupp, W.W.

1994-01-01

The use of ion sources in induction linacs for heavy ion fusion is fundamentally different from their use in the rf linac-storage rings approach. Induction linacs require very high current, short pulse extraction usually with large apertures which are dictated by the injector design. One is faced with the problem of extracting beams in a pulsed fashion while maintaining high beam quality during the pulse (low emittance). Four types of sources have been studied for this application. The vacuum arc and the rf cusp field source are the plasma-types and the porous plug and hot alumino--silicate surface source are the thermal types. The hot alumino--silicate potassium source has proved to be the best candidate for the next generation of scaled experiments. The porous plug for potassium is somewhat more difficult to use. The vacuum arc suffers from noise and lifetime problems and the rf cusp field source is difficult to use with very short pulses. Operational experience with all of these types of sources is presented

Electron linac injector developments

International Nuclear Information System (INIS)

Fraser, J.S.

1986-01-01

There is a continuing demand for improved injectors for electron linacs. Free-electron laser (FEL) oscillators require pulse trains of high brightness and, in some applications, high average power at the same time. Wakefield-accelerator and laser-acceleration experiments require isolated bunches of high peak brightness. Experiments with alkali-halide photoemissive and thermionic electron sources in rf cavities for injector applications are described. For isolated pulses, metal photocathodes (illuminated by intense laser pulses) are being employed. Reduced emittance growth in high-peak-current electron injectors may be achieved by linearizing the cavity electric field's radial component and by using high field strengths at the expense of lower shunt impedance. Harmonically excited cavities have been proposed for enlarging the phase acceptance of linac cavities and thereby reducing the energy spread produced in the acceleration process. Operation of injector linacs at a subharmonic of the main linac frequency is also proposed for enlarging the phase acceptance

Radiotechnical Institute activity in the linac field

International Nuclear Information System (INIS)

Murin, B.P.

1976-01-01

For many years, the Radiotechnical Institute has been involved in a number of projects aimed at constructing linear accelerators for protons or electrons. This report summarizes the experience gained and covers 1) some problems of developing linacs to serve as meson or neutron generators, 2) results of study of a linac with asymmetric alternating phase focusing, and 3) electron linac projects. (author)

X-band RF power sources for accelerator applications

International Nuclear Information System (INIS)

Kirshner, Mark F.; Kowalczyk, Richard D.; Wilsen, Craig B.; True, Richard B.; Simpson, Ian T.; Wray, John T.

2011-01-01

The majority of medical and industrial linear accelerators (LINACs) in use today operate at S-band. To reduce size and weight, these systems are gradually migrating toward X-band. The new LINACs will require suitable RF components to power them. In anticipation of this market, L-3 Communications Electron Devices Division (EDD) has recently developed a suite of RF sources operating at 9.3 GHz to complement our existing S-band product line. (author)

Development of new S-band RF window for stable high-power operation in linear accelerator RF system

Science.gov (United States)

Joo, Youngdo; Lee, Byung-Joon; Kim, Seung-Hwan; Kong, Hyung-Sup; Hwang, Woonha; Roh, Sungjoo; Ryu, Jiwan

2017-09-01

For stable high-power operation, a new RF window is developed in the S-band linear accelerator (Linac) RF systems of the Pohang Light Source-II (PLS-II) and the Pohang Accelerator Laboratory X-ray Free-Electron Laser (PAL-XFEL). The new RF window is designed to mitigate the strength of the electric field at the ceramic disk and also at the waveguide-cavity coupling structure of the conventional RF window. By replacing the pill-box type cavity in the conventional RF window with an overmoded cavity, the electric field component perpendicular to the ceramic disk that caused most of the multipacting breakdowns in the ceramic disk was reduced by an order of magnitude. The reduced electric field at the ceramic disk eliminated the Ti-N coating process on the ceramic surface in the fabrication procedure of the new RF window, preventing the incomplete coating from spoiling the RF transmission and lowering the fabrication cost. The overmoded cavity was coupled with input and output waveguides through dual side-wall coupling irises to reduce the electric field strength at the waveguide-cavity coupling structure and the possibility of mode competitions in the overmoded cavity. A prototype of the new RF window was fabricated and fully tested with the Klystron peak input power, pulse duration and pulse repetition rate of 75 MW, 4.5 μs and 10 Hz, respectively, at the high-power test stand. The first mass-produced new RF window installed in the PLS-II Linac is running in normal operation mode. No fault is reported to date. Plans are being made to install the new RF window to all S-band accelerator RF modules of the PLS-II and PAL-XFEL Linacs. This new RF window may be applied to the output windows of S-band power sources like Klystron as wells as the waveguide windows of accelerator facilities which operate in S-band.

Measurements of longitudinal phase space in the SLC linac

International Nuclear Information System (INIS)

Bane, K.; Adolphsen, C.; Lavine, T.L.; Ross, M.; Seeman, J.; Thompson, K.

1990-05-01

In the Stanford Linear Collider the beam leaves a damping ring and then enters the Ring-to-Linac (RTL) transfer line. In the RTL it is compressed in length by a factor of 10 by means of an rf section, with which a longitudinally correlated energy variation is induced in the beam, and a following beam line which has non-zero momentum compaction. The compressed beam then enters the linac proper. In this paper we describe three measurements of longitudinal properties of the beam in the SLC linac. We present measurements of single bunch beam loading, of the energy spectrum at the end of the linac, and of the linac bunch length. Since the results of all three measurements depend on the beam's longitudinal charge distribution in the linac they, in turn, also depend on the bunch lengthening that occurs in the damping rings, as well as on the behavior of the compressor. The results of the first two measurements, in addition, depend critically on the strength of the longitudinal wakefields in the linac. The results of these three measurements are compared with simulations. For these calculations, at any given current, the potential well distortion in the damping ring is first computed. The compression process is then simulated to obtain the longitudinal charge distribution in the linac. For the first two measurements this distribution is then convolved with the calculated longitudinal wake function of the SLAC linac in order to obtain the induced voltage. Finally, the induced voltage is combined with the effect of the linac rf wave to give the final energy spectrum. 8 refs., 5 figs

Review of pulsed rf power generation

International Nuclear Information System (INIS)

Lavine, T.L.

1992-04-01

I am going to talk about pulsed high-power rf generation for normal-conducting electron and positron linacs suitable for applications to high-energy physics in the Next Linear Collider, or NLC. The talk will cover some basic rf system design issues, klystrons and other microwave power sources, rf pulse-compression devices, and test facilities for system-integration studies

High RF Power Production for CLIC

CERN Document Server

Syratchev, I; Adli, E; Taborelli, M

2007-01-01

The CLIC Power Extraction and Transfer Structure (PETS) is a passive microwave device in which bunches of the drive beam interact with the impedance of the periodically loaded waveguide and excite preferentially the synchronous mode. The RF power produced (several hundred MW) is collected at the downstream end of the structure by means of the Power Extractor and delivered to the main linac structure. The PETS geometry is a result of multiple compromises between beam stability and main linac RF power needs. Another requirement is to provide local RF power termination in case of accelerating structure failure (ON/OFF capability). Surface electric and magnetic fields, power extraction method, HOM damping, ON/OFF capability and fabrication technology were all evaluated to provide a reliable design

Resonance Excitation of Longitudinal High Order Modes in Project X Linac

Energy Technology Data Exchange (ETDEWEB)

Khabiboulline, T.N.; Sukhanov, A.AUTHOR = Awida, M.; Gonin, I.; Lunin, A.AUTHOR = Solyak, N.; Yakovlev, V.; /Fermilab

2012-05-01

Results of simulation of power loss due to excitation of longitudinal high order modes (HOMs) in the accelerating superconducting RF system of CW linac of Project X are presented. Beam structures corresponding to the various modes of Project X operation are considered: CW regime for 3 GeV physics program; pulsed mode for neutrino experiments; and pulsed regime, when Project X linac operates as a driver for Neutrino Factory/Muon Collider. Power loss and associated heat load due to resonance excitation of longitudinal HOMs are shown to be small in all modes of operation. Conclusion is made that HOM couplers can be removed from the design of superconducting RF cavities of Project X linac.

Resonance Excitation of Longitudinal High Order Modes in Project X Linac

International Nuclear Information System (INIS)

Gonin, I.V.; Khabiboulline, T.N.; Lunin, A.; Solyak, N.; Sukhanov, A.I.; Yakovlev, V.P.; Awida, M.H.

2012-01-01

Results of simulation of power loss due to excitation of longitudinal high order modes (HOMs) in the accelerating superconducting RF system of CW linac of Project X are presented. Beam structures corresponding to the various modes of Project X operation are considered: CW regime for 3 GeV physics program; pulsed mode for neutrino experiments; and pulsed regime, when Project X linac operates as a driver for Neutrino Factory/Muon Collider. Power loss and associated heat load due to resonance excitation of longitudinal HOMs are shown to be small in all modes of operation. Conclusion is made that HOM couplers can be removed from the design of superconducting RF cavities of Project X linac.

Moderator/collimator for a proton/deuteron linac to produce a high-intensity, high-quality thermal neutron beam for neutron radiography

International Nuclear Information System (INIS)

Singleterry, R.C. Jr.; Imel, G.R.; McMichael, G.E.

1995-01-01

Reactor based high resolution neutron radiography facilities are able to deliver a well-collimated (L/D ≥100) thermal flux of 10 6 n/cm 2 ·sec to an image plane. This is well in excess of that achievable with the present accelerator based systems such as sealed tube D-T sources, Van der Graaff's, small cyclotrons, or low duty factor linacs. However, continuous wave linacs can accelerate tens of milliamperes of protons to 2.5 to 4 MeV. The MCNP code has been used to analyze target/moderator configurations that could be used with Argonne's Continuous Wave Linac (ACWL). These analyses have shown that ACWL could be modified to generate a neutron beam that has a high intensity and is of high quality

Upgrade of the AGS H- linac

International Nuclear Information System (INIS)

Alessi, J.G.; Buxton, W.; Kponou, A.; LoDestro, V.; Mapes, M.; McNerney, A.J.; Raparia, D.

1994-01-01

The AGS linac presently accelerates 25 mA of H - to 200 MeV at a 5 Hz rep-rate and 500 μs pulse width. The Booster takes 4 pulses every 3.8 seconds, and the remaining pulses are used for isotope production. The authors are in the process of upgrading the linac to increase the average current delivered for isotope production by more than a factor of two, while at the same time expecting to decrease linac downtime. Various aspects of this upgrade are discussed, including the upgrade of the control system, new high power transmission line, transport line vacuum, and rf power supply system upgrades

Update of the Linac4-PSB Transfer Line

CERN Document Server

HEIN, Lutz

2010-01-01

The installation of Linac4 represents the first step of the upgrade plans of the CERN accelerator complex for the future in order to raise the available proton flux to attain amongst others the LHC ultimate luminosity. This linac is capable to accelerate H--ions from 45keV to 160MeV, which will be injected into the Proton Synchrotron Booster (PSB). The increase of energy from 50MeV (Linac2) to 160MeV (Linac4) allows to overcome the space charge limitations at the PSB injection, which is the main bottleneck towards higher beam brightness in the downstream accelerator chain. In order to preserve beam quality from the outlet of Linac4 to PSB injection the design of the transfer line becomes crucial. As the location of Linac4 was chosen in view of upgrade scenarios, the construction of a new transfer line is foreseen, see ref.[1] and ref.[2]. Here part of the Linac2-PSB transfer line will be re-used. In the new part of the transfer line the beam is horizontally and vertically adjusted towards the bending magnet B...

submitter Radiation Protection Studies for CERN LINAC4/SPL Accelerator Complex

CERN Document Server

Mauro, Egidio; Silari, Marco

2009-01-01

CERN is presently designing a new chain of accelerators to replace the present Proton Synchrotron (PS) complex: a 160 MeV room-temperature H$^-$ linac (Linac4) to replace the present 50 MeV proton linac injector, a 3.5 GeV Superconducting Proton Linac (SPL) to replace the 1.4 GeV PS booster (PSB) and a 50 GeV synchrotron (named PS2) to replace the 26 GeV PS. Linac4 has been funded and the civil engineering work started in October 2008, whilst the SPL is in an advanced stage of design. Beyond injecting into the future 50 GeV PS, the ultimate goal of the SPL is to generate a 4 MW beam for the production of intense neutrino beams. The radiation protection design is driven by the latter requirement. This thesis summarizes the radiation protection studies conducted for Linac4. FLUKA Monte Carlo simulations, complemented by analytical estimates, were performed 1) to evaluate the propagation of neutrons through the waveguide, ventilation and cable ducts placed along the accelerator, 2) to estimate the radiological i...

Los Alamos free-electron laser (FEL) rf system

International Nuclear Information System (INIS)

Tallerico, P.J.; Lynch, M.T.

1985-01-01

The FEL rf system was designed for 3.6-MW rf pulses from two klystrons to drive two linacs and one deflection cavity at 1300 MHz. Two 108.33-MHz subharmonic buncher cavities and one fundamental buncher were also built, each powered by a 5-kW amplifier. A single phase-coherent source drives the various amplifiers as well as the grid of the electron gun, which is pulsed at 21.67 MHz. The initial buncher system did not work as well as expected, and the first linac tank required more rf power than anticipated. The light output was extremely sensitive to amplitude and phase errors. More powerful klystrons were developed and installed, and a method was discovered for operating a single subharmonic buncher and allowing the first linac to complete the bunching process. This paper shows the actual configuration used to operate the laser and discusses future improvements

Commissioning of the Superconducting Linac at the Spallation Neutron Source (SNS)

International Nuclear Information System (INIS)

Kim, Sang-Ho; Campisi, Isidoro E.

2007-01-01

The use of superconducting radiofrequency (SRF) cavities in particle accelerator is becoming more widespread. Among the projects that make use of that technology is the Spallation Neutron Source, where H-ions are accelerated to about 1 GeV, mostly making use of niobium elliptical cavities. SNS will use the accelerated short (about 700 ns) sub-bunches of protons to generate neutrons by spallation, which will in turn allow probing structural and magnetic properties of new and existing materials. The SNS superconducting linac is the largest application of RF superconductivity to come on-line in the last decade. The SRF cavities, operated at 805 MHz, were designed, built and integrated into cryomodules at Jefferson Lab and installed and tested at SNS. SNS is also the first proton-like accelerator which uses SRF cavities in a pulse mode. Many of the details of the cavity performance are peculiar to this mode of operation, which is also being applied to lepton accelerators (TESLA test facility and X-FEL at DESY and the international linear collider project). Thanks to the low frequency of the SNS superconducting cavities, operation at 4.2 K has been possible without beam energy degradation, even though the cavities and cryogenic systems were originally designed for 2.1 K operation. The testing of the superconducting cavities, the operating experience with beam and the performance of the superconducting linac will be presented

Tuner Design for PEFP Superconducting RF Cavities

International Nuclear Information System (INIS)

Tang, Yazhe; An, Sun; Zhang, Liping; Cho, Yong Sub

2009-01-01

A superconducting radio frequency (SRF) cavity will be used to accelerate a proton beam after 100 MeV at 700 MHz in a linac of the Proton Engineering Frontier Project (PEFP) and its extended project. In order to control the SRF cavity's operating frequency at a low temperature, a new tuner has been developed for the PEFP SRF cavities. Each PEFP superconducting RF cavity has one tuner to match the cavity resonance frequency with the desired accelerator operating frequency; or to detune a cavity frequency a few bandwidths away from a resonance, so that the beam will not excite the fundamental mode, when the cavity is not being used for an acceleration. The PEFP cavity tuning is achieved by varying the total length of the cavity. The length of the cavity is controlled differentially by tuner acting with respect to the cavity body. The PEFP tuner is attached to the helium vessel and drives the cavity Field Probe (FP) side to change the frequency of the cavity

Multiple channel space lattice focusing and features of its use in applied RF linac

International Nuclear Information System (INIS)

Kushin, V.; Plotnikov, S.; Zarubin, A.; Bondarev, B.; Durkin, A.

2000-01-01

Nowadays the use of multiple channel accelerator systems is well known with some hundred channels helps us to increase total beam intensity proportional to the number of channels while the divergence of the total beam is roughly equal to the divergence of single channel. The accelerator structure for multiple beam linac must provide both transversal and longitudinal stability for every small beam taking into account Coulomb interactions of all the micro beams. The most convenient for accelerator structures with 100 and more beams are the systems that use RF focusing such as RFQ, APF and DTL with rectangular profiles. The common disadvantage of all those systems is connected with decreasing of focusing forces of RF field with particle velocity increase. Our analysis shows that the disadvantage may be overcome in structures with rectangular profiles. For this purpose some additional thin (3-5 mm) focusing electrodes called space lattices (SL) must be arranged within accelerator gaps. The distance between these electrodes is chosen roughly equal to the thickness of additional electrodes. The number of the electrodes must be increased with length of accelerator gaps and may be equal n=1,2...6 and even more. The arrangement of n thin electrodes in accelerator gaps helps us to reach qualitative change of accelerator structure parameters. Firstly, they make n times amplification of the sign-alternate component of RF focusing field without appreciable influence to phasing action of accelerating field. Secondly, introducing of additional electrodes that divide the gap on n small accelerator gaps provides beams shielding from each other within the region of beam acceleration in RF fields between drift tubes. The analysis shows that if n=4-6, it is possible to reach transversal stability of all particles independently of their input phases in RF field. On the other hand, the analysis shows that adiabatic change of synchronous phase at the input stage of acceleration helps us

Look at energy compression as an assist for high power rf production

International Nuclear Information System (INIS)

Birx, D.L.; Farkas, Z.D.; Wilson, P.B.

1984-01-01

The desire to construct electron linacs of higher and higher energies, coupled with the realities of available funding and real estate, has forced machine designers to reassess the limitations in both accelerator gradient (MeV/m) and energy. The gradients achieved in current radio-frequency (RF) linacs are sometimes set by electrical breakdown in the accelerating structure, but are in most cases determined by the RF power level available to drive the linac. In this paper we will not discuss RF power sources in general, but rather take a brief look at several energy compression schemes which might be of service in helping to make better use of the sources we employ. We will, however, diverge for a bit and discuss what the RF power requirements are. 12 references, 21 figures, 3 tables

Linac boosters for electrostatic machines

International Nuclear Information System (INIS)

Ben-Zvi, I.; Brookhaven National Lab., Upton, NY

1990-01-01

A survey of linacs which are used as boosters to electrostatic accelerators is presented. Machines both operating and under construction, copper and superconducting, are reviewed. The review includes data on the accelerating structures, performance, rf and control, beam optics, budget, vacuum and cryogenics. (orig.)

CEBAF Cryomodule Commissioning in the South Linac

International Nuclear Information System (INIS)

M. Drury; H. Lankford; T. Lee; J. Marshall; J. Preble; Q. Saulter; W. Schneider; Michael Spata; Mark Wiseman

1993-01-01

When complete, the Continuous Electron Beam Accelerator Facility will house a 4 GeV recirculating linear accelerator containing 42 1/4 cryomodules arrayed in two antiparallel linacs and an injector. Currently, 38 1/4 cryomodules have been installed. Each cryomodule contains eight superconducting niobium 5-cell rf cavities that operate at 1.497 GHz[1]. A cryomodule must provide an energy gain of 20 MeV to the 200 mu-A beam[2]. The resultant dynamic heat load must be less than 45 W. The cavity parameters that are measured during the commissioning process include the external Q's (Q(sub ext)) of the cavity ports, the unloaded Q (Q(sub 0)) of the cavity as a function of accelerating gradient, and the maximum operating gradient of the cavity[3]. Finally, the mechanical tuners are cycled and characterized. A portable test stand allows local control of the rf system and provides automated data acquisition. During the period from April 1993 through September 1993, 16 of the 20 cryomodules installed in the South Linac were commissioned. All cryomodules tested in the South Linac meet or exceed the CEBAF specifications. This paper describes the results of the commissioning of the first 10 cryomodules in the South Linac

Design and development of low level S-Band RF control system for IRFEL injector LINAC

International Nuclear Information System (INIS)

Mohania, Praveen; Mahawar, Ashish; Singh, Adarsh Pratap; Namdeo, Rajkumar; Baxy, Deodatta; Shrivastava, Purushottam

2015-01-01

A low level RF system has been designed and developed for phase and amplitude stabilization of S- Band microwave power being fed to fundamental buncher cavity and the injector LINAC structure of the Infra Red Free Electron Laser being developed at RRCAT Indore. The system uses analog phase shifters and voltage variable attenuators to control the phase and amplitude respectively, the control voltages for phase shifters and attenuators are generated using a 12 Bit ADC and is software controlled. The system has a slow feedback to correct phase and amplitude drifts occurring due to thermal variations and a fast feed forward mechanism to vary amplitude and phase of the output pulse to compensate beam loading and to shape the klystron output power. The present paper describes the design aspects of the LLRF system. (author)

Conceptual design of a linac-stretcher ring to obtain a 2-gev continuous electron beam

International Nuclear Information System (INIS)

Cho, Y.; Holt, R.J.; Jackson, H.E.; Khoe, T.K.; Mavrogenes, G.S.

1981-01-01

In order to obtain a high duty factor, >100 /mu/A 2-Gev electron beam, a linac-stretcher ring system was designed. The system is an attractive option because it draws heavily on the existing accelerator technology. The linac-stretcher ring consists of a 2-Gev SLAC-type pulsed linac which injects into a storage ring. In between linac pulses, the stored electron beam is to extract resonantly. This design differs from those discussed recently in several important respects. The storage ring includes an rf system whose purpose is to control the beam orbit and rate of extraction from the ring. With an rf system in the ring, the injection scheme consists of a few turns of synchronous transfers of beam between the linac and storage ring. 4 refs

Optimization of the beam extraction systems for the Linac4 H{sup −} ion source

Energy Technology Data Exchange (ETDEWEB)

Fink, D. A.; Lettry, J.; Scrivens, R.; Steyaert, D. [CERN, 1211 Geneva 23 (Switzerland); Midttun, Ø. [University of Oslo, P.O. Box 1048, 0316 Oslo (Norway); CERN, 1211 Geneva 23 (Switzerland); Valerio-Lizarraga, C. A. [Departamento de Investigación en Fisica, Universidad de Sonora, Hermosillo (Mexico); CERN, 1211 Geneva 23 (Switzerland)

2015-04-08

The development of the Linac 4 and its integration into CERN’s acceleration complex is part of the foreseen luminosity upgrade of the Large Hadron Collider (LHC). The goal is to inject a 160 MeV H{sup −} beam into the CERN PS Booster (PSB) in order to increase the beam brightness by a factor of 2 compared to the 50 MeV proton linac, Linac 2, that is currently in operation. The requirements for the ion source are a 45 keV H{sup −} beam of 80 mA intensity, 2 Hz repetition rate and 0.5 ms pulse length within a normalized rms-emittance of 0.25 mm· mrad. The previously installed beam extraction system has been designed for an H{sup −} ion beam intensity of 20 mA produced by an RF-volume source with an electron to H{sup −} ratio of up to 50. For the required intensity upgrades of the Linac4 ion source, a new beam extraction system is being produced and tested; it is optimized for a cesiated surface RF-source with a nominal beam current of 40 mA and an electron to H{sup −} ratio of 4. The simulations, based on the IBSIMU code, are presented. At the Brookhaven National Laboratory (BNL), a peak beam current of more than 100 mA was demonstrated with a magnetron H{sup −} source at an energy of 35 keV and a repetition rate of 2 Hz. A new extraction system is required to operate at an energy of 45 keV; simulation of a two stage extraction system dedicated to the magnetron is presented.

Design of 6 MeV X-band electron linac for dual-head gantry radiotherapy system

Science.gov (United States)

Shin, Seung-wook; Lee, Seung-Hyun; Lee, Jong-Chul; Kim, Huisu; Ha, Donghyup; Ghergherehchi, Mitra; Chai, Jongseo; Lee, Byung-no; Chae, Moonsik

2017-12-01

A compact 6 MeV electron linac is being developed at Sungkyunkwan University, in collaboration with the Korea atomic energy research institute (KAERI). The linac will be used as an X-ray source for a dual-head gantry radiotherapy system. X-band technology has been employed to satisfy the size requirement of the dual-head gantry radiotherapy machine. Among the several options available, we selected a pi/2-mode, standing-wave, side-coupled cavity. This choice of radiofrequency (RF) cavity design is intended to enhance the shunt impedance of each cavity in the linac. An optimum structure of the RF cavity with a high-performance design was determined by applying a genetic algorithm during the optimization procedure. This paper describes the detailed design process for a single normal RF cavity and the entire structure, including the RF power coupler and coupling cavity, as well as the beam dynamics results.

Low frequency RFQ linacs for heavy ion fusion

International Nuclear Information System (INIS)

Moretti, A.; Watson, J.M.; Martin, R.L.; Lari, R.J.; Stockley, R.L.

1982-01-01

Low frequency, radio frequency quadrupole (RFQ) structures are under study at Argonne National Laboratory (ANL) as the low-velocity portion of an rf linac driver for heavy ion inertial confinement fusion. Besides offering a direct comparison with the present ANL front end, it would provide a second low-velocity Xe +1 linac for funneling experiments at 22.9 MeV. Heavy ion RFQ accelerators are characterized by their low rf operating frequency of about 10 MHz. The large size of a manifold-fed four-vane, 10 MHz RFQ resonator structure (about 6 m in diameter) makes it unacceptable for heavy ions; therefore, alternate structures are under study at Argonne. The structures under study are: (1) a Wideroe-type structure with external stub lines, (2) a Wideroe-type structure with the stub lines internal to the structure, (3) a split coaxial line resonator with modulated vanes, and (4) a interdigital line resonator with modulated cylindrical rods. The split coaxial line resonator seems best at this low frequency. It is compact and very efficient. About 15.5 m of linac structure excited with 560 kW of rf power is sufficient to accelerate 30 mA of Xe +1 with 97% transmission efficiency from 250 keV to 3 MeV

The RF system of FELI

International Nuclear Information System (INIS)

Morii, Y.; Miyauchi, Y.; Koga, A.; Abe, H.; Keishi, T.; Bessho, I.; Tomimasu, T.

1994-01-01

FELI (Free Electron Laser Research Institute, Inc.) is constructing a Free Electron Laser facility covering from 20 μm (infra red region) to 0.35 μm (ultra violet region), using an S-band linac. The building will be completed in November 1993 and installation of the linac will start in December 1993. The linac consists of a thermoionic 0.5ns-pulse triggered gun, a 714 MHz SHB (subharmonic buncher), a 2856 MHz standing wave type buncher, and 7 ETL (Electrotechnical Laboratory) type accelerating sections. An RF system of the linac for FELs is required of long pulse duration and high stability. S-band klystrons (TOSHIBA E3729) are operated in three pulse operation modes (pulse width and peak RF power); 24 μs - 24 MW, 12.5 μs - 34 MW, 0.5 μs - 70 MW. Each klystron modulator has the PFN consisting of 4 parallel networks of 24 capacitors and 24 inductors, and it has a line switch of an optical thyristor stack. These equipments are manufactured now, and an S-band klystron and modulator will be combined to test their performance at the works of NISSIN ELECTRIC Co. in October 1993. (author)

ARIEL e-LINAC: Commissioning and Development

Science.gov (United States)

Laxdal, R. E.; Zvyagintsev, V.

2016-09-01

A superconducting electron Linac (e-Linac) will be a part of the ARIEL facility for the production of radioactive ion beams (RIB) at TRIUMF. The e-Linac will consist of five 1.3GHz 9-cell cavities in three cryomodules delivering a 50MeV 10mA beam. The baseline operation will be single pass but a re-circulating ring is planned to allow either energy boost or energy recovery operation. The first stage of the accelerator which consists of two cryomodules has been successfully commissioned in 2014. The paper will discuss the superconducting radio-frequency (SRF) challenges of the accelerator. Cavities, crymodules and RF system design, preparation, and performance will be presented.

ARIEL e-LINAC: Commissioning and Development

International Nuclear Information System (INIS)

Laxdal, R.E.; Zvyagintsev, V.

2016-01-01

A superconducting electron Linac (e-Linac) will be a part of the ARIEL facility for the production of radioactive ion beams (RIB) at TRIUMF. The e-Linac will consist of five 1.3GHz 9-cell cavities in three cryomodules delivering a 50MeV 10mA beam. The baseline operation will be single pass but a re-circulating ring is planned to allow either energy boost or energy recovery operation. The first stage of the accelerator which consists of two cryomodules has been successfully commissioned in 2014. The paper will discuss the superconducting radio-frequency (SRF) challenges of the accelerator. Cavities, crymodules and RF system design, preparation, and performance will be presented. (paper)

Inner structure of Linac 2

CERN Multimedia

CERN PhotoLab

1977-01-01

With the advent of the 800 MeV Booster in 1972, the original injector of the PS, a 50 MeV Alvarez-type proton linac, had reached its limits, in terms of intensity and stability. In 1973 one therefore decided to build a new linac (Linac 2), also with a drift-tube Alvarez structure and an energy of 50 MeV. It had a new Cockcroft-Walton preinjector with 750 keV, instead of the previous one with 500 keV. Linac 2 was put into service in 1980. The old Linac 1 was then used for the study of, and later operation with, various types of ions. This picture shows the inner structure of Linac 2, with drift-tubes hanging on stems under a rigid support structure, soon to be mounted inside tank 1 (750 keV to 10 MeV, the lowest-energy one of 3). Frank Malthouse is standing in the background.

Spin flipping a stored polarized proton beam with an rf magnetic field

International Nuclear Information System (INIS)

Hu, S.Q.; Blinov, B.B.; Caussyn, D.D.

1995-01-01

The authors studied the spin flipping of a vertically polarized, stored 139 MeV proton beam with an rf solenoid magnetic field. By sweeping the rf frequency through an rf depolarizing resonance, they made the spin flip. The spin flipping was more efficient for slower ramp times, and the spin flip efficiency peaked at some optimum ramp time that is not yet fully understood. Since frequent spin flipping could significantly reduce the systematic errors in scattering experiments using a stored polarized beam, it is very important to minimize the depolarization after each spin flip. In this experiment, with multiple spin flips, the authors found a polarization loss of 0.0000 ± 0.0005 per spin flip under the best conditions; this loss increased significantly for small changes in the conditions

Beam position monitoring in the AGS Linac to Booster transfer line

International Nuclear Information System (INIS)

Shea, T.J.; Brodowski, J.; Witkover, R.

1991-01-01

A beam position monitor system has been developed and used in the commissioning of Brookhaven's Linac to Booster transfer line. This line transports a chopped, RF modulated H- beam from the 200 MeV Linac to the AGS Booster. Over a 15dB dynamic range in beam current, the position monitor system provides a real-time, normalized position signal with an analog bandwidth of about 20 MHz. Seven directional coupler style pickups are installed in the line with each pickup sensing both horizontal and vertical position. Analog processing electronics are located in the tunnel and incorporate the amplitude modulation to phase modulation normalization technique. To avoid interference from the 200 MHz linac RF system, processing is performed at 400 MHz. This paper provides a system overview and report results from the commissioning experience

Conceptual design of a linac-stretcher ring to obtain a 2-GeV continuous electron beam

International Nuclear Information System (INIS)

Cho, Y.; Holt, R.J.; Jackson, H.E.; Khoe, T.K.; Mavrogenes, G.S.

1981-01-01

In order to obtain a high duty factor, > 100 μA 2-GeV electron beam, we have designed a linac-stretcher ring system. The system is an attractive option because it draws heavily on the existing accelerator technology. The linac-stretcher ring consists of a 2-GeV SLAC-type pulsed linac which injects into a storage ring. In between linac pulses, the stored electron beam is to extract resonantly. This design differs from those discussed recently in several important respects. The storage ring includes an RF system whose purpose is to control the beam orbit and rate of extraction from the ring. With an RF system in the ring, the injection scheme consists of a few turns of synchronous transfers of beam between the linac and storage ring

S-band linac-based X-ray source with {pi}/2-mode electron linac

Energy Technology Data Exchange (ETDEWEB)

Deshpande, Abhay, E-mail: abhay@post.kek.jp [Department of Accelerator Science, School of High Energy Accelerator Science, Graduate University for Advanced Studies, Shonan International Village, Hayama, Miura, Kanagawa 240-0193 (Japan); Society for Applied Microwave Electronic Engineering and Research (SAMEER), R and D Laboratory of the Government of India, IIT Campus, Powai, Mumbai 400 076 (India); Araki, Sakae [High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Dixit, Tanuja [Society for Applied Microwave Electronic Engineering and Research (SAMEER), R and D Laboratory of the Government of India, IIT Campus, Powai, Mumbai 400 076 (India); Fukuda, Masafumi [High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Krishnan, R; Pethe, Sanjay [Society for Applied Microwave Electronic Engineering and Research (SAMEER), R and D Laboratory of the Government of India, IIT Campus, Powai, Mumbai 400 076 (India); Sakaue, Kazuyuki [Waseda University, Shinjuku-ku, Tokyo 169-8555 (Japan); Terunuma, Nobuhiro; Urakawa, Junji [High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Washio, Masakazu [Waseda University, Shinjuku-ku, Tokyo 169-8555 (Japan)

2011-05-01

The activities with the compact X-ray source are attracting more attention, particularly for the applications of the source in medical fields. We propose the fabrication of a compact X-ray source using the SAMEER electron linear accelerator and the KEK laser undulator X-ray source (LUCX) technologies. The linac developed at SAMEER is a standing wave side-coupled S-band linac operating in the {pi}/2 mode. In the proposed system, a photocathode RF gun will inject bunches of electrons in the linac to accelerate and achieve a high-energy, low-emittance beam. This beam will then interact with the laser in the laser cavity to produce X-rays of a type well suited for various applications. The side-coupled structure will make the system more compact, and the {pi}/2 mode of operation will enable a high repetition rate operation, which will help to increase the X-ray yield.

Reliability model of SNS linac (spallation neutron source-ORNL)

International Nuclear Information System (INIS)

Pitigoi, A.; Fernandez, P.

2015-01-01

A reliability model of SNS LINAC (Spallation Neutron Source at Oak Ridge National Laboratory) has been developed using risk spectrum reliability analysis software and the analysis of the accelerator system's reliability has been performed. The analysis results have been evaluated by comparing them with the SNS operational data. This paper presents the main results and conclusions focusing on the definition of design weaknesses and provides recommendations to improve reliability of the MYRRHA ( linear accelerator. The reliability results show that the most affected SNS LINAC parts/systems are: 1) SCL (superconducting linac), front-end systems: IS, LEBT (low-energy beam transport line), MEBT (medium-energy beam transport line), diagnostics and controls; 2) RF systems (especially the SCL RF system); 3) power supplies and PS controllers. These results are in line with the records in the SNS logbook. The reliability issue that needs to be enforced in the linac design is the redundancy of the systems, subsystems and components most affected by failures. For compensation purposes, there is a need for intelligent fail-over redundancy implementation in controllers. Enough diagnostics has to be implemented to allow reliable functioning of the redundant solutions and to ensure the compensation function

Optimization of Beam Transmission of PAL-PNF Electron Linac

Energy Technology Data Exchange (ETDEWEB)

Shin, S. G.; Kim, S. K.; Kim, E. A. [Pohang University of Science and Technology, Pohang (Korea, Republic of)

2012-05-15

The PNF (Pohang Neutron Facility) electron Linac is providing converted neutrons and photons from electron beams to users for nuclear physics experiments and high energy gamma-ray exposures. This linac is capable of producing 100 MeV electron beams with a beam current of pulsed 100 mA. The pulse length is 2 {mu}s and the pulse repetition rate is typically 30 Hz. This linac consists of two SLAC-type S-band accelerating columns and the thermionic RF gun. They are powered by one klystron and the matching pulse modulator. The electron beams emitted from the RF gun are bunched as they pass through the alpha magnet and are injected into the accelerating column thereafter. In this paper, we discuss procedures and results of the beam transmission optimization with technical details of the accelerator system. We also briefly discuss the future upgrade plan to obtain short-pulse or electron beams for neutron TOF experiments by adopting a triode type thermionic DC electron gun

Proton linacs for boron neutron capture therapy

International Nuclear Information System (INIS)

Lennox, A.J.

1993-08-01

Recent advances in the ability to deliver boron-containing drugs to brain tumors have generated interest in ∼4 MeV linacs as sources of epithermal neutrons for radiation therapy. In addition, fast neutron therapy facilities have been studying methods to moderate their beams to take advantage of the high cross section for epithermal neutrons on boron-10. This paper describes the technical issues involved in each approach and presents the motivation for undertaking such studies using the Fermilab linac. the problems which must be solved before therapy can begin are outlined. Status of preparatory work and results of preliminary measurements are presented

Development of new S-band SLED for PAL-XFEL Linac

Energy Technology Data Exchange (ETDEWEB)

Joo, Youngdo; Park, Yongjung; Heo, Hoon; Heo, Jinyul; Park, Sung-Soo; Kim, Sang-Hee; Kim, Kwang-Hoon; Kang, Heung-Sik [Pohang Accelerator Laboratory, Pohang, Gyeongbuk 37673 (Korea, Republic of); Lee, Heung-Soo, E-mail: lhs@postech.ac.kr [Pohang Accelerator Laboratory, Pohang, Gyeongbuk 37673 (Korea, Republic of); Noh, Sungju; Oh, Kyoungmin [VitzroTech, Ansan, Gyeonggi 15603 (Korea, Republic of)

2017-01-21

In order to achieve beam acceleration to the beam energy of 10 GeV at the end of its 716 m-long linear accelerator (Linac), the Pohang Accelerator Laboratory X-ray Free Electron Laser (PAL-XFEL) is going to operate the Stanford Linear Accelerator Energy Doubler (SLED) at the maximum klystron output peak power of 80 MW, with a pulse length of 4 μs, and at a repetition rate of 60 Hz. The original SLED that had been used in Pohang Light Source-II (PLS-II) can no longer sustain such a high-power operation because excessive radiation caused by RF breakdown has been frequently detected even at the lower klystron peak power during the PLS-II operation. Therefore, a new SLED is designed by modifying both the 3-dB power hybrid and the waveguide-cavity coupling structure of the original SLED where the excessive radiation has been mainly detected. The finite-difference time-domain (FDTD) simulation in the CST Microwave Studio shows that the new SLED has a peak electric field and a surface current lower than those of the original SLED at the same level of the RF input peak power, which would secure stable high-power operation. All of the 42 SLEDs in the PAL-XFEL Linac are newly fabricated and installed. During the RF conditioning of the PAL-XFEL Linac, no significant vacuum and radiation issue was found in the new SLEDs. Finally, the accelerated electron beam energy of 10 GeV obtained at the end of the PAL-XFEL Linac verified that the RF performance of the new SLED is stable.

Development of new S-band SLED for PAL-XFEL Linac

Science.gov (United States)

Joo, Youngdo; Park, Yongjung; Heo, Hoon; Heo, Jinyul; Park, Sung-Soo; Kim, Sang-Hee; Kim, Kwang-Hoon; Kang, Heung-Sik; Lee, Heung-Soo; Noh, Sungju; Oh, Kyoungmin

2017-01-01

In order to achieve beam acceleration to the beam energy of 10 GeV at the end of its 716 m-long linear accelerator (Linac), the Pohang Accelerator Laboratory X-ray Free Electron Laser (PAL-XFEL) is going to operate the Stanford Linear Accelerator Energy Doubler (SLED) at the maximum klystron output peak power of 80 MW, with a pulse length of 4 μs, and at a repetition rate of 60 Hz. The original SLED that had been used in Pohang Light Source-II (PLS-II) can no longer sustain such a high-power operation because excessive radiation caused by RF breakdown has been frequently detected even at the lower klystron peak power during the PLS-II operation. Therefore, a new SLED is designed by modifying both the 3-dB power hybrid and the waveguide-cavity coupling structure of the original SLED where the excessive radiation has been mainly detected. The finite-difference time-domain (FDTD) simulation in the CST Microwave Studio shows that the new SLED has a peak electric field and a surface current lower than those of the original SLED at the same level of the RF input peak power, which would secure stable high-power operation. All of the 42 SLEDs in the PAL-XFEL Linac are newly fabricated and installed. During the RF conditioning of the PAL-XFEL Linac, no significant vacuum and radiation issue was found in the new SLEDs. Finally, the accelerated electron beam energy of 10 GeV obtained at the end of the PAL-XFEL Linac verified that the RF performance of the new SLED is stable.

The use the a high intensity neutrino beam from the ESS proton linac for measurement of neutrino CP violation and mass hierarchy

CERN Document Server

Baussan, E.; Ekelof, T.; Martinez, E.Fernandez; Ohman, H.; Vassilopoulos, N.

2012-01-01

It is proposed to complement the ESS proton linac with equipment that would enable the production, concurrently with the production of the planned ESS beam used for neutron production, of a 5 MW beam of 10$^{23}$ 2.5 GeV protons per year in microsecond short pulses to produce a neutrino Super Beam, and to install a megaton underground water Cherenkov detector in a mine to detect $\

Crossbar H-mode drift-tube linac design with alternative phase focusing for muon linac

Science.gov (United States)

Otani, M.; Futatsukawa, K.; Hasegawa, K.; Kitamura, R.; Kondo, Y.; Kurennoy, S.

2017-07-01

We have developed a Crossbar H-mode (CH) drift-tube linac (DTL) design with an alternative phase focusing (APF) scheme for a muon linac, in order to measure the anomalous magnetic moment and electric dipole moment (EDM) of muons at the Japan Proton Accelerator Research Complex (J-PARC). The CH-DTL accelerates muons from β = v/c = 0.08 to 0.28 at an operational frequency of 324 MHz. The design and results are described in this paper.

Development of an IH-type linac for the acceleration of high current heavy ion beams

Energy Technology Data Exchange (ETDEWEB)

Haehnel, Jan Hendrik

2017-07-20

The Facility for Antiproton and Ion Research (FAIR) at GSI Darmstadt will provide unprecedented intensities of protons and heavy ions up to uranium at energies of up to 29 GeV for protons and 2.7 GeV/u for U{sup 28+}. To achieve high intensities in the synchrotron accelerators, high beam currents have to be provided by the injector linear accelerators. High current heavy ion beams are provided by the Universal Linear Accelerator (UNILAC), which in its current state will not be able to provide the required FAIR beam currents. This thesis deals with the development of upgrades for the UNILAC to ensure its high current capability. The first improvement is a matching section (MEBT) for the interface between the RFQ and the IH-DTL of the existing high current injector HSI at the UNILAC. With this new MEBT section, particle losses are eliminated and the overall beam quality is improved. As a second improvement, a complete replacement of the existing Alvarez-DTL is presented. A combination of efficient IH-type cavities and KONUS beam dynamics results in a reduction of the linac length from about 60 m (Alvarez) to just 23 m (new IH-DTL) while providing the same energy and fulfilling FAIR requirements of a high beam current and beam quality. This thesis contains a detailed beam dynamics design of the new linac including some fundamental investigations of the KONUS beam dynamics concept. A cross-check of the beam dynamics design was performed with two independent multi-particle simulation codes. Detailed error studies were conducted to investigate the influence of manufacturing, alignment and operating errors on the beam dynamics performance. Additionally, all five linac cavities were designed, optimized, and their RF parameters including power requirements calculated to provide a comprehensive linac design.

Development of an IH-type linac for the acceleration of high current heavy ion beams

International Nuclear Information System (INIS)

Haehnel, Jan Hendrik

2017-01-01

The Facility for Antiproton and Ion Research (FAIR) at GSI Darmstadt will provide unprecedented intensities of protons and heavy ions up to uranium at energies of up to 29 GeV for protons and 2.7 GeV/u for U 28+ . To achieve high intensities in the synchrotron accelerators, high beam currents have to be provided by the injector linear accelerators. High current heavy ion beams are provided by the Universal Linear Accelerator (UNILAC), which in its current state will not be able to provide the required FAIR beam currents. This thesis deals with the development of upgrades for the UNILAC to ensure its high current capability. The first improvement is a matching section (MEBT) for the interface between the RFQ and the IH-DTL of the existing high current injector HSI at the UNILAC. With this new MEBT section, particle losses are eliminated and the overall beam quality is improved. As a second improvement, a complete replacement of the existing Alvarez-DTL is presented. A combination of efficient IH-type cavities and KONUS beam dynamics results in a reduction of the linac length from about 60 m (Alvarez) to just 23 m (new IH-DTL) while providing the same energy and fulfilling FAIR requirements of a high beam current and beam quality. This thesis contains a detailed beam dynamics design of the new linac including some fundamental investigations of the KONUS beam dynamics concept. A cross-check of the beam dynamics design was performed with two independent multi-particle simulation codes. Detailed error studies were conducted to investigate the influence of manufacturing, alignment and operating errors on the beam dynamics performance. Additionally, all five linac cavities were designed, optimized, and their RF parameters including power requirements calculated to provide a comprehensive linac design.

The application and study of an oxide-impregnated nickel-matrix cathode for Beijing proton linac

International Nuclear Information System (INIS)

Xia Dehong; Shi Rongjian

1996-01-01

A low power consumption oxide-impregnated nickel-matrix cathode used in the Duoplasmatron ion source of the Beijing Proton Linac (BPL) is presented. Its structure, treatment process of nickel-foam rubber on metal matrix surface and manufacture of dip coating carbonate are briefly introduced. The activation method and experiment results of the cathode are described. The principal factors which influence the cathode lifetime are discussed. The lifetime of the cathode is up to 2110 h while the extracted pulsed beam current is about 200 mA

Analysis of the FEL-RF interaction in recirculating, energy-recovering linacs with an FEL

CERN Document Server

Merminga, L; Benson, S; Bolshakov, A; Doolittle, L; Neil, George R

1999-01-01

Recirculating, energy-recovering linacs can be used as driver accelerators for high power FELs. Instabilities which arise from fluctuations of the cavity fields are investigated. Energy changes can cause beam loss on apertures, phase oscillations and optical cavity detuning. These effects in turn cause changes in the laser output power through a time-varying FEL gain function. All three effects change the beam-induced voltage in the cavities and can lead to unstable variations of the accelerating field and output laser power. We have developed a model of the coupled system and solved it both analytically and numerically. It includes the beam-cavity interaction, low level RF feedback, and the electron-photon interaction. The latter includes the FEL gain function in terms of cavity detuning, energy offset, and is valid both in the small signal gain and in the saturated regimes. We have demonstrated that in the limit of small perturbations, the linear theory agrees with the numerical solutions and have performed...

The linac control system for the large-scale synchrotron radiation facility (SPring-8)

Energy Technology Data Exchange (ETDEWEB)

Sakaki, Hironao; Yoshikawa, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Itoh, Yuichi [Atomic Energy General Services Corporation, Tokai, Ibaraki (Japan); Terashima, Yasushi [Information Technology System Co., Ltd. (ITECS), Tokyo (Japan)

2000-09-01

The linac for large-scale synchrotron radiation facilities has been operated since August of 1996. The linac deal with the user requests without any big troubles. In this report, the control system development policy, details, and the operation for the linac are presented. It is also described so that these experiences can be used for control system of a large scale proton accelerators which will be developed in the High Intensity Proton Accelerator Project. (author)

Design study on an intense heavy-ion linac system

International Nuclear Information System (INIS)

Okamura, M.; Oguri, Y.; Takahashi, Y.; Hattori, T.; Takeda, O.; Satoh, K.; Tanabe, Y.

1992-01-01

A four-vane RFQ cavity is designed for an intense heavy-ion linac system. RFQ-vanes with small tip curvatures are applied in order to improve the RF power efficiency. Beam optical and RF parameters are investigated by beams of numerical methods. Using a scale model, the cavity structure is experimentally optimized. (Author) 7 refs., 4 figs

The room temperature CH-DTL and its application for the FAIR proton injector

International Nuclear Information System (INIS)

Clemente, Gianluigi

2007-01-01

In the first chapter the essential parameters of a RF structure are presented. Also the beam dynamics in a linear accelerator is entered. Especially the conditions for stable longitudinal and transverse beam dynamics are treated. The second chapter describes the lay-out of the crossbar drift-tube linac (CH-DTL). The principle of a H-mode structure as well as the actual status of the development of such structures is explained. The last chapter is dedicated to the lay-out of the beam focusing in the DTL section of the FAIR proton linac. The concluding part of the thesis deals with studies on beam losses under assumption of realistic tolerances concerning the HF fields and adjustments of beam-guiding components

The room temperature CH-DTL and its application for the FAIR proton injector

Energy Technology Data Exchange (ETDEWEB)

Clemente, Gianluigi

2007-07-01

In the first chapter the essential parameters of a RF structure are presented. Also the beam dynamics in a linear accelerator is entered. Especially the conditions for stable longitudinal and transverse beam dynamics are treated. The second chapter describes the lay-out of the crossbar drift-tube linac (CH-DTL). The principle of a H-mode structure as well as the actual status of the development of such structures is explained. The last chapter is dedicated to the lay-out of the beam focusing in the DTL section of the FAIR proton linac. The concluding part of the thesis deals with studies on beam losses under assumption of realistic tolerances concerning the HF fields and adjustments of beam-guiding components.

Gas Injection And Fast Pressure-Rise Measurements For The Linac4 H− Source

CERN Document Server

Mahner, E; Lettry, J; Mattei, S; O'Neil, M; Neupert, H; Pasquino, C; Schmitzer, C

2013-01-01

In the era of the Large Hadron Collider, the CERN injector complex comprising the 34 years old Linac2 with its primary proton source, is presently upgraded with a new linear accelerator for H− (Linac4). The design, construction, and test of volume production and cesiated RF-driven H− ion sources is presently ongoing with the final goal of producing an H− beam with 80 mA beam current, 45 keV beam energy, 500 s pulse length, and a repetition rate of 2 Hz. In order to have quantitative information of the hydrogen gas density at the moment of plasma ignition the dynamic vacuum properties of the plasma generator were studied experimentally. We describe the experimental setup and present fast pressure-rise measurements for different parameters of the gas injection system, such as gas species (H2, He, N2, Ar), piezo valve voltage pulse length (200 - 500 s), and injection pressure (400 - 2800 mbar). The obtained data are compared with a conductance model of the plasma generator.

CERN Linac4. The space charge challenge

Energy Technology Data Exchange (ETDEWEB)

Hein, Lutz Matthias

2013-08-06

In the first phase of the upgrade program of the CERN accelerator complex the proton injector Linac2 will be replaced by a new, normal-conducting H-ion Linac, Linac4, allowing a significant increase of the proton flux intensity along the downstream accelerator complex. In the design of Linac4 three beam transport sections are implemented to match the beam between the different accelerator elements and to model the longitudinal pulse structure. These three beam transport sections, which are the most critical locations in terms of beam quality preservation, are in the focus of this thesis. During the work of this thesis the Low Energy Beam Transport (LEBT), which is required to match the source beam to the radiofrequency quadrupole (RFQ), has been commissioned and its beam dynamics re-constructed. The measurement campaign used to reconstruct the LEBT beam dynamics was performed with the aim to prepare the RFQ commissioning and to maximise the LEBT performance. Downstream of the Linac4 accelerator the beam is transported along a 180 m long transfer line to the Proton Synchrotron Booster (PS-Booster). The transfer line optics was studied, optimised and sections were completely re-designed. The new transfer line optics is characterised by an improved preservation of the beam emittance, higher stability of the optical solution with respect to alignment errors and field jitters of the transfer line magnets and it is matched to each of the PS-Booster injection schemes. In a concluding ''Start-To-End'' simulation based on the measured beam characteristics at the LEBT exit the beam dynamics of the downstream Linac, including the transfer line, was calculated. To minimise particle losses within acceptable emittance preservation the beam optics of the Medium Energy Beam Transport (MEBT) was adapted to the measured beam parameters. This ''Start-To-End'' simulation was performed to identify critical sections of the Linac4 beam dynamics and

LINAC4 low energy beam measurements

CERN Document Server

Hein, L M; Lallement, J B; Lombardi, A M; Midttun, O; Posocco, P; Scrivens, R

2012-01-01

Linac4 is a 160 MeV normal-conducting linear accelerator for negative Hydrogen ions (H−), which will replace the 50 MeV proton Linac (Linac2) as linear injector for the CERN accelerators. The low energy part, comprising a 45 keV Low Energy Beam Transport system (LEBT), a 3 MeV Radiofrequency Quadrupole (RFQ) and a Medium Energy Beam Transport (MEBT) is being assembled in a dedicated test stand for pre-commissioning with a proton beam. During 2011 extensive measurements were done after the source and after the LEBT with the aim of preparing the RFQ commissioning and validating the simulation tools, indispensable for future source upgrades. The measurements have been thoroughly simulated with a multi-particle code, including 2D magnetic field maps, error studies, steering studies and the generation of beam distribution from measurements. Emittance, acceptance and transmission measurements will be presented and compared to the results of the simulations.

High Gradient Accelerating Structures for Carbon Therapy Linac

Energy Technology Data Exchange (ETDEWEB)

Kutsaev, Sergey; Agustsson, R.; Faillace, L.; Goel, A.; Mustapha, B.; Nassiri, A.; Ostroumov, P.; Plastun, A.; Savin, E.

2016-05-01

Carbon therapy is the most promising among techniques for cancer treatment, as it has demonstrated significant improvements in clinical efficiency and reduced toxicity profiles in multiple types of cancer through much better localization of dose to the tumor volume. RadiaBeam, in collaboration with Argonne National Laboratory, are developing an ultra-high gradient linear accelerator, Advanced Compact Carbon Ion Linac (ACCIL), for the delivery of ion-beams with end-energies up to 450 MeV/u for 12C6+ ions and 250 MeV for protons. In this paper, we present a thorough comparison of standing and travelling wave designs for high gradient S-Band accelerating structures operating with ions at varying velocities, relative to the speed of light, in the range 0.3-0.7. In this paper we will compare these types of accelerating structures in terms of RF, beam dynamics and thermo-mechanical performance.

Development of an RFQ linac for unstable nuclei

International Nuclear Information System (INIS)

Arai, S.; Imanishi, A.; Morimoto, T.; Shibuya, S.; Tojyo, E.; Tokuda, N.

1990-05-01

A split coaxial RFQ (SCRFQ) is being developed for accelerating unstable nuclei with a charge-to-mass ratio larger than 1/60 from 1 to 170 keV/u in the JHP heavy-ion linac. The SCRFQ is equipped with modulated vanes to generate ideal quadrupole and accelerating fields. The fundamental problems on the SCRFQ have been clarified and solved through studies on a cold model, and the excellent accelerating performance has been confirmed by using a proton accelerating model working at 50 MHz. A 25.5-MHz prototype for the JHP SCRFQ is now under development. The prototype, 2.1 m in length and 0.9 m in diameter, will accelerate ions with a charge-to-mass ratio larger than 1/30 from 1 to 45 keV/u. Low-power tests conducted so far show that the prototype cavity has good rf characteristics. (author)

Versatile rf controller

International Nuclear Information System (INIS)

Howard, D.

1985-05-01

The low level rf system developed for the new Bevatron local injector provides precise control and regulation of the rf phase and amplitude for three 200 MHz linac cavities. The main features of the system are: extensive use of inexpensive, off-the-shelf components, ease of maintenance, and adaptability to a wide range of operation frequencies. The system utilizes separate function, easily removed rf printed circuit cards interconnected via the edge connectors. Control and monitoring are available both locally and through the computer. This paper will describe these features as well as the few component changes that would be required to adapt the techniques to other operating frequencies. 2 refs

3D Emittances Tailoring Techniques and Optimization with Space Charge for the Future CERN PS Booster Operations with Linac4

CERN Document Server

Forte, Vincenzo; Benedetto, Elena; Bracco, Chiara; Cieslak-Kowalska, Magdalena; Di Giovanni, Gian Piero

2016-01-01

In the frame of the LIU (LHC Injectors Upgrade) project, the CERN PS Booster is going to be renovated to host a new H⁻ charge-exchange injection from the Linac4. One important feature of the new injection scheme is the possibility to tailor a wide range of 3D emittances for CERN's different users in an intensity span in the order of 5·10⁹ to 1.6·10¹³ protons per PSB ring. This paper gives an overview of 3D multi-turn injection techniques, focusing on the future LHC beams, which aim at reaching high brightness, and on highest intensity beams (ISOLDE), where losses are the main concern. Complete RF capture simulations and transverse injection maps, including space charge effects, are presented and also intended to be used during the commissioning with Linac4.

Reduction of losses in linacs for protons or heavy ions

International Nuclear Information System (INIS)

Claus, J.

1977-01-01

It is necessary to minimize the beam losses in linacs for high average currents in order to avoid serious problems due to radiation damage, dissipation and radio activation of the accelerator structure. A large part of the losses in existing linacs is due to incomplete bunching of the injected beam. Proposed improvements generally appear to be deficient in one or more respects if applied to linacs with conventional frequencies, injection energies and current densities. By preceding the linac proper with an accelerating structure and an energy analyzer, it becomes possible to separate the particles that remained outside the buckets from those that are inside so that they can be dumped in a controlled manner

CERN Linac4 - The Space Charge Challenge Design and Commission

CERN Document Server

Hein, Lutz Matthias; Holzer, Bernhard

In the first phase of the upgrade program of the CERN accelerator complex the proton injector Linac2 will be replaced by a new, normal-conducting $H^-$ ion Linac, Linac4, allowing a significant increase of the proton flux intensity along the downstream accelerator complex. In the design of Linac4 three beam transport sections are implemented to match the beam between the different accelerator elements and to model the longitudinal pulse structure. These three beam transport sections, which are the most critical locations in terms of beam quality preservation, are in the focus of this thesis. During the work of this thesis the low energy beam transport (LEBT), which is required to match the source beam to the radiofrequency quadrupole (RFQ), has been commissioned and its beam dynamics re-constructed. The measurement campaign used to re-construct the LEBT beam dynamics was performed with the aim to prepare the RFQ commissioning and to maximise the LEBT performance. Downstream of the Linac4 accelerator the beam...

High-quality laser-produced proton beam realized by the application of a synchronous RF electric field

International Nuclear Information System (INIS)

Nakamura, Shu; Ikegami, Masahiro; Iwashita, Yoshihisa; Shirai, Toshiyuki; Tongu, Hiromu; Souda, Hikaru; Noda, Akira; Daido, Hiroyuki; Mori, Michiaki; Kado, Masataka; Sagisaka, Akito; Ogura, Koichi; Nishiuchi, Mamiko; Orimo, Satoshi; Hayashi, Yukio; Yogo, Akifumi; Pirozhkov, Alexander S.; Bulanov, Sergei V.; Esirkepov, Timur; Nagashima, Akira; Kimura, Toyoaki; Tajima, Toshiki; Takeuchi, Takeshi; Fukumi, Atsushi; Li, Zhong

2007-01-01

A short-pulse (∼210fs) high-power (∼1 TW) laser was focused on a tape target 3 and 5 μm in thickness to a size of 11 x 15 μm 2 with an intensity of 3 x 10 17 W/cm 2 . Protons produced by this laser with an energy spread of 100% were found to be improved to create peaks in the energy distribution with a spread of ∼7% by the application of the RF electric field with an amplitude of ±40kV synchronous to the pulsed laser. This scheme combines the conventional RF acceleration technique with laser-produced protons for the first time. It is possible to be operated up to 10 Hz, and is found to have good reproducibility for every laser shot with the capability of adjusting the peak positions by control of the relative phase between the pulsed laser and the RF electric field. (author)

First beam in Linac4 DTL

CERN Multimedia

Katarina Anthony

2014-01-01

Following the installation of the Linac4 Drift Tube Linac (DTL) earlier this summer (see here), the first DTL tank saw beams at 12 MeV on 5 August.   Transverse emittance measured at 12 MeV after the DTL tank1 using a temporary slit-and-grid emittance device. You never forget your first beam. That was especially true for the Linac4 DTL team, as it followed years of design, construction and vigorous testing. "We performed countless measurements of the geometry, vacuum and magnet polarisation of the DTL tanks while we were in the workshop," says Suitbert Ramberger, project engineer for the Linac4 DTL. "Add that preparation to the excellent RF conditioning that we carried out in the weeks before the beam tests and I was confident that the acceleration with beam would fully meet expectations!" Indeed it did. Beam commissioning tests ran until 21 August and found the DTL operating with nominal transmission. This successful run has confirmed the innovative design ...

Linac technology for free-electron lasers

International Nuclear Information System (INIS)

Cooper, R.K.; Morton, P.L.; Wilson, P.B.; Keefe, D.; Faltens, A.

1983-01-01

The purpose of this paper is to concentrate on the properties of high-energy electron linear accelerators for use in free-electron lasers operating principally in the Compton regime. To fix our focus somewhat, we shall consider electron energies in the 20- to 200-MeV range and consider requirements for high-power free-electron lasers operating in the 0.5- to 10-μm range. Preliminary remarks are made on high-power free-electron laser amplifiers and oscillators and some desirable characteristics of the linacs that deliver electron beams for these devices. Both the high peak-current requirements of the amplifier and the high pulse-repetition frequency requirements of the oscillator can be met by present-day linac technology, although not necessarily by the same machine. In this papers second and third section, the technology of two rather different types of linear accelerators, the rf linac and the induction linac, is reviewed. In conclusion, applications to the Free Electron Lasers are stated

ANU LINAC upgrade using multi-stub resonators

Indian Academy of Sciences (India)

LINAC development work at ANU is currently aimed at improving ... current through the rf joint at the base of the outer wall and so increasing joint losses. The ... The stub geometry was developed with a help of Superfish/Poisson software [8].

Achieving 99.9% proton spin-flip efficiency at higher energy with a small rf dipole

CERN Document Server

Leonova, M A; Gebel, R; Hinterberger, F; Krisch, A D; Lehrach, A; Lorentz, B; Maier, R; Morozov, V S; Prasuhn, D; Raymond, R S; Schnase, A; Stockhorst, H; Ulbrich, K; Wong, V K; 10.1103/PhysRevLett.93.224801

2004-01-01

We recently used a new ferrite rf dipole to study spin flipping of a 2.1 GeV/c vertically polarized proton beam stored in the COSY Cooler Synchrotron in Julich, Germany. We swept the rf dipole's frequency through an rf-induced spin resonance to flip the beam's polarization direction. After determining the resonance's frequency, we varied the frequency range, frequency ramp time, and number of flips. At the rf dipole's maximum strength and optimum frequency range and ramp time, we measured a spin-flip efficiency of 99.92+or-0.04%. This result, along with a similar 0.49 GeV/c IUCF result, indicates that, due to the Lorentz invariance of an rf dipole's transverse integral Bdl and the weak energy dependence of its spin-resonance strength, an only 35% stronger rf dipole should allow efficient spin flipping in the 100 GeV BNL RHIC Collider or even the 7 TeV CERN Large Hadron Collider.

Basis for low beam loss in the high-current APT linac

International Nuclear Information System (INIS)

Wangler, T.P.; Gray, E.R.; Krawczyk, F.L.; Kurennoy, S.S.; Lawrence, G.P.; Ryne, R.D.; Crandall, K.R.

1998-01-01

The present evidence that the APT proton linac design will meet its goal of low beam loss operation. The conclusion has three main bases: (1) extrapolation from the understanding of the performance of the 800-MeV LANSCE proton linac at Los Alamos, (2) the theoretical understanding of the dominant halo-forming mechanism in the APT accelerator from physics models and multiparticle simulations, and (3) the conservative approach and key principles underlying the design of the APT linac, which are aimed at minimizing beam halo and providing large apertures to reduce beam loss to a very low value

A new method for improving beam quality of LINAC

International Nuclear Information System (INIS)

Xie Jialin; Li Fengtian; Wang Yanshan; Wang Bosi

1999-01-01

The principle of the self-adaptive feed-forward (SAFF) control to improve the beam quality of linac is introduced. the analytical procedure for calculating the control signals, the structure of a practical control system, and applications of SAFF in klystron, RF gun, and linac are presented, especially the application in the thermionic gun whose response is non-linear, time-variant and of large time-delay. The described control system is operational and some primary experimental results have been obtained, including the control of amplitude and phase fluctuations of the klystron output, the microwave field in the gun cavity and linac

The Linac4 DTL Prototype: Low and High Power Measurements

CERN Document Server

De Michele, G; Marques-Balula, J; Ramberger, S

2012-01-01

The prototype of the Linac4 Drift Tube Linac (DTL) has undergone low power measurements in order to verify the RF coupling and to adjust the post-coupler lengths based on bead-pull and spectrum measurements. Following the installation at the test stand, the cavity has been subjected to high power operation at Linac4 and SPL duty cycles. Saturation effects and multipacting have been observed and linked to X-ray emission. Voltage holding is reported in the presence of magnetic fields from permanent magnet quadrupoles (PMQ) installed in the first drift tubes.

Oxygen ion source and RFQ for Linac 1

CERN Multimedia

Photographic Service

1986-01-01

As injector to the PS Booster, Linac 1 was replaced by Linac 2 in 1980. It continued to be used for the acceleration of oxygen and sulfur ions. In 1984, its Cockcroft-Walton preinjector was replaced by an RFQ. In the foreground at the right is the oxygen ion source. A 90 deg bending magnet selects O6+ ions which are preaccelerated in an RFQ and enter Linac 1, at the far left. In the background is the proton and negative hydrogen ion source, followed by the 520 keV RFQ-1 and a bending magnet towards the entrance of Linac 1.

EG and G electron linac modifications

International Nuclear Information System (INIS)

Norris, N.J.; Detch, J.L.; Kocimski, S.M.; Sawyer, C.R.; Hudson, C.L.

1986-01-01

A three-year modification of the EG and G electron linac has been performed to replace obsolete equipment and bring all subsystems up to the current state of the art. Components and subsystems were designed, constructed, and tested off-line to minimize interruption of experiments. The configuration of the modified linac is shown schematically, and performance characteristics are give. Each subsystem is described, including: the electron gun; solenoid focusing system; subharmonic bunchers; accelerating system; RF system; klystron modulators and power supplies; control system; beam handling system; vacuum system; and beam current monitors. 7 refs., 4 figs., 2 tabs

Physics design of a 10 MeV, 6 kW travelling wave electron linac for ...

Indian Academy of Sciences (India)

2016-10-11

Oct 11, 2016 ... We present the physics design of a 10 MeV, 6 kW S-band (2856 MHz) electron linear ... linac (in contrast with standing wave linac) is that it accepts the RF power over a band of frequencies. Three- ... structures are preferred for relatively higher energy ... klystron in a TW linac, which results in cost reduction.

The KAERI 10 MeV Electron Linac - Description and Operational Manual

Energy Technology Data Exchange (ETDEWEB)

Lee, Byung Cheol; Park, Seong Hee; Jung, Young Uk; Han, Young Hwan; Kang, Hee Young

2005-06-15

The objective of this technical report is to guide the right operation and maintenance of the KAERI electron linac system. The KAERI electron linac system consists of 2 MeV injector based on 176 MHz Normal conducting RF (Radio Frequency)cavity and 10 MeV main accelerator based on 352 MHz Superconducting RF cavity, electron beamlines (injection and extraction). Since a electron accelerator generates hazard radiation, this system is located at the shielded room in basement and we can operate the system using the remote control system. It includes the description and the operational manual as well as the detailed technical direction for trouble shooting.

The KAERI 10 MeV Electron Linac - Description and Operational Manual

International Nuclear Information System (INIS)

Lee, Byung Cheol; Park, Seong Hee; Jung, Young Uk; Han, Young Hwan; Kang, Hee Young

2005-06-01

The objective of this technical report is to guide the right operation and maintenance of the KAERI electron linac system. The KAERI electron linac system consists of 2 MeV injector based on 176 MHz Normal conducting RF (Radio Frequency)cavity and 10 MeV main accelerator based on 352 MHz Superconducting RF cavity, electron beamlines (injection and extraction). Since a electron accelerator generates hazard radiation, this system is located at the shielded room in basement and we can operate the system using the remote control system. It includes the description and the operational manual as well as the detailed technical direction for trouble shooting

Measurement of the longitudinal wakefield and the bunch shape in the SLAC linac

International Nuclear Information System (INIS)

Bane, K.L.F.; Decker, F.J.; Seeman, J.T.; Zimmermann, F.

1997-05-01

The authors report on measurements of the bunch energy spectrum at the end of the SLAC linac. Using the spectra obtained for two different linac rf phases they obtain both the bunch induced voltage and the longitudinal distribution of the bunch. The measurement results are compared with theoretical predictions. In particular, the induced voltage is in good agreement with that obtained using the calculated wake function for the SLAC linac. This measurement technique may be useful for monitoring changes of the linac bunch shape in the SLC

RF-Based Accelerators for HEDP Research

CERN Document Server

Staples, John W; Keller, Roderich; Ostroumov, Peter; Sessler, Andrew M

2005-01-01

Accelerator-driven High-Energy Density Physics experiments require typically 1 nanosecond, 1 microcoulomb pulses of mass 20 ions accelerated to several MeV to produce eV-level excitations in thin targets, the "warm dense matter" regime. Traditionally the province of induction linacs, RF-based acceleration may be a viable alternative with recent breakthroughs in accelerating structures and high-field superconducting solenoids. A reference design for an RF-based accelerator for HEDP research is presented using 15 T solenoids and multiple-gap RF structures configured with either multiple parallel beams (combined at the target) or a single beam and a small stacking ring that accumulates 1 microcoulomb of charge. In either case, the beam is ballistically compressed with an induction linac core providing the necessary energy sweep and injected into a plasma-neutralized drift compression channel resulting in a 1 mm radius beam spot 1 nanosecond long at a thin foil or low-density target.

Experience with a radio frequency gun on the SSRL Injector Linac

International Nuclear Information System (INIS)

Weaver, J.N.; Genin, R.D.; Golceff, P.; Morales, H.; Sebek, J.

1993-04-01

A-SSRL/Varian-Associates-built, one-and-a-half cavity microwave, thermionic-cathode gun has operated on the SSRL Injector Linac reliably without changing the cathode for over 10,000 hours, with no significant decrease in emission. Thus, for a pulsed electron beam, with a maximum of 0.5 A peak at 2 to 3 MeV from a 3.5 MW peak rf pulse of 2 μs pulse width at 10 pps, the apparent but small amount of back bombardment of the cathode has been tolerable. Use of a bunch-compression alpha magnet and a stripline chopper after the gun produces the required S-band 3 to 5 microbunches of electrons for injection into a standard 10-m-long linac and on into a booster synchrotron, which in turn is used to fill SPEAR. Component limitations and operating characteristics of the gun and the linac's rf system are discussed

Optical modeling of induction-linac driven free-electron lasers

International Nuclear Information System (INIS)

Scharlemann, E.T.; Fawley, W.M.

1986-01-01

The free-electron laser (FEL) simulation code FRED, developed at Lawrence Livermore National Laboratory (LLNL) primarily to model single-pass FEL amplifiers driven by induction linear accelerators, is described. The main emphasis is on the modeling of optical propagation in the laser and on the differences between the requirements for modeling rf-linac-driven vs. induction-linac-driven FELs. Examples of optical guiding and mode cleanup are presented for a 50 μm FEL

Rf System for the NLCTA

International Nuclear Information System (INIS)

Wang, J.W.; Adolphsen, C.; Eichner, J.; Fuller, R.W.; Gold, S.L.; Hanna, S.M.; Hoag, H.A.; Holmes, S.G.; Koontz, R.F.; Lavine, Theodore L.; Loewen, R.J.; Miller, R.H.; Nantista, C.D.; Pope, R.; Rifkin, J.; Ruth, R.D.; Tantawi, S.G.; Vlieks, A.E.; Wilson, Z.; Yeremian, A.

2011-01-01

This paper describes an X-Band RF system for the Next Linear Collider Test Accelerator. The RF system consists of a 90 MeV injector and a 540 MeV linac. The main components of the injector are two low-Q single-cavity prebunchers and two 0.9-m-long detuned accelerator sections. The linac system consists of six 1.8-m-long detuned and damped detuned accelerator sections powered in pairs. The rf power generation, compression, delivery, distribution and measurement systems consist of klystrons, SLEDII energy compression systems, rectangular waveguides, magic-T's, and directional couplers. The phase and amplitude for each prebuncher is adjusted via a magic-T type phase shifter/attenuator. Correct phasing between the two 0.9 m accelerator sections is obtained by properly aligning the sections and adjusting two squeeze type phase shifters. Bunch phase and bunch length can be monitored with special microwave cavities and measurement systems. The design, fabrication, microwave measurement, calibration, and operation of the sub-systems and their components are briefly presented.

Progress in the Development of the TOP Linac

CERN Document Server

Picardi, L

2004-01-01

The TOP Linac (Oncological Therapy with Protons), under development by ENEA and ISS is a sequence of three pulsed (5 msec, 300 Hz) linear accelerators: a 7 MeV, 425 MHz RFQ+DTL (AccSys Model PL-7), a 7–65 MeV, 2998 MHz Side Coupled Drift Tube Linac (SCDTL) and a 65–200 MeV, variable energy 2998 MHz Side Coupled Linac (SCL). The first SCDTL module is composed by 11 DTL tanks coupled by 10 side cavities. The tanks has modified to overcome vacuum leakage that occurred during brazing, and now the module has been completed, and is ready to be tested with protons. The 7 MeV injector has been recently installed in the ENEA Frascati laboratories for preliminary test, before being transferred to the main Oncologycal Hospital in Rome, Istituto Regina Elena.

Fermilab: Linac upgrade

International Nuclear Information System (INIS)

Anon.

1990-01-01

The Fermilab linear accelerator (Linac) was conceived 20 years ago, produced its first 200 MeV proton beam on 30 November 1970 and has run without major interruption ever since. Demands have steadily increased through the added complexity of the downstream chain of accelerators and by the increased patient load of the Neutron Therapy Facility

RF cavity evaluation with the code SUPERFISH

International Nuclear Information System (INIS)

Hori, T.; Nakanishi, T.; Ueda, N.

1982-01-01

The computer code SUPERFISH calculates axisymmetric rf fields and is most applicable to re-entrant cavities of an Alvarez linac. Some sample results are shown for the first Alvarez's in NUMATRON project. On the other hand the code can also be effectivily applied to TE modes excited in an RFQ linac when the cavity is approximately considered as positioning at an infinite distance from the symmetry axis. The evaluation was made for several RFQ cavities, models I, II and a test linac named LITL, and useful results for the resonator design were obtained. (author)

Some aspects of linacs as applied to the ISL benchmark facility

International Nuclear Information System (INIS)

Shepard, K.W.

1992-01-01

This paper considers several aspects of using linacs in a radioactive beam facility in terms of the Isospin Laboratory (ISL) Benchmark Facility (BMF) plan, described in the 1991 white paper for a possible radioactive-beam laboratory. The intention is not to review comprehensively the application of linacs to an ISL facility, but to compare in outline form several linac options for such a facility. Particular emphasis is given to the use of superconducting rf technology for the secondary beam accelerator. In what follows, first a possible normally-conducting light-ion linac for a primary beam accelerator is briefly outlined. Then the performance and cost of two options for a secondary beam accelerator are compared: a recent design for a normal-conducting cw linac, and an ATLAS-type superconducting linac. Finally, some of the problems which may be encountered at the entrance of a secondary beam linac are discussed

Hospital-based proton linear accelerator for particle therapy and radioisotope production

Science.gov (United States)

Lennox, Arlene J.

1991-05-01

Taking advantage of recent advances in linear accelerator technology, it is possible for a hospital to use a 70 MeV proton linac for fast neutron therapy, boron neutron capture therapy, proton therapy for ocular melanomas, and production of radiopharmaceuticals. The linac can also inject protons into a synchrotron for proton therapy of deep-seated tumors. With 180 μA average current, a single linac can support all these applications. This paper presents a conceptual design for a medical proton linac, switchyard, treatment rooms, and isotope production rooms. Special requirements for each application are outlined and a layout for sharing beam among the applications is suggested.

High total dose proton irradiation effects on silicon NPN rf power transistors

International Nuclear Information System (INIS)

Bharathi, M. N.; Praveen, K. C.; Prakash, A. P. Gnana; Pushpa, N.

2014-01-01

The effects of 3 MeV proton irradiation on the I-V characteristics of NPN rf power transistors were studied in the dose range of 100 Krad to 100 Mrad. The different electrical characteristics like Gummel, current gain and output characteristics were systematically studied before and after irradiation. The recovery in the I-V characteristics of irradiated NPN BJTs were studied by isochronal and isothermal annealing methods

High total dose proton irradiation effects on silicon NPN rf power transistors

Energy Technology Data Exchange (ETDEWEB)

Bharathi, M. N.; Praveen, K. C.; Prakash, A. P. Gnana, E-mail: gnanaprakash@physics.uni-mysore.ac.in [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore-570006, Karnataka (India); Pushpa, N. [Department of PG Studies in Physics, JSS College, Ooty Road, Mysore-570025, Karnataka (India)

2014-04-24

The effects of 3 MeV proton irradiation on the I-V characteristics of NPN rf power transistors were studied in the dose range of 100 Krad to 100 Mrad. The different electrical characteristics like Gummel, current gain and output characteristics were systematically studied before and after irradiation. The recovery in the I-V characteristics of irradiated NPN BJTs were studied by isochronal and isothermal annealing methods.

Emittance reconstruction technique for the Linac4 high energy commissioning

CERN Document Server

Lallement, JB; Posocco, PA

2012-01-01

Linac4 is a new 160 MeV linear accelerator for negative Hydrogen ions (H-) presently under construction which will replace the 50 MeV proton Linac2 as injector for the CERN proton accelerator complex. Linac4 is 80 meters long and comprises a Low Energy Beam Transport line, a 3 MeV RFQ, a MEBT, a 50 MeV DTL, a 100 MeV CCDTL and a PIMS up to 160 MeV. The commissioning of the Linac is scheduled to start in 2013. It will be divided into several steps corresponding to the commissioning of the different accelerating structures. A temporary measurement bench will be dedicated to the high energy commissioning from 30 to 100 MeV (DTL tanks 2 and 3, and CCDTL). The commissioning of the PIMS will be done using the permanent equipment installed in between the end of the Linac and the main dump. This note describes the technique we will use for reconstructing the transverse emittances and the expected results.

200 MeV RF linac for synchrotron injection

International Nuclear Information System (INIS)

Whitham, K.; Anamkath, H.; Lyons, S.; Manca, J.; Miller, R.; Treas, P.; Zante, T.; Miller, R.

1992-01-01

Construction has been completed on an electron linear accelerator for the Brookhaven National Laboratory. This accelerator will be used for the injection of a 200 MeV electron beam into a synchrotron for lithography experiments. This paper describes the conceptual design of the linac, its e-gun pulser, and its control and timing systems. 3 figs., ref

Microbunching and RF Compression

International Nuclear Information System (INIS)

Venturini, M.; Migliorati, M.; Ronsivalle, C.; Ferrario, M.; Vaccarezza, C.

2010-01-01

Velocity bunching (or RF compression) represents a promising technique complementary to magnetic compression to achieve the high peak current required in the linac drivers for FELs. Here we report on recent progress aimed at characterizing the RF compression from the point of view of the microbunching instability. We emphasize the development of a linear theory for the gain function of the instability and its validation against macroparticle simulations that represents a useful tool in the evaluation of the compression schemes for FEL sources.

Analysis of the FEL-RF interaction in recirculating, energy-recovering linacs with an FEL

International Nuclear Information System (INIS)

Merminga, L.; Alexeev, P.; Benson, S.; Bolshakov, A.; Doolittle, L.; Neil, G.

1999-01-01

Recirculating, energy-recovering linacs can be used as driver accelerators for high power FELs. Instabilities which arise from fluctuations of the cavity fields are investigated. Energy changes can cause beam loss on apertures, phase oscillations and optical cavity detuning. These effects in turn cause changes in the laser output power through a time-varying FEL gain function. All three effects change the beam-induced voltage in the cavities and can lead to unstable variations of the accelerating field and output laser power. We have developed a model of the coupled system and solved it both analytically and numerically. It includes the beam-cavity interaction, low level RF feedback, and the electron-photon interaction. The latter includes the FEL gain function in terms of cavity detuning, energy offset, and is valid both in the small signal gain and in the saturated regimes. We have demonstrated that in the limit of small perturbations, the linear theory agrees with the numerical solutions and have performed numerical simulations for the IR FEL presently being commissioned at Jefferson Lab

Analysis of the FEL-RF interaction in recirculating energy-recovering linacs with an FEL

International Nuclear Information System (INIS)

Merminga, Lia; Alexeev, P.; Benson, Steve; Bolshakov, A.; Doolittle, Lawrence; Neil, George

1999-01-01

Recirculating, energy-recovering linacs can be used as driver accelerators for high power FELs. Instabilities which arise from fluctuations of the cavity fields are investigated. Energy changes can cause beam loss on apertures, phase oscillations and optical cavity detuning. These effects in turn cause changes in the laser output power through a time-varying FEL gain function. All three effects change the beam-induced voltage in the cavities and can lead to unstable variations of the accelerating field and output laser power. We have developed a model of the coupled system and solved it both analytically and numerically. It includes the beam-cavity interaction, low level RF feedback, and the electron-photon interaction. The latter includes the FEL gain function in terms of cavity detuning, energy offset, and is valid both in the small signal gain and in the saturated regimes. We have demonstrated that in the limit of small perturbations, the linear theory agrees with the numerical solutions and have performed numerical simulations for the IR FEL presently being commissioned at Jefferson Lab

Analysis of the FEL-RF interaction in recirculating, energy-recovering linacs with an FEL

Energy Technology Data Exchange (ETDEWEB)

Merminga, L. E-mail: merminga@jlab.org; Alexeev, P.; Benson, S.; Bolshakov, A.; Doolittle, L.; Neil, G

1999-06-01

Recirculating, energy-recovering linacs can be used as driver accelerators for high power FELs. Instabilities which arise from fluctuations of the cavity fields are investigated. Energy changes can cause beam loss on apertures, phase oscillations and optical cavity detuning. These effects in turn cause changes in the laser output power through a time-varying FEL gain function. All three effects change the beam-induced voltage in the cavities and can lead to unstable variations of the accelerating field and output laser power. We have developed a model of the coupled system and solved it both analytically and numerically. It includes the beam-cavity interaction, low level RF feedback, and the electron-photon interaction. The latter includes the FEL gain function in terms of cavity detuning, energy offset, and is valid both in the small signal gain and in the saturated regimes. We have demonstrated that in the limit of small perturbations, the linear theory agrees with the numerical solutions and have performed numerical simulations for the IR FEL presently being commissioned at Jefferson Lab.

The design of a radio frequency quadrupole LINAC for the RIB ...

Indian Academy of Sciences (India)

Logo of the Indian Academy of Sciences. Indian Academy of Sciences ... Physics; Volume 59; Issue 6. The design of a radio frequency quadrupole LINAC for the RIB project at VECC Kolkata ... rf structure design study. The beam dynamics and rf-structure design along with the results of the cold model tests will be presented.

Beam dynamics of alternating-phase-focused linac

CERN Document Server

Iwata, Y; Kapin, V

2004-01-01

A simple method to find an array of synchronous phases for alternating-phase-focused (APF) linacs is presented. The phase array is described with a smooth function having free parameters. With a set of the parameters, a simulation on the beam dynamics was made and distributions of the six-dimensional phase spaces were calculated for each set of the parameters. The parameters were varied, and numbers of the simulations have been performed. An optimum set of the parameters were determined so that the simulations of the beam dynamics yield large acceptances and small emittances of the extracted beams. Since the APF linac can provide both axial and radial stability of beams just with the rf acceleration-field, no additional focusing element inside of drift tubes are necessary. Comparing with conventional linacs having focusing elements, it has advantage in construction and operation costs as well as its acceleration rate. Therefore, the APF linacs would be suited for an injector of medical synchrotrons. A practic...

A proposed injector for the LCLS linac

International Nuclear Information System (INIS)

Yeremian, A.D.; Bharadwaj, V.K.; Emma, P.; Miller, R.H.; Palmer, D.T.; Woodley, M.D.

1996-11-01

The Linac Coherent Light Source (LCLS) will use the last portion of the SLAC accelerator as a driver for a short wavelength FEL. The injector must produce 1-nC, 3-ps rms electron bunches at a repetition rate of up to 120 Hz with a normalized rms emittance of about 1 mm-mrad. The injector design takes advantage of the photocathode rf gun technology developed since its conception in the mid 1980's, in particular the S-band rf gun developed by the SLAC/BNL/UCLA collaboration, and emittance compensation techniques developed in the last decade. The injector beamline has been designed using the SUPERFISH, POISSON, PARMELA, and TRANSPORT codes in a consistent way to simulate the beam from the gun up to the entrance of the main accelerator linac where the beam energy is 150 MeV. PARMELA simulations indicate that at 150 MeV, space charge effects are negligible

Home made FPGA based instrumentation development for linac automation at IUAC

International Nuclear Information System (INIS)

Antony, J.; Mathuria, D.S.; Sacharias, J.

2011-01-01

In order to make the Inter-University Accelerator Centre (IUAC) linac operation with less human intervention and with minimum effort, different mechanisms of automation are being thought of and are being implemented. Among the various projects in the automation, the first one is the development of a 16-channel digital linearizer unit for RF power read-backs and control. In another development, 8 channel programmable pulse generators (PPG) were designed, developed and used at the time of RF pulse conditioning of the SC resonators. As a third project of linac automation, a computer controlled drive probe controller was developed to control the movement of 8 drive couplers of the resonator along with position sensor read back mechanisms. (author)

Development of 650 MHz solid state RF amplifier for proton accelerator

International Nuclear Information System (INIS)

Jain, Akhilesh; Sharma, Deepak; Gupta, Alok; Tiwari, Ashish; Rao, Nageswar; Sekar, Vasanthi; Lad, M.; Hannurkar, P.R.; Gupta, P.D.

2011-01-01

Design and development of 30 kW high powers RF source at 650 MHz, using solid RF state technology, has been initiated at RRCAT. The indigenous technology development efforts will be useful for the proposed high power proton accelerators for SNS/ADS applications. In this 650 MHz amplifier scheme, 30 kW CW RF power will be generated using modular combination of 8 kW amplifier units. Necessary studies were carried out for device selection, choice of amplifier architecture and design of high power combiners and dividers. Presently RF amplifier delivering 250 W at 650 MHz has been fabricated and tested. Towards development of high power RF components, design and engineering prototyping of 16-port power combiner, directional coupler and RF dummy loads has been completed. The basic 8 kW amplifier unit is designed to provide power gain of 50 dB, bandwidth of 20 MHz and spurious response below 30 dB from fundamental signal. Based on the results of circuit simulation studies and engineering prototyping of amplifier module, two RF transistor viz. MRF3450 and MRF 61K were selected as solid state active devices. Impedance matching network in amplifier module is designed using balanced push pull configuration with transmission line BALUN. Due to high circulating current near drain side, metal clad RF capacitors were selected which helps in avoiding hot spot from output transmission path, ensuring continuous operation at rated RF power without damage to RF board. 350 W circulator is used to protect the RF devices from reflected power. Based on the prototype design and measured performance, one of these RF transistors will be selected to be used as workhorse for all amplifier modules. Two amplifier modules are mounted on water cooled copper heat-sink ensuring proper operating temperature for reliable and safe operation of amplifier. Also real time control system and data logger has been developed to provide DAQ and controls in each rack. For power combining and power measurement

Experimental studies of emittance growth and energy spread in a photocathode RF gun

International Nuclear Information System (INIS)

Yang, J.; Sakai, F.; Okada, Y.; Yorozu, M.; Yanagida, T.; Endo, A.

2002-01-01

In this paper we report on a low emittance electron source, based on a photocathode RF gun, a solenoid magnet and a subsequent linac. The dependencies of the beam transverse emittance and relative energy spread with respect to the laser injection phase of the radio-frequency (RF) gun, the RF phase of the linac and the bunch charge were investigated experimentally. It was found that a lower beam emittance is observed when the laser injection phase in the RF gun is low. The emittance increases almost linearly with the bunch charge under a constant solenoid magnetic field. The corrected relative energy spread of the beam is not strongly dependent on the bunch charge. Finally, an optimal normalized rms transverse emittance of 1.91±0.28 πmm mrad at a bunch charge of 0.6 nC was obtained when the RF gun was driven by a picosecond Nd:YAG laser. A corrected relative rms energy spread of 0.2-0.25% at a bunch charge of 0.3-2 nC was obtained after the beam was accelerated to 14 MeV by the subsequent linac

Experimental studies of emittance growth and energy spread in a photocathode RF gun

CERN Document Server

Yang, J; Okada, Y; Yorozu, M; Yanagida, T; Endo, A

2002-01-01

In this paper we report on a low emittance electron source, based on a photocathode RF gun, a solenoid magnet and a subsequent linac. The dependencies of the beam transverse emittance and relative energy spread with respect to the laser injection phase of the radio-frequency (RF) gun, the RF phase of the linac and the bunch charge were investigated experimentally. It was found that a lower beam emittance is observed when the laser injection phase in the RF gun is low. The emittance increases almost linearly with the bunch charge under a constant solenoid magnetic field. The corrected relative energy spread of the beam is not strongly dependent on the bunch charge. Finally, an optimal normalized rms transverse emittance of 1.91+-0.28 pi mm mrad at a bunch charge of 0.6 nC was obtained when the RF gun was driven by a picosecond Nd:YAG laser. A corrected relative rms energy spread of 0.2-0.25% at a bunch charge of 0.3-2 nC was obtained after the beam was accelerated to 14 MeV by the subsequent linac.

Commissioning of the 112 MHz SRF Gun and 500 MHz bunching cavities for the CeC PoP Linac

Energy Technology Data Exchange (ETDEWEB)

Belomestnykh, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., NY (United States); Ben-Zvi, I. [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., NY (United States); Brutus, J. C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Litvinenko, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., NY (United States); McIntosh, P. [Science and Technology Facilities Council (STFC), Daresbury (United Kingdom). Daresbury Lab.; Moss, A. [Science and Technology Facilities Council (STFC), Daresbury (United Kingdom). Daresbury Lab.; Narayan, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Orfin, P. [Brookhaven National Lab. (BNL), Upton, NY (United States); Pinayev, I. [Brookhaven National Lab. (BNL), Upton, NY (United States); Rao, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Skaritka, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Smith, K. [Brookhaven National Lab. (BNL), Upton, NY (United States); Than, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tuozzolo, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wang, E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wheelhouse, A. [Science and Technology Facilities Council (STFC), Daresbury (United Kingdom). Daresbury Lab.; Wu, Q. [Brookhaven National Lab. (BNL), Upton, NY (United States); Xiao, B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Xin, T. [Stony Brook Univ., NY (United States); Xu, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zaltsman, A. [Brookhaven National Lab. (BNL), Upton, NY (United States)

2015-05-03

The Coherent electron Cooling Proof-of-Principle (CeC PoP) experiment at BNL includes a short electron linac. During Phase 1, a 112 MHz superconducting RF photo-emission gun and two 500 MHz normal conducting bunching cavities were installed and are under commissioning. The paper describes the Phase1 linac layout and presents commissioning results for the cavities and associated RF, cryogenic and other sub-systems

Development of Infrastructure Facilities for Superconducting RF Cavity Fabrication, Processing and 2 K Characterization at RRCAT

Science.gov (United States)

Joshi, S. C.; Raghavendra, S.; Jain, V. K.; Puntambekar, A.; Khare, P.; Dwivedi, J.; Mundra, G.; Kush, P. K.; Shrivastava, P.; Lad, M.; Gupta, P. D.

2017-02-01

An extensive infrastructure facility is being established at Raja Ramanna Centre for Advanced Technology (RRCAT) for a proposed 1 GeV, high intensity superconducting proton linac for Indian Spallation Neutron Source. The proton linac will comprise of a large number of superconducting Radio Frequency (SCRF) cavities ranging from low beta spoke resonators to medium and high beta multi-cell elliptical cavities at different RF frequencies. Infrastructure facilities for SCRF cavity fabrication, processing and performance characterization at 2 K are setup to take-up manufacturing of large number of cavities required for future projects of Department of Atomic Energy (DAE). RRCAT is also participating in a DAE’s approved mega project on “Physics and Advanced technology for High intensity Proton Accelerators” under Indian Institutions-Fermilab Collaboration (IIFC). In the R&D phase of IIFC program, a number of high beta, fully dressed multi-cell elliptical SCRF cavities will be developed in collaboration with Fermilab. A dedicated facility for SCRF cavity fabrication, tuning and processing is set up. SCRF cavities developed will be characterized at 2K using a vertical test stand facility, which is already commissioned. A Horizontal Test Stand facility has also been designed and under development for testing a dressed multi-cell SCRF cavity at 2K. The paper presents the infrastructure facilities setup at RRCAT for SCRF cavity fabrication, processing and testing at 2K.

Signal multiplexing scheme for LINAC

International Nuclear Information System (INIS)

Sujo, C.I.; Mohan, Shyam; Joshi, Gopal; Singh, S.K.; Karande, Jitendra

2004-01-01

For the proper operation of the LINAC some signals, RF (radio frequency) as well as LF (low frequency) have to be available at the Master Control Station (MCS). These signals are needed to control, calibrate and characterize the RF fields in the resonators. This can be achieved by proper multiplexing of various signals locally and then routing the selected signals to the MCS. A multiplexing scheme has been designed and implemented, which will allow the signals from the selected cavity to the MCS. High isolation between channels and low insertion loss for a given signal are important issues while selecting the multiplexing scheme. (author)

Target irradiation facility and targetry development at 160 MeV proton beam of Moscow linac

CERN Document Server

Zhuikov, B L; Konyakhin, N A; Vincent, J

1999-01-01

A facility has been built and successfully operated with the 160 MeV proton beam of Moscow Meson factory LINAC, Institute for Nuclear Research (INR) of Russian Academy of Science, Troitsk. The facility was created for various isotope production goals as well as for fundamental nuclear investigations at high intensity beam (100 mu A and more). An important part of the facility targetry system is a high-intensity beam monitoring collimator device. Measurements of the temperature distribution between collimator sectors, cooling water flow and temperature, and the beam current, provide an opportunity to compute beam losses and beam position. The target holder design allows easy insertion by manipulator and simultaneous bombardment of several different targets of various types and forms, and variation of proton energy on each target over a wide range below 160 MeV. The main target utilized for commercial sup 8 sup 2 Sr isotope production is metallic rubidium in a stainless-steel container. A regular wet chemistry ...

The RF system for the Accelerator Production of Tritium (APT) Low Energy Demonstration Accelerator (LEDA) at Los Alamos

International Nuclear Information System (INIS)

Lynch, M.T.; Rees, D.; Tallerico, P.; Regan, A.

1996-01-01

To develop and demonstrate the crucial front end of the APT accelerator and some of the critical components for APT, Los Alamos is building a CW proton accelerator (LEDA) to provide 100 mA at up to 40 MeV. LEDA will be installed where the SDI-sponsored Ground Test Accelerator was located. The first accelerating structure for LEDA is a 7-MeV RFQ operating at 350 MHz, followed by several stages of a coupled-cavity Drift Tube Linac (CCDTL) operating at 700 MHz. The first stage of LEDA will go to 12 MeV. Higher energies, up to 40 MeV, come later in the program. Three 1.2-MW CW RF systems will be used to power the RFQ. This paper describes the RF systems being assembled for LEDA, including the 350 and 700-MHz klystrons, the High Voltage Power Supplies, transmitters, RF transport, window/coupler assemblies, and controls. Some of the limitations imposed by the schedule and the building itself are addressed

Manufacture and analysis of exciter RF generator for proton cyclotron Decy-13

International Nuclear Information System (INIS)

Prajitno

2011-01-01

Exciter of the RF generator for 13 MeV proton cyclotron have been analyzed and manufactured. RF generator will be used as a source of alternating voltage accelerating of the Decy-13 cyclotron which designed by PTAPB-BATAN. Based on the basic design documents that have been made, the Decy-13 cyclotron will use 1.275 Tesla magnetic field so that the RF generator frequency when using the fourth harmonic is 77.667 MHz. One of the radio frequency signal generation technique where the output frequency is very stable and easy to set up and is currently being developed is the technique of Direct Digital Synthesizer (DDS). DDS technology is an innovative circuit architecture that allows fast and precise frequency manipulation of its output, under full digital control. Prototype of the RF generator exciter that was created using DDS type AD9851 manufactured by Analog Devices with a fundamental frequency of 30 MHz and controlled by the ATmega16 micro controller. To avoid unexpected frequency of its output, the output signal of the DDS is passed to the passive band pass filter circuit. The test results showed that the exciter output frequency range is 2 MHz with center frequency of 77.667 MHz. and stop band -3 dB. While RF power output 10 Watt require 12 V power supply with current 1,6 A. Although the exciter prototype still needs improvement but the results are as expected. (author)

Design of an L-band normally conducting RF gun cavity for high peak and average RF power

Energy Technology Data Exchange (ETDEWEB)

Paramonov, V., E-mail: paramono@inr.ru [Institute for Nuclear Research of Russian Academy of Sciences, 60-th October Anniversary prospect 7a, 117312 Moscow (Russian Federation); Philipp, S. [Deutsches Elektronen-Synchrotron DESY, Platanenallee 6, D-15738 Zeuthen (Germany); Rybakov, I.; Skassyrskaya, A. [Institute for Nuclear Research of Russian Academy of Sciences, 60-th October Anniversary prospect 7a, 117312 Moscow (Russian Federation); Stephan, F. [Deutsches Elektronen-Synchrotron DESY, Platanenallee 6, D-15738 Zeuthen (Germany)

2017-05-11

To provide high quality electron bunches for linear accelerators used in free electron lasers and particle colliders, RF gun cavities operate with extreme electric fields, resulting in a high pulsed RF power. The main L-band superconducting linacs of such facilities also require a long RF pulse length, resulting in a high average dissipated RF power in the gun cavity. The newly developed cavity based on the proven advantages of the existing DESY RF gun cavities, underwent significant changes. The shape of the cells is optimized to reduce the maximal surface electric field and RF loss power. Furthermore, the cavity is equipped with an RF probe to measure the field amplitude and phase. The elaborated cooling circuit design results in a lower temperature rise on the cavity RF surface and permits higher dissipated RF power. The paper presents the main solutions and results of the cavity design.

SPL-based Proton Driver for a nu-Factory at CERN

CERN Document Server

Benedetto, E; Garoby, R; Meddahi, M

2010-01-01

The conceptual design and feasibility studies for a nu-Factory Proton Driver based on the CERN Superconducting Proton Linac (SPL) have been com- pleted. In the proposed scenario, the 4 MW proton beam (H- beam) is acceler- ated with the upgraded High Power (HP)-SPL to 5 GeV, stored in an accumu- lator ring and Þnally transported to a compressor ring, where bunch rotation takes place, in order to achieve the speciÞc time structure. We here summa- rize the choices in terms of lattice, magnet technology and RF manipulations in the two rings. The possible critical issues, such as heating of the foil for the charge-exchange injection, space-charge problems in the compressor and beam stability in the accumulator ring, have been addressed and are shown not to be show-stoppers. The analysis focuses on the baseline scenario, consider- ing 6 bunches in the accumulator, and preliminary studies are discussed for the option of 3 or a single bunch per burst.

A linac for the Spallation Neutron Source

International Nuclear Information System (INIS)

Jason, A.J.

1998-01-01

The Spallation Neutron Source Project (SNS), to be constructed at Oak Ridge National Laboratory, accelerates H - ions to an energy of 1.0 GeV with an average current of 1-mA for injection into an accumulator ring that produces the short intense burst of protons needed for the spallation-neutron source. The linac will be the most intense source of H - ions and as such requires advanced design techniques to meet project technical goals. In particular, low beam loss is stressed for the chopped beam placing strong requirements on the beam dynamics and linac construction. Additionally, the linac is to be upgraded to the 2- and 4-MW beam-power levels with no increase in duty factor. The author gives an overview of the linac design parameters and design choices made

Heavy-ion acceleration with a superconducting linac

International Nuclear Information System (INIS)

Bollinger, L.M.

1988-01-01

This year, 1988, is the tenth anniversary of the first use of RF superconductivity to accelerate heavy ions. In June 1978, the first two superconducting resonators of the Argonne Tandem-Linac Accelerator System (ATLAS) were used to boost the energy of a 19 F beam from the tandem, and by September 1978 a 5-resonator linac provided an 16 O beam for a nuclear-physics experiment. Since then, the superconducting linac has grown steadily in size and capability until now there are 42 accelerating structures and 4 bunchers. Throughout this period, the system was used routinely for physics research, and by now the total time with beam on target is 35,000 hours. Lessons learned from this long running experience and some key technical developments that made it possible are reviewed in this paper. 19 refs., 3 figs., 2 tabs

rf measurements and tuning of the 750 MHz radio frequency quadrupole

Science.gov (United States)

Koubek, Benjamin; Grudiev, Alexej; Timmins, Marc

2017-08-01

In the framework of the program on medical applications a compact 750 MHz RFQ has been designed and built to be used as an injector for a hadron therapy linac. This RFQ was designed to accelerate protons to an energy of 5 MeV within only 2 m length. It is divided into four segments and equipped with 32 tuners in total. The length of the RFQ corresponds to 5 λ which is considered to be close to the limit for field adjustment using only piston tuners. Moreover the high frequency, which is about double the frequency of existing RFQs, results in a sensitive structure and requires careful tuning. In this paper we present the tuning algorithm, the tuning procedure and rf measurements of the RFQ.

The elbe accelerator facility starts operation with the superconducting rf gun

CERN Document Server

Xiang, R; Buettig, H; Janssen, D; Justus, M; Lehnert, U; Michel, P; Murcek, P; Schneider, C; Schurig, R; Staufenbiel, F; Teichert, J; Kamps, T; Rudolph, J; Schenk, M; Klemz, G; Will, I

2010-01-01

As the first superconducting rf photo-injector (SRF gun) in practice, the FZD 3+1/2 cell SRF gun is successfully connected to the superconducting linac ELBE. This setting will improve the beam quality for ELBE users. It is the first example for an accelerator facility fully based on superconducting RF technology. For high average power FEL and ERL sources, the combination of SRF linac and SRF gun provides a new chance to produce beams of high average current and low emittance with relative low power consumption. The main parameters achieved from the present SRF gun are the final electron energy of 3 MeV, 16 μA average current, and rms transverse normalized emittances of 3 mm mrad at 77 pC bunch charge. A modified 3+1/2 cell niobium cavity has been fabricated and tested, which will increase the rf gradient in the gun and thus better the beam parameters further. In this paper the status of the integration of the SRF gun with the ELBE linac will be presented, and the latest results of the beam experiments will ...

Microphonic measurements on superconducting linac structures

International Nuclear Information System (INIS)

Marzali, A.; Schwettman, H.A.

1992-01-01

Microphonics in multi-cell linac structures lead to energy and pointing modulation of the electron beam despite RF stabilization. Evaluation of the microphonic behaviour of a 500 MHz two cell structure is planned in collaboration with Lawrence Berkeley Laboratory and Brookhaven National Laboratory. In this paper we describe a method of evaluation based on accelerometer measurements. (Author) fig., 2 tabs., 5 refs

Linac4 crosses the 100 MeV threshold

CERN Multimedia

Corinne Pralavorio

2016-01-01

The new linear accelerator, which from 2020 will be the first link in the accelerator chain, has entered a new stage of its commissioning.   Members of the team in charge of the commissioning of Linac4 in the accelerator’s control room. A few hours earlier, Linac4 accelerated a beam to 107 MeV for the first time. We couldn’t have imagined a more appropriate date: on 1 July (1.07), Linac4 reached an energy of 107 MeV. Having crossed the 100 MeV barrier, the linear accelerator is now on the home straight of its commissioning. “This stage was very quick – it took less than two weeks,” says Alessandra Lombardi, deputy project leader of Linac4, in charge of the commissioning. In 2020, Linac4 will replace the existing Linac2 as the first link in the accelerator chain. It will accelerate beams of H- ions (protons surrounded by two electrons) to 160 MeV, compared to 50 MeV with Linac2. The new machine is particularly sophisticated as it comprises...

An improved permanent magnet quadrupole design with larger good field region for high intensity proton linacs

Energy Technology Data Exchange (ETDEWEB)

Mathew, Jose V., E-mail: josev.mathew@gmail.com; Rao, S.V.L.S.; Krishnagopal, S.; Singh, P.

2013-11-01

The Low Energy High Intensity Proton Accelerator (LEHIPA), being developed at the Bhabha Atomic Research Centre (BARC) will produce a 20 MeV, 30 mA, continuous wave (CW) proton beam. At these low velocities, space-charge forces dominate, and could lead to larger beam sizes and beam halos. Hence in the design of the focusing lattice of the LEHIPA drift tube linac (DTL) using permanent magnet quadrupoles (PMQs), a larger good field region is preferred. Here we study, using the two dimensional (2D) and three dimensional (3D) simulation codes PANDIRA and RADIA, four different types of cylindrical PMQ designs: 16-segment trapezoidal Halbach configuration, bullet-nosed geometry and 8- and 16-segment rectangular geometries. The trapezoidal Halbach geometry is used in a variety of accelerators since it provides very high field gradients in small bores, while the bullet-nosed geometry, which is a combination of the trapezoidal and rectangular designs, is used in some DTLs. This study shows that a larger good field region is possible in the 16-segment rectangular design as compared to the Halbach and bullet-nosed designs, making it more attractive for high-intensity proton linacs. An improvement in good-field region by ∼16% over the Halbach design is obtained in the optimized 16-segment rectangular design, although the field gradient is lower by ∼20%. Tolerance studies show that the rectangular segment PMQ design is substantially less sensitive to the easy axis orientation errors and hence will be a better choice for DTLs. -- Highlights: • An improved permanent magnet quadrupole (PMQ) design with larger good field region is proposed. • We investigate four PMQ designs, including the widely used Halbach and bullet nosed designs. • Analytical calculations are backed by 2D as well as 3D numerical solvers, PANDIRA and RADIA. • The optimized 16 segment rectangular PMQ design is identified to exhibit the largest good field region. • The effect of easy axis orientation

An improved permanent magnet quadrupole design with larger good field region for high intensity proton linacs

International Nuclear Information System (INIS)

Mathew, Jose V.; Rao, S.V.L.S.; Krishnagopal, S.; Singh, P.

2013-01-01

The Low Energy High Intensity Proton Accelerator (LEHIPA), being developed at the Bhabha Atomic Research Centre (BARC) will produce a 20 MeV, 30 mA, continuous wave (CW) proton beam. At these low velocities, space-charge forces dominate, and could lead to larger beam sizes and beam halos. Hence in the design of the focusing lattice of the LEHIPA drift tube linac (DTL) using permanent magnet quadrupoles (PMQs), a larger good field region is preferred. Here we study, using the two dimensional (2D) and three dimensional (3D) simulation codes PANDIRA and RADIA, four different types of cylindrical PMQ designs: 16-segment trapezoidal Halbach configuration, bullet-nosed geometry and 8- and 16-segment rectangular geometries. The trapezoidal Halbach geometry is used in a variety of accelerators since it provides very high field gradients in small bores, while the bullet-nosed geometry, which is a combination of the trapezoidal and rectangular designs, is used in some DTLs. This study shows that a larger good field region is possible in the 16-segment rectangular design as compared to the Halbach and bullet-nosed designs, making it more attractive for high-intensity proton linacs. An improvement in good-field region by ∼16% over the Halbach design is obtained in the optimized 16-segment rectangular design, although the field gradient is lower by ∼20%. Tolerance studies show that the rectangular segment PMQ design is substantially less sensitive to the easy axis orientation errors and hence will be a better choice for DTLs. -- Highlights: • An improved permanent magnet quadrupole (PMQ) design with larger good field region is proposed. • We investigate four PMQ designs, including the widely used Halbach and bullet nosed designs. • Analytical calculations are backed by 2D as well as 3D numerical solvers, PANDIRA and RADIA. • The optimized 16 segment rectangular PMQ design is identified to exhibit the largest good field region. • The effect of easy axis orientation

Klystron-modulator system availability of PLS 2 GeV electron linac

International Nuclear Information System (INIS)

Cho, M.H.; Park, S.S.; Oh, J.S.; Namkung, W.

1996-01-01

PLS Linac has been injecting 2 GeV electron beams to the Pohang Light Source (PLS) storage ring since September 1994. PLS 2 GeV linac employs 11 sets of high power klystron-modulator (K and M) system for the main RF source for the beam acceleration. The klystron has rated output peak power of 80 MW at 4 microsec pulse width and at 60 pps. The matching modulator has 200 MW peak output power. The total accumulated high voltage run time of the oldest unit has reached beyond 23,000 hour and the sum of all the high voltage run time is approximately 230,000 hour as of May 1996. In this paper, we review overall system performance of the high-power K and M system. A special attention is paid on the analysis of all failures and troubles of the K and M system which affected the linac high power RF operations as well as beam injection operations for the period of 1994 to May 1996. (author)

RF Beam Position Monitor for the SNS Ring

International Nuclear Information System (INIS)

Vetter, Kurt; Cameron, Peter; Dawson, Craig; Degen, Chris; Kesselman, Martin; Mead, Joseph

2004-01-01

The Spallation Neutron Source Ring accumulates 1060 pulses of 38-mA peak current 1-GeV H-minus particles from the Linac through the HEBT line, then delivers this accumulated beam in a single pulse to a mercury target via the RTBT line. The dynamic range over the course of the accumulation cycle is 60 dB. As a result of particle energy distribution the 402.5-MHz RF bunching frequency quickly de-coheres during the first few turns. In order to measure first-turn position a dual-mode BPM has been designed to process 402.5-MHz signal energy during the first few turns then switch to a Baseband mode to process de-cohered energy in the low MHz region. The design has been implemented as a dual mother/daughter board PCI architecture. Both Baseband and RF calibration are included on the RF BPM board. A prototype system has been installed in the SNS Linac

RF Measurements and Tuning of the 750 MHz HF-RFQ

CERN Document Server

Koubek, Benjamin; Timmins, Marc; CERN. Geneva. ATS Department

2017-01-01

In the frame of the program on medical applications CERN has built a compact 750 MHz RFQ to be used as an injector for a hadron therapy linac. This RFQ was designed to accelerate protons to an energy of 5 {\\lambda} MeV within only 2 m length. It is divided into four segments and equipped with 32 tuners in total. The length of the RFQ corresponds to 5 which is considered to be close to the limit for field adjustment using only piston tuners. Moreover the high frequency, which is about double the frequency of existing RFQs, results in a sensitive structure and requires careful tuning by means of the alignment of the pumping ports and fixed tuners. This report summarises the tuning procedure, RF and bead pull measurements of the RFQ.

Preinjector for Linac 1, accelerating column

CERN Multimedia

1974-01-01

For a description of the Linac 1 preinjector, please see first 7403070X. High up on the wall of the Faraday cage (7403073X) is this drum-shaped container of the ion source (7403083X). It is mounted at the HV end of the accelerating column through which the ions (usually protons; many other types of ions in the course of its long history) proceed through the Faraday cage wall to the low-energy end (at ground potential) of Linac 1. The 520 kV accelerating voltage was supplied by a SAMES generator (7403074X).

Radio frequency quadrupole linac for the superconducting super collider

International Nuclear Information System (INIS)

Schrage, D.L.; Young, L.M.; Clark, W.L.; Billen, J.H.; DePaula, R.F.; Naranjo, A.C.; Neuschaefer, G.H.; Roybal, P.L.; Stovall, J.E.; Ray, K.; Richter, R.

1993-01-01

A 2.5 MeV, 428 MHz radio frequency quadrupole (RFQ) linac has been designed and fabricated by the Los Alamos National Laboratory and GAR Electroforming for the Superconducting Super Collider Laboratory. This device is a two segment accelerator fabricated from tellurium-copper (CDA14500) vane/cavity quadrants which are joined by electroforming. The structure incorporates an integral vacuum jacket and has no longitudinal rf or mechanical joints. The SSC RFQ linac is an extension of the design of the 1.0 MeV RFQ which was successfully flown on the BEAR Project. (orig.)

PIGMI technology

International Nuclear Information System (INIS)

Swenson, D.A.

1980-01-01

The accelerator technologies relevant to the design of a medically practical pion generator for medical irradiations (PIGMI) have been identified and developed. A base-case design for PIGMI is presented here. The accelerator portion of the PIGMI facility consists of an injector, an rf quadrupole linac structure, a drift-tube linac structure, a coupled-cavity linac structure, 1 440-MHz rf system, six 1320-MHz rf systems, and a control and instrumentation system. Each of these components is described in some detail. A 100-μA, 650-MeV proton beam is anticipated. 24 figures, 2 tables

RF windows used at s-band pulsed klystrons in KEK linac

Energy Technology Data Exchange (ETDEWEB)

Michizono, S.; Saito, Y. [KEK, National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)

1997-04-01

The breakdown of the alumina RF-windows used in high-power klystrons is one of the most serious problems in the development of klystrons. This breakdown results from excess heating of alumina due to multipactor bombardments and/or localized RF dissipations. A statistical research of window materials was carried out, and high-power tests were performed in order to develop RF windows having high durability for the KEKB klystrons. The breakdown mechanism of RF windows is being considered. An improved RF window installed in a KEKB klystron is also being tested. (J.P.N)

A High Current Proton Linac with 352 MHz SC Cavities

CERN Document Server

Pagani, C; Pierini, P

1996-01-01

A proposal for a 10-120 mA proton linac employing superconducting beta-graded, CERN type, four cell cavities at 352 MHz is presented. The high energy part (100 MeV-1 GeV) of the machine is split in three beta-graded sections, and transverse focusing is provided via a periodic doublet array. All the parameters, like power in the couplers and accelerating fields in the cavities, are within the state of the art, achieved in operating machines. A first stage of operation at 30 mA beam current is proposed, while the upgrade of the machine to 120 mA operation can be obtained increasing the number of klystrons and couplers per cavity. The additional coupler ports, up to four, will be integrated in the cavity design. Preliminary calculations indicate that beam transport is feasible, given the wide aperture of the 352 MHz structures. A capital cost of less than 100 M$ at 10 mA, reaching up to 280 M$ for the 120 mA extension, has been estimated for the superconducting high energy section (100 MeV-1 GeV). The high effic...

High time resolution beam-based measurement of the rf-to-laser jitter in a photocathode rf gun

Directory of Open Access Journals (Sweden)

Zhen Zhang

2014-03-01

Full Text Available Characterizing the rf-to-laser jitter in the photocathode rf gun and its possible origins is important for improving the synchronization and beam quality of the linac based on the photocathode rf gun. A new method based on the rf compression effect in the photocathode rf gun is proposed to measure the rf-to-laser jitter in the gun. By taking advantage of the correlation between the rf compression and the laser injection phase, the error caused by the jitter of the accelerating field in the gun is minimized and thus 10 fs time resolution is expected. Experimental demonstration at the Tsinghua Thomson scattering x-ray source with a time resolution better than 35 fs is reported in this paper. The experimental results are successfully used to obtain information on the possible cause of the jitter and the accompanying drifts.

Numerical investigation of transient beam loading compensation in JLC X-band main linac

International Nuclear Information System (INIS)

Syrachev, I.V.; Higo, T.

1996-06-01

In the present paper, two methods, 'staggered timing' and 'RF modulation', were studied for the transient beam loading compensation in the JLC X-band main linac. The inter bunch energy spread was found to be easily reduced down to less than ±0.06% with 10 sets of injection timings along the linac in the former case while with a simple linear ramping of the input RF voltage in the latter case. For both cases the energy transfer efficiencies from the power source to the beam were exactly the same. The tolerance of the beam intensity jitter was found to be ±1% for the multibunch energy spread of ±0.1%. (author)

Development of the rf linear accelerator test bed for heavy-ion fusion

International Nuclear Information System (INIS)

Watson, J.M.

1981-01-01

The amount of absorbed energy required by high gain deuterium-tritium targets for inertial confinement fusion reactors is now projected to be greater than 1 Megajoule. It has become apparent that a heavy ion fusion driver is the preferred choice in this scenario. To demonstrate this accelerator-based option, the national program has established two test beds: one at Argonne for the rf linac/storage ring approach, and one at Lawrence Berkeley Laboratory developing an induction linac. The Argonne Beam Development Facility (BDF) would consist of a 40 mA rf linac for Xe + 8 , a storage ring, and a 10 GeV synchrotron. The design and status of the BDF is described as well as future program options to demonstrate as many solutions as possible of the issues involved in this approach

An inexpensive PC-based ion linac control system

International Nuclear Information System (INIS)

Hamm, M.E.; Potter, J.M.

1991-01-01

A turn-key PC-based control system has been developed for the AccSys line of compact ion linear accelerators and rf power amplifiers. The control interface is based on the DZERO Rack Monitor Module, developed at Fermi National Accelerator Laboratory, communicating with a Ballard Technology MIL-STD-1553B controller board in a 286 or 386 personal computer. This cost effective and easy to operate control system features real-time control and monitoring of the linac/rf amplifier and can be customized for automatic start-up and unattended operation

Linac 1 in the process of being pulled back

CERN Multimedia

Photographic Service; CERN PhotoLab

1985-01-01

As injector to the PS Booster, Linac 1 was replaced by Linac 2 in 1980. It continued to be used for the acceleration of oxygen and sulfur ions and, from 1981 to 1996, of protons and negative hydrogen ions for LEAR. In 1984, its Cockcroft-Walton preinjector was replaced by a much smaller RFQ, which allowed it to be moved to a more convenient location.

Status of rf superconductivity at Argonne National Laboratory

International Nuclear Information System (INIS)

Markovich, P.M.; Shepard, K.W.; Zinkann, G.P.

1987-01-01

This paper reports the status of hardware development for the linac portion of the Argonne tandem-linac accelerator system (ATLAS). The ATLAS superconducting linac consists of an independent-phased array of 45 superconducting niobium resonators of the split-ring type. The linac has been operating in its present form since 1985, on a 24-hours per day, 5 days per week schedule. An upgrade of the ATLAS system is currently under construction the positive-ion injector (PII). The PII system will consist of an ECR positive-ion source mounted on a high-voltage platform injecting a very-low-velocity superconducting linac. The completed system will provide for the acceleration of beams of mass up to uranium, and will replace the tandem electrostatic accelerator as the injector for ATLAS. The status of resonator development for the superconducting linac is reported in this paper. Accelerating gradients in the existing ATLAS linac are currently limited by excessive heating and rf loss in the fast-tuning system associated with each superconducting resonator. Development of an upgraded fast-tuning system is also reported here. 7 refs., 5 figs

NSRL 200 MeV linac beam energy stabilization system

International Nuclear Information System (INIS)

Huang Guirong; Pei Yuanji; Dong Sai

2001-01-01

By using the computer image processing technology and RF phase auto-shifting system, the ESS (Energy Stabilization System) was applied to 200 MeV Linac. the ESS adjusts beam energy automatically in a range of +-4 MeV. After adjustment beam energy stability is improved to +-6%

Muon Acceleration Concepts for NuMAX: "Dual-use" Linac and "Dogbone" RLA

Science.gov (United States)

Bogacz, S. A.

2018-02-01

We summarize the current state of a concept for muon acceleration aimed at a future Neutrino Factory. The main thrust of these studies was to reduce the overall cost while maintaining performance by exploring the interplay between the complexity of the cooling systems and the acceptance of the accelerator complex. To ensure adequate survival for the short-lived muons, acceleration must occur at high average gradient. The need for large transverse and longitudinal acceptances drives the design of the acceleration system to an initially low RF frequency, e.g., 325 MHz, which is then increased to 650 MHz as the transverse size shrinks with increasing energy. High-gradient normal conducting RF cavities at these frequencies require extremely high peak-power RF sources. Hence superconducting RF (SRF) cavities are chosen. We consider two cost effective schemes for accelerating muon beams for a stageable Neutrino Factory: exploration of the so-called "dual-use" linac concept, where the same linac structure is used for acceleration of both H- and muons and, alternatively, an SRF-efficient design based on a multi-pass (4.5) "dogbone" RLA, extendable to multi-pass FFAG-like arcs.

Progress of the accelerator R and D for the Japanese Hadron Project

International Nuclear Information System (INIS)

Kihara, Motohiro

1991-01-01

This paper will describe the general idea of the JHP facility, primarily from the accelerator's point of view, and up-to-data results of the research and development on accelerator components. Among others, the R and D on the proton linac has been pursued at the KEK Laboratory since 1987, efforts having been devoted mainly to the development of prototype rf power sources, the rf structure development for the coupled-cell linac and the realization of a 10-MeV linac. The R and D study on the heavy-ion linac has been made at Institute for Nuclear Study, University of Tokyo, primarily on the split-coaxial RFQ linac. (author)

Preliminary parameter assessments of a spiral FFAG accelerator for proton therapy

International Nuclear Information System (INIS)

Smirnov, V.L.; Azaryan, N.S.; Vorozhtsov, S.B.

2013-01-01

Fixed-Field Alternating-Gradient (FFAG) accelerator was invented in the 1950-60s but never progressed beyond the model stage. Starting from 2000, new interest in this type of accelerator arose. Given advantages of the FFAG over the synchrotron, cyclotron and linac, there are many possible applications of the accelerator. Among them, we are mostly interested in acceleration of protons and light ions for hadron therapy. In this connection a preliminary set of parameters of the facility was estimated and, in particular, the magnetic sector shape and corresponding dynamical properties of the magnetic field of the accelerator were calculated. In addition, preliminary considerations about the RF system design are given.

Transport and energy selection of laser generated protons for postacceleration with a compact linac

Science.gov (United States)

Sinigardi, Stefano; Turchetti, Giorgio; Londrillo, Pasquale; Rossi, Francesco; Giove, Dario; De Martinis, Carlo; Sumini, Marco

2013-03-01

Laser accelerated proton beams have a considerable potential for various applications including oncological therapy. However, the most consolidated target normal sheath acceleration regime based on irradiation of solid targets provides an exponential energy spectrum with a significant divergence. The low count number at the cutoff energy seriously limits at present its possible use. One realistic scenario for the near future is offered by hybrid schemes. The use of transport lines for collimation and energy selection has been considered. We present here a scheme based on a high field pulsed solenoid and collimators which allows one to select a beam suitable for injection at 30 MeV into a compact linac in order to double its energy while preserving a significant intensity. The results are based on a fully 3D simulation starting from laser acceleration.

Development of an Eddy Current Septum for LINAC4

CERN Document Server

Barnes, M; Borburgh, J; Fowler, T; Goddard, B; Ueda, A; Weterings, W

2008-01-01

A linear accelerator (linac) is the first stage of the CERN accelerator complex. The linac defines the beam quality for subsequent stages of acceleration and the reliability has to be high as a fault of the linac shuts down all other machines. The existing linacs at CERN were designed 30 or more years ago: recent upgrades allowed the linacs to reach LHC requirements but also showed that they are at the limit of their brightness and intensity capabilities. A replacement Superconducting Proton Linac (SPL) has been proposed; the initial part of the SPL is termed LINAC4. The LINAC4 injection bump would be made up of a set of four pulsed dipole magnets; the first of these magnets (BS1) must act as a septum with a thin element dividing the high-field region of the circulating beam from the field-free region through which injected $H^{-}$ beam must pass. The initial specifications for BS1 required; a deflection of 66 mrad at 160 MeV, achieved with a peak field of 628 mT and a length of 250 mm: the field fall time wa...

Multiple-linac approach for tritium production and other applications

International Nuclear Information System (INIS)

Ruggiero, A.G.

1995-01-01

This report describes an approach to tritium production based on the use of multiple proton linear accelerators. Features of a single APTT Linac as proposed by the Los Alamos National Laboratory are presented and discussed. An alternative approach to the attainment of the same total proton beam power of 200 MW with several lower-performance superconducting Linacs is proposed and discussed. Although each of these accelerators are considerable extrapolations of present technology, the latter can nevertheless be built at less technical risk when compared to the single high-current APT Linac, particularly concerning the design and the performance of the low-energy front-end. The use of superconducting cavities is also proposed as a way of optimizing the accelerating gradient, the overall length, and the operational costs. The superconducting technology has already been successfully demonstrated in a number of large-size projects and should be seriously considered for the acceleration of intense low-energy beams of protons. Finally, each linear accelerator would represent an ideal source of very intense beams of protons for a variety of applications, such as: weapons and waste actinide transmutation processes, isotopes for medical application, spallation neutron sources, and the generation of intense beams of neutrinos and muons for nuclear and high-energy physics research. The research community at large has obviously an interest in providing expertise for, and in having access to, the demonstration, the construction, the operation, and the exploitation of these top-performance accelerators

The FELIX RF system

International Nuclear Information System (INIS)

Manintveld, P.; Delmee, P.F.M.; Geer, C.A.J. van der; Meddens, B.J.H.; Meer, A.F.G. van der; Amersfoort, P.W. van

1992-01-01

The performance of the RF system for the Free Electron Laser for Infrared eXperiments (FELIX) is discussed. The RF system provides the input power for a triode gun (1 GHz, 100 W), a prebuncher (1 GHz, 10 kW), a buncher (3 GHz, 20 MW), and two linacs (3 GHz, 8 MW each). The pulse length in the system is 20 μs. The required electron beam stability imposes the following demands on the RF system: a phase stability better than 0.3 deg for the 1 GHz signals and better than 1 deg for the 3 GHz signals; the amplitude stability has to be better than 1% for the 1 GHz and better than 0.2% for the 3 GHz signals. (author) 3 refs.; 6 figs

Status of Tristan superconducting RF program

International Nuclear Information System (INIS)

Noguchi, S.; Akai, K.; Arinaga, M.

1988-01-01

The TRISTAN accelerator complex consists of an injector linac system, an accumulation ring (AR) and a main colliding beam ring (MR). The injector linac system is composed of a 2.5 GeV main linac, a 200 MeV high current (10 A) linac for positron generation and a 250 MeV positron preaccelerator. These linacs are now operated with a pulse width of 2 nsec and a repetition rate of 20 pps, which is raised to 50 pps in the near future. The TRISTAN AR is used as a beam accumulator and energy booster for the TRISTAN MR, and additionally it can be operated as an electron-positron collider and as a storage ring for the synchrotron radiation research. The electron (positron) beam of 50 mA (10 mA) peak current is injected from the main linac. The accumulation rate of positrons is now typically 5 mA/min. There are 8 RF cavity sections in two long straight sections, of which 6 sections are occupied by 11 cell APS cavities and 2 sections are used for the beam test of the superconducting cavities. The TRISTAN MR was designed so that it could achieve as high energy as possible for its size, therefore it has very long straight sections for RF cavities. The normal conducting cavities, which are 9-cell APS type and have a shunt impedance of 22.5 M Omega/m, are distributed to 3 straight sections. The remaining straight section named NIKKO division, is allotted to the superconducting cavities. MR accelerated the first electron beam to 25.5 GeV on 24th of October 1986. The energy upgrading program was approved in 1986 and the construction of 32 5-cell superconducting cavities and a 4.5 KW helium refrigerator system started. It is expected that the accelerating field and the Q value are better than 5 MV/m and 1 x 10 9 , respectively. 8 references, 13 figures, 4 tables

Conception, construction et essai d'un accélérateur linéaire à protons impulsé à 3 GHz (LIBO) pour la thérapie du cancer

CERN Document Server

Berra, Paolo; De Conto, J M; Demeyer, A; Gerard, J P; Hoffmann, H F; Remillieux, J; Bajard, M; Rosso, E; Szeless, Balázs; Weiss, M

2005-01-01

In the last ten years the use of proton beams in radiation therapy has become a clinical tool for treatment of deep-seated tumours. LIBO is a RF compact and low cost proton linear accelerator (SCL type) for hadrontherapy. It is conceived by TERA Foundation as a 3 GHz Linac Booster, to be mounted downstream of an existing cyclotron in order to boost the energy of the proton beam up to 200 MeV, needed for deep treatment (~25 cm) in the human body. With this solution it is possible to transform a low energy commercial cyclotron, normally used for eye melanoma therapy, isotope production and nuclear physics research, into an accelerator for deep-seated tumours. A prototype module of LIBO has been built and successfully tested with full RF power at CERN and with proton beam at INFN Laboratori Nazionali del Sud (LNS) in Catania, within an international collaboration between TERA Foundation, CERN, the Universities and INFN groups of Milan and Naples. The mid-term aim of the project is the technology transfer of the ...

High power RF systems for LEHIPA of ADS

International Nuclear Information System (INIS)

Pande, Manjiri; Shrotriya, Sandip; Sharma, Sonal; Rao, B.V.R.; Mishra, J.K.; Patel, Niranjan; Gupta, S.K.

2011-01-01

Worldwide accelerator driven sub-critical system (ADS) has generated a huge interest for various reasons. In India, as a part of accelerator driven sub-critical system (ADS) program, a normal conducting, low energy high intensity proton accelerator (LEHIPA) of energy 20 MeV and beam current of 30 mA is being developed in Bhabha Atomic Research Centre (BARC). LEHIPA comprises of Electron Cyclotron Resonance (ECR) ion source (50 KeV), Radio Frequency Quadrupole (RFQ) accelerator (3 MeV) and Drift tube Linac (DTL) 1 and 2 (10 MeV and 20 MeV respectively). As per the accelerator physics design, RFQ requires nearly 530 kW RF power while each of DTL need 900 kW. Each accelerating cavity will be driven by a one- megawatt (CW) klystron based high power RF (HPRF) system at 352.21 MHz. Three such RF systems will be developed. The RF system has been designed around five cavity klystron tube TH2089F (Thales make) capable of delivering 1 MW continuous wave power at 352.21 MHz. The klystron has a gain of 40 dB and efficiency around 62 %. Each of the RF system comprises of a low power solid state driver (∼ 100 W), klystron tube, harmonic filter, directional coupler, Y-junction circulator (AFT make), RF load and WR2300 wave guide based RF transmission line each of 1 MW capacity. It also includes other subsystems like bias supplies (high voltage (HV) and low voltage (LV)), HV interface system, interlock and protection circuits, dedicated low conductivity water-cooling, pulsing circuitry/mechanisms etc. WR 2300 based RF transmission line transmits and feeds the RE power from klystron source to respective accelerating cavity. This transmission line starts from second port of the circulator and consists of straight sections, full height to half height transition, magic Tee, termination load at the centre of magic tee, half height sections, directional couplers and RE windows. For X-ray shielding, klystron will be housed in a lead (3 mm) based shielded cage. This system set up has a

LCLS-II high power RF system overview and progress

Energy Technology Data Exchange (ETDEWEB)

Yeremian, Anahid Dian

2015-10-07

A second X-ray free electron laser facility, LCLS-II, will be constructed at SLAC. LCLS-II is based on a 1.3 GHz, 4 GeV, continuous-wave (CW) superconducting linear accelerator, to be installed in the first kilometer of the SLAC tunnel. Multiple types of high power RF (HPRF) sources will be used to power different systems on LCLS-II. The main 1.3 GHz linac will be powered by 280 1.3 GHz, 3.8 kW solid state amplifier (SSA) sources. The normal conducting buncher in the injector will use four more SSAs identical to the linac SSAs but run at 2 kW. Two 185.7 MHz, 60 kW sources will power the photocathode dual-feed RF gun. A third harmonic linac section, included for linearizing the bunch energy spread before the first bunch compressor, will require sixteen 3.9 GHz sources at about 1 kW CW. A description and an update on all the HPRF sources of LCLS-II and their implementation is the subject of this paper.

Development of a digital high-frequency regulation for the pulsed operation of the proton-linac test facility at FAIR; Entwicklung einer digitalen Hochfrequenzregelung fuer den gepulsten Betrieb des Protonenlinac Teststandes bei FAIR

Energy Technology Data Exchange (ETDEWEB)

Nonn, Patrick Walter

2014-06-16

At the site of the GSI Helmholtzzentrum fuer Schwerionenforschung near Darmstadt, the international Facility for Antiproton and Ion Research (FAIR) is under construction. The research program of FAIR includes experiments with antiproton beams. In order to provide the high intensity proton beam, that is necessary to produce the antiprotons, a new linear accelerator, acting as injector to the SIS18 synchrotron, will be constructed. This linear accelerator, called p-Linac, shall be kept as short as possible. That is why novel CH-type cavities will be used for the main acceleration from 3 MeV to 70 MeV. In order to test these novel cavities and their supporting technology, an rf test stand is under construction at GSI. Within the scope of this thesis a pulsed 325 MHz control system has been developed as part of that test stand. It is based upon the cw rf control system of the superconducting Darmstaedter Linearaccelerator (S-DALINAC), that is designed to drive normal- and superconducting cavities at 3 GHz. Aim of this thesis is, to adapt the frequency of S-DALINAC's rf control to p-Linac's 325 MHz at one hand and on the other hand, to improve the response time in order to achieve a relative amplitude error of below 10{sup -3} and a phase error below 0.1 within the 200 μs long rf pulses. The time that is needed in order to re-achieve the errors after the beam pulse hits the cavity, is also crucial. At first, the dependance of the control rate to various parameters of the cavity and the control has been tested by analytical and numerical methods. Therefore, the behavior of a cavity's amplitude in the base band has been modeled and confirmed by comparison of the model's and a measured step response of a cavity. The dependance of the I- and PI-control's parameters on the decay time of the cavity was shown by analytical methods. With the aid of numerical simulations the extent at which the response time is affected negatively by dead time and

Electromagnetic design of a β=0.4 superconducting spoke resonator for a high intensity proton linac

International Nuclear Information System (INIS)

Pathak, Abhishek; Krishnagopal, Srinivas

2015-01-01

Here we present electromagnetic design simulations of a superconducting single-spoke resonator with a geometrical beta of 0.4 and operating at 325 MHz for a high intensity proton linac (HIPL). The spoke equatorial and base parameters were optimized to minimize the peak electric and peak magnetic fields and maximize the shunt impedance, while keeping the same resonant frequency. Variation of the surface magnetic fields was investigated as a function of the spoke base shape, and it was found that an elliptical profile is preferred over a circular or racecourse profile with E peak /E acc =4.71, E peak /E acc =4.33 (mT/(MV/m)) and R/Q=272 Ω. (author)

Progress in the fabrication of the RFQ accelerator for the CERN Linac4

CERN Document Server

Rossi, C; Lallement, J B; Lombardi, A M; Mathot, S; Pugnat, D; Timmins, M; Vandoni, G; Vretenar, M; Desmons, M; France, A; Le Noa, Y; Novo, G; Piquet, O

2010-01-01

The construction of Linac4, the new 160 MeV CERN H- injector, has started with the goal of improving the LHC injection chain from 2015 with a new higher energy linac. The low energy front end of Linac4 is based on a 352 MHz, 3-m long Radiofrequency Quadrupole (RFQ) accelerator [1]. The RFQ accelerates the 70 mA, 45 keV H- beam from the RF source to the energy of 3 MeV. The fabrication of the RFQ has started at CERN in 2009 and is presently in progress, aiming at the completion of the full structure by early 2011. The RFQ consists of three modules, one meter each; the fabrication alternates machining phases and stress relief cycles, for copper stabilization. Two brazing steps are required: one to assemble the four parts composing a module, and a second one to install the stainless steel flanges. In order to monitor that the tight mechanical and alignment budget is not exceeded, metrology measurements at the CERN workshop and RF bead-pull measurements are performed during the fabrication process. In this paper ...

Development of a high intensity proton accelerator

International Nuclear Information System (INIS)

Mizumoto, Motoharu; Kusano, Joichi; Hasegawa, Kazuo; Ito, Nobuo; Oguri, Hidetomo; Touchi, Yutaka; Mukugi, Ken; Ino, Hiroshi

1997-01-01

The high-intensity proton linear accelerator with a beam power of 15 MW has been proposed for various engineering tests for the nuclear waste transmutation system as one of the research plans in the Neutron Science Research Program (NSRP) in JAERI. High intensity proton beam and secondary particle beams such as neutron, pion, muon and unstable radio isotope (RI) beam generated from the proton spallation reaction will be utilized at these facilities in each research field. The R and D work has been carried out for the components of the front-end part of the proton accelerator; ion source, RFQ, DTL and RF source. In the beam test, the current of 70 mA with a duty factor of 7% has been accelerated from the RFQ at the energy of 2 MeV. A hot test model of the DTL for the high power and high duty operation was fabricated and tested. For the high energy portion above 100 MeV, superconducting accelerating cavity is studied as a main option. The superconducting linac is expected to have several favourable characteristics for high intensity accelerator such as short accelerator length, large bore radius resulting in low beam losses and cost effectiveness for construction and operation. A test stand with equipment of cryogenics system, vacuum system, RF system and cavity processing and cleaning is prepared to test the physics issues and fabrication process. The proposed plan for accelerator design and construction will compose of two consecutive stages. The first stage will be completed in about 7 years with the beam power of 1.5 MW. As the second stage gradual upgrading of the beam power will be made up to 15 MW. 7 refs., 3 figs., 4 tabs

A P + DEUTERON PROTON POLARIMETER AT 200 MEV.

Energy Technology Data Exchange (ETDEWEB)

HUANG,H.; ROSER,T.; ZELENSKI,A.; KURITA,K.; STEPHENSON,E.; TOOLE,R.

2002-06-02

There has been concern about the analyzing power of the p-Carbon polarimeter at the end of 200 MeV LINAC of BNL. A new polarimeter based on proton-deuteron scattering was installed and we have repeated the calibration of proton-Carbon scattering at 12 degrees and 200 MeV against proton-deuteron scattering. The result is consistent with the value of A=0.62 now used to measure the beam polarization at the end of the LINAC.

rf measurements and tuning of the 750 MHz radio frequency quadrupole

Directory of Open Access Journals (Sweden)

Benjamin Koubek

2017-08-01

Full Text Available In the framework of the program on medical applications a compact 750 MHz RFQ has been designed and built to be used as an injector for a hadron therapy linac. This RFQ was designed to accelerate protons to an energy of 5 MeV within only 2 m length. It is divided into four segments and equipped with 32 tuners in total. The length of the RFQ corresponds to 5λ which is considered to be close to the limit for field adjustment using only piston tuners. Moreover the high frequency, which is about double the frequency of existing RFQs, results in a sensitive structure and requires careful tuning. In this paper we present the tuning algorithm, the tuning procedure and rf measurements of the RFQ.

A digital closed loop control system for automatic phase locking of superconducting cavities of IUAC Linac

International Nuclear Information System (INIS)

Dutt, R.N.; Rai, A.; Pandey, A.; Sahu, B.K.; Patra, P.; Karmakar, J.; Chaudhari, G.K.; Mathur, Y.; Ghosh, S.; Kanjilal, D.

2013-01-01

A closed loop digital control system has been designed and tested to automate the tuning process of superconducting resonators of LINAC at Inter-University Accelerator Centre, New Delhi. The mechanism controls the proportional valves of the He gas based pneumatic tuner in response to the phase and frequency errors of the cavity RF field. The main RF phase lock loop (PLL) is automatically closed once the resonant frequency is within locking range of the resonator PLL. The digital control scheme was successfully tested on few resonators of LINAC cryostat 1. A high stability of phase lock was observed. The details of the digital automation system are presented in the paper. (author)

Transport and energy selection of laser generated protons for postacceleration with a compact linac

Directory of Open Access Journals (Sweden)

Stefano Sinigardi

2013-03-01

Full Text Available Laser accelerated proton beams have a considerable potential for various applications including oncological therapy. However, the most consolidated target normal sheath acceleration regime based on irradiation of solid targets provides an exponential energy spectrum with a significant divergence. The low count number at the cutoff energy seriously limits at present its possible use. One realistic scenario for the near future is offered by hybrid schemes. The use of transport lines for collimation and energy selection has been considered. We present here a scheme based on a high field pulsed solenoid and collimators which allows one to select a beam suitable for injection at 30 MeV into a compact linac in order to double its energy while preserving a significant intensity. The results are based on a fully 3D simulation starting from laser acceleration.

Linear collider RF structure design using ARGUS

International Nuclear Information System (INIS)

Kwok Ko

1991-01-01

In a linear collider, both the driving system (klystrons) and the accelerating system (linac) consists of RF structures that are inherently three-dimensional. These structures which are responsible for power input/output, have to satisfy many requirements in order that instabilities, beam or RF related, are to be avoided. At the same time, system efficiencies have to be maintained at optimal to minimize cost. Theoretical analysis on these geometrically complex structures are difficult and until recently, numerical solutions have been limited. At SLAC, there has been a continuing and close collaboration among accelerator physicists, engineers and numericists to integrate supercomputing into the design procedure which involves 3-D RF structures. The outcome is very encouraging. Using the 3-D/electromagnetic code ARGUS (developed by SAIC) on the Cray computers at NERSC in conjunction with supporting theories, a wide variety of critical components have been simulated and evaluated. Aside from structures related to the linear collider, the list also includes the RF cavity for the proposed Boson Factory and the anode circuit for the Cross-Field Amplifier, once considered as an alternative to the klystron as a possible power source. This presentation will focus on two specific structures: (1) the klystron output cavity; and (2) the linac input coupler. As the results demonstrate, supercomputing is fast becoming a viable technology that could conceivably replace actual cold-testing in the near future

RF study and 3-D simulations of a side-coupling thermionic RF-gun

International Nuclear Information System (INIS)

Rimjaem, S.; Kusoljariyakul, K.; Thongbai, C.

2014-01-01

A thermionic RF-gun for generating ultra-short electron bunches was optimized, developed and used as a source at a linac-based THz radiation research laboratory of the Plasma and Beam Physics Research Facility, Chiang Mai University, Thailand. The RF-gun is a π/2-mode standing wave structure, which consists of two S-band accelerating cells and a side-coupling cavity. The 2856 MHz RF wave is supplied from an S-band klystron to the gun through the waveguide input-port at the cylindrical wall of the second cell. A fraction of the RF power is coupled from the second cell to the first one via a side-coupling cavity. Both the waveguide input-port and the side-coupling cavity lead to an asymmetric geometry of the gun. RF properties and electromagnetic field distributions inside the RF-gun were studied and numerically simulated by using computer codes SUPERFISH 7.19 and CST Microwave Studio 2012 © . RF characterizations and tunings of the RF-gun were performed to ensure the reliability of the gun operation. The results from 3D simulations and measurements are compared and discussed in this paper. The influence of asymmetric field distributions inside the RF-gun on the electron beam properties was investigated via 3D beam dynamics simulations. A change in the coupling-plane of the side-coupling cavity is suggested to improve the gun performance

RF study and 3-D simulations of a side-coupling thermionic RF-gun

Science.gov (United States)

Rimjaem, S.; Kusoljariyakul, K.; Thongbai, C.

2014-02-01

A thermionic RF-gun for generating ultra-short electron bunches was optimized, developed and used as a source at a linac-based THz radiation research laboratory of the Plasma and Beam Physics Research Facility, Chiang Mai University, Thailand. The RF-gun is a π/2-mode standing wave structure, which consists of two S-band accelerating cells and a side-coupling cavity. The 2856 MHz RF wave is supplied from an S-band klystron to the gun through the waveguide input-port at the cylindrical wall of the second cell. A fraction of the RF power is coupled from the second cell to the first one via a side-coupling cavity. Both the waveguide input-port and the side-coupling cavity lead to an asymmetric geometry of the gun. RF properties and electromagnetic field distributions inside the RF-gun were studied and numerically simulated by using computer codes SUPERFISH 7.19 and CST Microwave Studio 2012©. RF characterizations and tunings of the RF-gun were performed to ensure the reliability of the gun operation. The results from 3D simulations and measurements are compared and discussed in this paper. The influence of asymmetric field distributions inside the RF-gun on the electron beam properties was investigated via 3D beam dynamics simulations. A change in the coupling-plane of the side-coupling cavity is suggested to improve the gun performance.

Argonne National Laboratory 1980-1981 tandem-linac accelerator report

International Nuclear Information System (INIS)

Hartog, P.D.; Pardo, R.; Munson, F.; Heath, C.

1981-01-01

Performance of the facility is discussed. The FN tandem Van de Graaff is now used as an injector for the superconducting linac; heavy-ion beams are being injected. Stripper foil development is described, with fabrication by arc evaporation and by RF discharge compared. Facility modifications, such as the control room, are discussed

Low Level RF Including a Sophisticated Phase Control System for CTF3

CERN Document Server

Mourier, J; Nonglaton, J M; Syratchev, I V; Tanner, L

2004-01-01

CTF3 (CLIC Test Facility 3), currently under construction at CERN, is a test facility designed to demonstrate the key feasibility issues of the CLIC (Compact LInear Collider) two-beam scheme. When completed, this facility will consist of a 150 MeV linac followed by two rings for bunch-interleaving, and a test stand where 30 GHz power will be generated. In this paper, the work that has been carried out on the linac's low power RF system is described. This includes, in particular, a sophisticated phase control system for the RF pulse compressor to produce a flat-top rectangular pulse over 1.4 µs.

High power RF performance test of an improved SiC load

Energy Technology Data Exchange (ETDEWEB)

Hwang, W.H.; Kim, S.H.; Park, Y.J. [Pohang Accelerator Lab., Pohang Inst. of Sceince and Technology, Pohang (KR)] [and others

1998-11-01

Two prototypes of SiC loads sustaining a maximum peak power of 50 MW were fabricated by Nihon Koshuha Co. in Japan. The PAL conducted the high power RF performance tests of SiC loads to verify the operation characteristics for the application to the PLS Linac. The in-situ facility for the K 12 module was used for the test, which consists of a modulator and klystron system, waveguide network, vacuum and cooling system, and RF analyzing equipment. As the test results, no breakdown appeared up to 50 MW peak power of 1 {mu}s pulse width at a repetition rate of 50 Hz. However, as the peak power increased above 20 MW at 4 {mu}s with 10 Hz, the breakdown phenomena has been observed. Analysing the test results with the current operation power level of PLS Linac, it is confirmed that the SiC loads well satisfy the criteria of the PLS Linac operation. (author)

Design of high-energy high-current linac with focusing by superconducting solenoids

Energy Technology Data Exchange (ETDEWEB)

Batskikh, G.I.; Belugin, V.M.; Bondarev, B.I. [Moscow Radiotechnical Institute (Russian Federation)] [and others

1995-10-01

The advancement of MRTI design for 1.5 GeV and 250 mA ion CW linac was presented in a previous report. In this new linac version all the way from input to output the ions are focused by magnetic fields of superconducting solenoids. The ion limit current is far beyond the needed value. The linac focusing channel offers major advantages over the more conventional ones. The acceptance is 1.7 times as large for such focusing channel as for quadrupole one. Concurrently, a random perturbation sensitivity for such channel is one order of magnitude smaller than in quadrupole channel. These focusing channel features allow to decrease beam matched radius and increase a linac radiation purity without aperture growth. {open_quotes}Regotron{close_quotes} is used as high power generator in linac main part. But D&W cavities need not be divided into sections connected by RF-bridges which denuded them of high coupling factor.

Analysis and software development for controlling RF signal generator proton cyclotron Decy-13 using DDS Technique

International Nuclear Information System (INIS)

Prajitno

2012-01-01

Analysis and manufacture of computer programs for controlling the signal generator Radio Frequency (RF) proton cyclotron Decy-13 have been done. Signal generator uses a technique Direct Digital Synthesiser (DDS) which settings must be done with software. Signal generator consists of electronic modules which are: DDS, micro controller ATmega16, amplifier RF.dan ± 12 Vdc power supply. Function of the programs that have been made is to set the DDS module, namely: output frequency, step frequency and phase settings and displays the operating parameters of the DDS and the RF amplifier on the monitor screen. Computer programs created with Visual Basic and has been tested to control the RF signal generator to send data serially to the module ATmega16 and receives data to be displayed on the monitor screen. Testing sending and receiving data is done with a baudrate of 1200 bps to 19200 bps with perfect results. Computer programs that have been made equipped with a Human Machine Interface to provide values parameter input on the DDS operations. (author)

Development of C-band High-Power Mix-Mode RF Window

CERN Document Server

Michizono, S; Matsumoto, T; Nakao, K; Takenaka, T

2004-01-01

High power c-band (5712 MHz) rf system (40 MW, 2 μs, 50 Hz) is under consideration for the electron-linac upgrade aimed for the super KEKB project. An rf window, which isolates the vacuum and pass the rf power, is one of the most important components for the rf system. The window consists of a ceramic disk and a pill-box housing. The mix-mode rf window is designed so as to decrease the electric field on the periphery of the ceramic disk. A resonant ring is assembled in order to examine the high-power transmission test. The window was tested up to the transmission power of 160 MW. The rf losses are also measured during the rf operation.

Long term performance of the superconducting cavities of the Saclay heavy ion linac

International Nuclear Information System (INIS)

Cauvin, B.; Desmons, M.; Girard, J.; Letonturier, P.

1993-12-01

The Saclay heavy ion superconducting linac has been in operation at full energy since mid 1989. The 50 independent superconducting helix resonators have now accelerated beams for more than 20000 hours. The long term performances of the linac, and more specifically of the superconducting R.F. technology, are discussed: vibrations of the resonators, cryostat design and operation, beam time, vacuum accidents, multipactor during operation due to small leaks, stability of the electric fields, cryogenics operation. 4 figs., 6 refs

DESIGN AND FABRICATION OF THE BEAM POSITION MONITOR FOR THE PEFP LINAC

Directory of Open Access Journals (Sweden)

HYEOK-JUNG KWON

2013-08-01

Full Text Available The beam position monitor (BPM is an essential component for the PEFP 100-MeV linac's commissioning. A prototype stripline-type linac BPM was designed for this purpose. The electrode aperture is 20 mm in diameter, and the electrode is 25 mm long, so it can be installed between Drift Tube Linac (DTL101 and DTL102, which is the shortest distance. One end of the electrode is connected to the Sub Miniature Type A (SMA feed through for signal measurement, and the other end is terminated as a short. The signal amplitude of the fundamental component was calculated and compared with that of the second harmonic component. The designed BPM was fabricated and a low-power RF test was conducted. In this paper, the design, fabrication and low power test of the BPM for the PEFP linac are presented.

Effects Of Field Distortions In Ih-apf Linac

CERN Document Server

Kapin, Valery; Yamada, S

2004-01-01

The project on developing compact medical accelera-tors for the tumor therapy using carbon ions has been started at the National Institute of Radiological Sciences (NIRS). Alternating-phase-focused (APF) linac using an interdigital H-mode (IH) cavity has been proposed for the injector linac. The IH-cavity is doubly ridged circular resonator loaded by the drift-tubes mounted on ridges with supporting stems. The effects of intrinsic and random field distortions in a practical design of the 4-MeV/u 200 MHz IH-APF linac are considered. The intrinsic field distortions in IH-cavity are caused by the asymmetry of the gap field due to presence of the drift-tube supporting stems and pair of ridges. The random field distortions are caused by drift-tube misalignments and non-regular deviations of the voltage distribution from programmed law. The RF fields in IH-cavity have been calculated using Microwave Studio (MWS) code. The effects of field distortions on beam dynamics have been simulated numerically.

High-brightness electron guns for linac-based light sources

International Nuclear Information System (INIS)

Lewellen, J.W.

2004-01-01

Most proposed linac-based light sources, such as single-pass free-electron lasers and energy-recovery-linacs, require very high-brightness electron beams in order to achieve their design performance. These beam requirements must be achieved not on an occasional basis, but rather must be met by every bunch produced by the source over extended periods of time. It is widely assumed that the beam source will be a photocathode electron gun; the selection of accelerator technique (e.g., dc or rf) for the gun is more dependent on the application.The current state of the art of electron beam production is adequate but not ideal for the first generation of linac-based light sources, such as the Linac Coherent Light Source (LCLS) x-ray free-electron laser (X-FEL). For the next generation of linac-based light sources, an order of magnitude reduction in the transverse electron beam emittance is required to significantly reduce the cost of the facility. This is beyond the present state of the art, given the other beam properties that must be maintained. The requirements for current and future linac-based light source beam sources are presented here, along with a review of the present state of the art. A discussion of potential paths towards meeting future needs is presented at the conclusion.

The PS complex as proton pre-injector for the LHC - design and implementation report

International Nuclear Information System (INIS)

Benedikt, M.; Blas, A.; Borburgh, J.

2000-01-01

The LHC will be supplied with protons from the pre-injector chain comprising Linac2, PS Booster and PS. These accelerators have undergone a major upgrading programme during the last five years so as to meet the stringent requirements of the LHC. This implies that many high-intensity bunches of small emittance and tight spacing (25 ns) be available at the PS extraction energy (26 GeV/c). The upgrading project involved an increase of Linac2 current, new RF systems in the PS Booster and the PS, raising the PS Booster energy from 1 to 1.4 GeV, two-batch filling of the PS, and the installation of high-resolution beam profile measurement devices. With the project entering its final phase and most of the newly installed hardware now being operational, the emphasis switches to producing the nominal LHC beam and tackling the associated beam physics problems. This report describes all the hardware changes related to the upgrading project. (orig.)

Linac Coherent Light Source Undulator RF BPM System

International Nuclear Information System (INIS)

Lill, R.M.; Morrison, L.H.; Waldschmidt, G.J.; Walters, D.R.; Argonne; Johnson, R.; Li, Z.; Smith, S.; Straumann, T.; SLAC

2007-01-01

The Linac Coherent Light Source (LCLS) will be the world's first x-ray free-electron laser (FEL) when it becomes operational in 2009. The LCLS is currently in the construction phase. The beam position monitor (BPM) system planned for the LCLS undulator will incorporate a high-resolution X-band cavity BPM system described in this paper. The BPM system will provide high-resolution measurements of the electron beam trajectory on a pulse-to-pulse basis and over many shots. The X-band cavity BPM size, simple fabrication, and high resolution make it an ideal choice for LCLS beam position detection. We will discuss the system specifications, design, and prototype test results

Overview of superconducting RF technology and its application to high-current linacs

International Nuclear Information System (INIS)

Delayen, J.R.; Bohn, C.L.

1994-01-01

Superconducting linacs may be a viable option for high-current applications such as copious neutron production like that needed for transmutation of radioactive waste. These linacs must run reliably for many years and allow easy routine maintenance. superconducting cavities operate efficiently with high cw gradients, properties which help to reduce operating and capital costs. However, cost effectiveness is not the sole consideration in these applications. For example, beam impingement must be essentially eliminated to prevent unsafe radioactivation of the accelerating structures, and thus large apertures are needed through which to pass the beam. Because of their high efficiency, superconducting cavities can be designed with very large bore apertures, thereby reducing the effect of beam impingement

Computer codes for designing proton linear accelerators

International Nuclear Information System (INIS)

Kato, Takao

1992-01-01

Computer codes for designing proton linear accelerators are discussed from the viewpoint of not only designing but also construction and operation of the linac. The codes are divided into three categories according to their purposes: 1) design code, 2) generation and simulation code, and 3) electric and magnetic fields calculation code. The role of each category is discussed on the basis of experience at KEK (the design of the 40-MeV proton linac and its construction and operation, and the design of the 1-GeV proton linac). We introduce our recent work relevant to three-dimensional calculation and supercomputer calculation: 1) tuning of MAFIA (three-dimensional electric and magnetic fields calculation code) for supercomputer, 2) examples of three-dimensional calculation of accelerating structures by MAFIA, 3) development of a beam transport code including space charge effects. (author)

Conceptual Design of the Linac4 Main Dump

CERN Document Server

Leitao, I V; Maglioni, C

2012-01-01

Linac4 is the new CERN linear accelerator intended to replace the ageing Linac2 as the injector to the Proton Synchrotron Booster (PSB) for increasing the luminosity of the Large Hadron Collider (LHC). By delivering a 160MeV H- beam, Linac4 will provide the necessary conditions to double the brightness and intensity of the beam extracted from the PSB. This paper describes the conceptual design of the Linac4 Main Dump, where two different concepts relying respectively on water and air cooling were compared and evaluated. Based on the application of analytical models for the energy deposited by the beam, heat conduction and cooling concepts, a parametric study was performed. This approach allowed the identification of the “optimal” configuration for these two conceptual geometries and their relative comparison. Besides giving the theoretical guidelines for the design of the new dump, this work also contributes to the development of analytical tools to allow a better understanding of the influence of the se...

Beam dynamics pre-design with KONUS principle for the DTL of SPPC p-Linac

Science.gov (United States)

Liu, Jing; Li, Haipeng; Lu, Yuanrong; Su, Jiancang; Liu, Xiaolong; Fu, Qi

2018-04-01

As the Higgs bosons were observed on the LHC in 2012, a two-stage particle collider program named CEPC-SPPC is proposed for precise measurement of Higgs properties and exploring the new physics models. In order to deliver a 2.1-TeV proton beam into the Super Proton-Proton Collider (SPPC), the injector chain will use a 1.2-GeV proton linac (p-Linac) and three synchrotrons of p-RCS, MSS and SS. This paper focuses on the preliminary conceptual design of the DTL within the p-Linac and mainly concerns about the beam dynamics studies. Taking advantages of the KONUS principle and LORASR code, a 325 MHz, 50.65 MeV DTL design which is composed of three tanks in 15.6 m will be presented. The whole DTL contains 129 gaps for beam acceleration, one quadruple doublet which is behind the buncher and eight quadruple triplets of which three are located after each tank, respectively. The aims of this pre-study are to optimize the acceleration electric field distribution together with the focusing magnetic field parameters, enhance the beam transmission quality of beam envelopes, particle distribution and energy spread, then improve the DTL performance in terms of transmission efficiency and so on. The results of the analyses show that the DTL pre-design achieves 16.8 times high energy gain and meets all the p-Linac requirements well.

New technology of lead-tin plating of superconducting RF resonators for the ANU LINAC

International Nuclear Information System (INIS)

Lobanov, N.R.; Weisser, D.C.

2003-01-01

The RF accelerating resonators for the ANU superconducting LINAC have been re-plated with lead-tin and their performance substantially improved. The re-plating was at first derailed by the appearance of dendrites on the surface. This problem was overcome by a new combination of two techniques. Rather than the standard process of chemically stripping the old Pb and hand polishing the Cu substrate the unsatisfactory Pb surface was mechanically polished and then re-plated. This is enormously easier, faster and doesn't put at risk the thin cosmetic electron beam welds or the repaired ones. Reverse pulse plating was then used to re-establish an excellent superconducting surface. Average acceleration fields of 3.5 to 3.9 MV/m have been achieved. The re-plated resonators will double the energy gain of the accelerator significantly extending capability of the facility research. Lead-tin plating provides fast adequate results with modest equipment and at relatively low cost. SUNY re-plated six high-beta SLRs with 2 microns of Pb-Sn using a modern, commercial, methane-sulfonate process (Lea Ronal Solderon MHS-L) and a simple open-air procedure. This proven success motivated ANU to adopt MSA chemistry and to re-plate the first SLR in November 1998 followed by re-plating all twelve SLRs by November 2002. This increased the booster energy gain by almost 100%

Gallium arsenide digital integrated circuits for controlling SLAC CW-RF systems

International Nuclear Information System (INIS)

Ronan, M.T.; Lee, K.L.; Corredoura, P.; Judkins, J.G.

1989-01-01

In order to fill the PEP and SPEAR storage rings with beams from the SLC linac and damping rings, precise control of the linac subharmonic buncher and the damping ring RF is required. Recently several companies have developed resettable GaAs master/slave D-type flip-flops which are capable of operating at frequencies of 3 GHz and higher. Using these digital devices as frequency dividers, one can phase shift the SLAC CW-RF systems to optimize the timing for filling the storage rings. The authors have evaluated the performance of integrated circuits from two vendors for our particular application. Using microstrip circuit techniques, they have built and operated in the accelerator several chassis to synchronize a reset signal from the storage rings to the SLAC 2.856 GHz RF and to phase shift divide-by-four and divide-by-sixteen frequency dividers to the nearest 350 psec bucket required for filling

Gallium arsenide digital integrated circuits for controlling SLAC CW-RF systems

International Nuclear Information System (INIS)

Ronan, M.T.; Lee, K.L.; Corredoura, P.; Judkins, J.G.

1988-10-01

In order to fill the PEP and SPEAR storage rings with beams from the SLC linac and damping rings, precise control of the linac subharmonic buncher and the damping ring RF is required. Recently several companies have developed resettable GaAs master/slave D-type flip-flops which are capable of operating at frequencies of 3 GHz and higher. Using these digital devices as frequency dividers, one can phase shift the SLAC CW-RF systems to optimize the timing for filling the storage rings. We have evaluated the performance of integrated circuits from two vendors for our particular application. Using microstrip circuit techniques, we have built and operated in the accelerator several chassis to synchronize a reset signal from the storage rings to the SLAC 2.856 GHz RF and to phase shift divide-by-four and divide-by-sixteen frequency dividers to the nearest 350 psec bucket required for filling. 4 refs., 4 figs., 2 tabs

RF study and 3-D simulations of a side-coupling thermionic RF-gun

Energy Technology Data Exchange (ETDEWEB)

Rimjaem, S., E-mail: sakhorn.rimjaem@cmu.ac.th [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics (ThEP), Commission on Higher Education, Bangkok 10400 (Thailand); Kusoljariyakul, K.; Thongbai, C. [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics (ThEP), Commission on Higher Education, Bangkok 10400 (Thailand)

2014-02-01

A thermionic RF-gun for generating ultra-short electron bunches was optimized, developed and used as a source at a linac-based THz radiation research laboratory of the Plasma and Beam Physics Research Facility, Chiang Mai University, Thailand. The RF-gun is a π/2-mode standing wave structure, which consists of two S-band accelerating cells and a side-coupling cavity. The 2856 MHz RF wave is supplied from an S-band klystron to the gun through the waveguide input-port at the cylindrical wall of the second cell. A fraction of the RF power is coupled from the second cell to the first one via a side-coupling cavity. Both the waveguide input-port and the side-coupling cavity lead to an asymmetric geometry of the gun. RF properties and electromagnetic field distributions inside the RF-gun were studied and numerically simulated by using computer codes SUPERFISH 7.19 and CST Microwave Studio 2012{sup ©}. RF characterizations and tunings of the RF-gun were performed to ensure the reliability of the gun operation. The results from 3D simulations and measurements are compared and discussed in this paper. The influence of asymmetric field distributions inside the RF-gun on the electron beam properties was investigated via 3D beam dynamics simulations. A change in the coupling-plane of the side-coupling cavity is suggested to improve the gun performance.

RF emittance in a low energy electron linear accelerator

Science.gov (United States)

Sanaye Hajari, Sh.; Haghtalab, S.; Shaker, H.; Kelisani, M. Dayyani

2018-04-01

Transverse beam dynamics of an 8 MeV low current (10 mA) S-band traveling wave electron linear accelerator has been studied and optimized. The main issue is to limit the beam emittance, mainly induced by the transverse RF forces. The linac is being constructed at Institute for Research in Fundamental Science (IPM), Tehran Iran Labeled as Iran's First Linac, nearly all components of this accelerator are designed and constructed within the country. This paper discusses the RF coupler induced field asymmetry and the corresponding emittance at different focusing levels, introduces a detailed beam dynamics design of a solenoid focusing channel aiming to reduce the emittance growth and studies the solenoid misalignment tolerances. In addition it has been demonstrated that a prebuncher cavity with appropriate parameters can help improving the beam quality in the transverse plane.

RF Processing of the Couplers for the SNS Superconducting Cavities

International Nuclear Information System (INIS)

Y.Kang; I.E. Campisi; D. Stout; A. Vassioutchenko; M. Stirbet; M. Drury; T. Powers

2005-01-01

All eighty-one fundamental power couplers for the 805 MHz superconducting cavities of the SNS linac have been RF conditioned and installed in the cryomodules successfully. The couplers were RF processed at JLAB or at the SNS in ORNL: more than forty couplers have been RF conditioned in the SNS RF Test Facility (RFTF) after the first forty couplers were conditioned at JLAB. The couplers were conditioned up to 650 kW forward power at 8% duty cycle in traveling and standing waves. They were installed on the cavities in the cryomodules and then assembled with the airside waveguide transitions. The couplers have been high power RF tested with satisfactory accelerating field gradients in the cooled cavities

The booster linac of the Sparkle Company 18 MeV Cyclotron: main design elements

International Nuclear Information System (INIS)

Picardi, L.; Ronsivalle, C.

2009-01-01

The Sparkle Company (Casarano, Le) that is setting up a centre for production and research on radioisotopes for medical use, has requested to the ENEA Accelerator Laboratory a specific design of a linear accelerator for boosting the energy of its commercial cyclotron from 18 to 24 MeV, with the aim of implementing a small proton irradiation facility for radiobiology studies. This is the first case of coupling a cyclotron beam to a linac, that, if successful, can give rise to a new class of accelerators for proton therapy. The linac can accelerate only a very small portion of the cyclotron beam, due to the intrinsic mismatching of the two kind of accelerators both in the vertical and in the longitudinal phase planes. A beam transport line has been studied that besides matching at best the beam to the linac in the transverse plane, is equipped with a chopping system to lower drastically the primary beam power in order to protect the linac structure. The linac is SCDTL type, and operates at 3 GHz. In the following the results of the design are presented. [it

Linac4 RFQ assembly is carried out before installation in Building 152

CERN Multimedia

Anna Pantelia

2012-01-01

This series of pictures documents the assembly phase of the Linac4 RFQ (Radio Frequency Quadrupole), performed at the end of July 2012. The Linac4 RFQ is made of 3 modules, 1 meter each, assembled together to accelerate the H- or proton beam from the ion source extraction at 45 kV to the energy of 3 MeV. The RFQ is the first of the Linac4 accelerating structures, which will increase to 160 MeV the beam injection energy into the PS Booster as from the end of LS2.

High current induction linacs

International Nuclear Information System (INIS)

Barletta, W.; Faltens, A.; Henestroza, E.; Lee, E.

1994-07-01

Induction linacs are among the most powerful accelerators in existence. They have accelerated electron bunches of several kiloamperes, and are being investigated as drivers for heavy ion driven inertial confinement fusion (HIF), which requires peak beam currents of kiloamperes and average beam powers of some tens of megawatts. The requirement for waste transmutation with an 800 MeV proton or deuteron beam with an average current of 50 mA and an average power of 40 MW lies midway between the electron machines and the heavy ion machines in overall difficulty. Much of the technology and understanding of beam physics carries over from the previous machines to the new requirements. The induction linac allows use of a very large beam aperture, which may turn out to be crucial to reducing beam loss and machine activation from the beam halo. The major issues addressed here are transport of high intensity beams, availability of sources, efficiency of acceleration, and the state of the needed technology for the waste treatment application. Because of the transformer-like action of an induction core and the accompanying magnetizing current, induction linacs make the most economic sense and have the highest efficiencies with large beam currents. Based on present understanding of beam transport limits, induction core magnetizing current requirements, and pulse modulators, the efficiencies could be very high. The study of beam transport at high intensities has been the major activity of the HIF community. Beam transport and sources are limiting at low energies but are not significant constraints at the higher energies. As will be shown, the proton beams will be space-charge-dominated, for which the emittance has only a minor effect on the overall beam diameter but does determine the density falloff at the beam edge

The JHP 200-MeV proton linear accelerator

Energy Technology Data Exchange (ETDEWEB)

Kato, Takao [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)

1997-11-01

A 200-MeV proton linear accelerator for the Japanese Hadron Project (JHP) has been designed. It consists of a 3-MeV radio-frequency quadrupole linac (RFQ), a 50-MeV drift tube linac (DTL) and a 200-MeV separated-type drift tube linac (SDTL). A frequency of 324 MHz has been chosen for all of the rf structures. A peak current of 30 mA (H{sup -} ions) of 400 {mu}sec pulse duration will be accelerated at a repetition rate of 25 Hz. A future upgrade plan up to 400 MeV is also presented, in which annular-coupled structures (ACS) of 972 MHz are used in an energy range of above 150 or 200 MeV. One of the design features is its high performance for a beam-loss problem during acceleration. It can be achieved by separating the transition point in the transverse motion from that of the longitudinal motion. The transverse transition at a rather low-energy range decreases the effects of space-charge, while the longitudinal transition at a rather high-energy range decreases the effects of nonlinear problems related to acceleration in the ACS. Coupled envelope equations and equipartitioning theory are used for the focusing design. The adoption of the SDTL structure improves both the effective shunt impedance and difficulties in fabricating drift tubes with focusing magnets. An accurate beam-simulation code on a parallel supercomputer was used for confirming any beam-loss problem during acceleration. (author)

A development plan for the Fermilab proton source

International Nuclear Information System (INIS)

Holmes, S. D.

1997-01-01

The present Fermilab Proton Source is composed of a 750 KV ion source, a 400 MeV Linac, and an 8 GeV Booster synchrotron. This facility currently provides proton beams at intensities up to 5 x 10 10 protons/bunch for injection into the Main Ring in support of the current Tevatron fixed target run. Following completion of the Main Injector project in 1999, the Proton Source is expected to provide protons to the Main Injector at an intensity of 6 x 10 10 protons/bunch as required to meet established performance goals for Tevatron Collider Run II. With the advent of the Main Injector the demand for protons in support of a diverse physics research program at Fermilab will grow. This is because the Main Injector creates a new capability for simultaneous operation of the collider and fixed target programs at 120 GeV. It has also been recently appreciated that a physics program based on the utilization of unallocated 8 GeV Booster cycles is potentially very attractive. A variety of experiments are either approved or under consideration including the Neutrinos at the Main Injector (NUMI) project, Kaons at the Main Injector (KAMI), and an rf separated K + beam for CPT tests, all utilizing 120 GeV protons, and a low energy neutrino (MiniBooNe) or muon program based on 8 GeV protons from the Booster. In addition significant effort is now being invested in defining paths to a factor of five improvement in Tevatron collider luminosity beyond those expected in Run II and in understanding the possible future siting of either a very large hadron collider or a modest energy ''First Muon Collider'' (FMC) at Fermilab. Support for these varied activities is beyond the capabilities of the current Proton Source--in the case of the FMC by about a factor of ten as measured in delivered protons per second. The purpose of this document is to describe a possible evolution of the Fermilab Proton Source over the next ten years. The goal is to outline a staged plan, with significant

Superconducting linac beam dynamics with high-order maps for RF resonators

CERN Document Server