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1997
We present parameters for a 5-TeV-c.m. linear collider that would fit on the proposed Next Linear Co llider (NLC) [1] site and use 34-GHz accelerator structures. Supporting arguments are given for the choice of important parameters, and changes required for each machine section are described. This work should be considered preliminary, as a full 5-TeV upgrade would require extensive study.
2000
An electron/positron linear collider with a center-of-mass energy between 0.5 and 1 TeV would be an important complement to the physics program of the LHC in the next decade. The Next Linear Collider (NLC) is being designed by a US collaboration (FNAL, LBNL, LLNL, and SLAC) which is working closely with the Japanese collaboration that is designing the Japanese Linear Collider (JLC). The NLC main linacs are based on normal conducting 11 GHz rf. This paper will discuss the technical difficulties encountered as well as the many changes that have been made to the NLC design over the last year. These changes include improvements to the X-band rf system as well as modifications to the injector and the beam delivery system. They are based on new conceptual solutions as well as results from the R&D programs which have exceeded initial specifications. The net effect has been to reduce the length of the collider from about 32 km to 25 km and to reduce the number of klystrons and modulators by a factor of two. Together these lead to significant cost savings.
Acta Physica Polonica B, 1999
The CLIC study of high-energy (0.5-5 TeV), high-luminosity (1034-1035cm-2{s}-1) e± linear collider is presented. Beam acceleration using high-frequency (30 GHz) normal-conducting structures operating at high accelerating fields (100 to 200 MV/m) significantly reduces the length and, in consequence, the cost of the linac. Based on new beam and linac parameters derived from a recently developed set of general scaling laws for linear colliders, the beam stability is shown to be similar to lower frequency designs in spite of the strong wake-field dependency on frequency. A new cost-effective and efficient drive beam generation scheme for RF power production by the so-called Two Beam Acceleration (TBA) method is described. It uses a thermionic gun and a fully-loaded normal-conducting linac operating at low frequency (937 MHz) to generate and accelerate the drive beam bunches, and RF multiplication by funnelling in compressor rings to produce the desired bunch structure. Recent 30 GHz hardware developments and results from the CLIC Test Facility (CTF), assessing the feasibility of the scheme, are described.}
1993
At SLAC, the authors are pursuing the design of a Next Linear Collider (NLC) which would begin with a center-of-mass energy of 0.5 TeV, and be upgradable to at least 1.0 TeV. To achieve this high energy, they have been working on the development of a high-gradient 11.4-GHz (X-band) linear accelerator for the main linac of the collider. In this
Proceedings Particle Accelerator Conference, 1995
In this paper, we present the parameters and layout of the Next Linear Collider (NLC). The NLC is the SLAC design of a future linear collider using X-band RF technology in the main linacs. The collider would have an initial centerof-mass energy of 0.5 TeV which would be upgraded to 1 TeV and then 1.5 TeV in two stages. The design luminosity is > 5 10 33 cm 2 sec 1 at 0.5 TeV and > 10 34 cm 2 sec 1 at 1.0 and 1.5 TeV. We will brie y describe the components of the collider and the proposed energy upgrade scenario.
The progress of the Compact LInear Collider (CLIC) study of a multi-TeV (0.5 - 5 TeV) high-luminosity (5K1033 to 1.5K1035 cm-2 sec-1) e H linear collider based on Two-Beam Acceleration (TBA) is presented. The length and, in consequence, the cost of the overall complex is reduced by the use of high accelerating fields (150 MV/m), which are generated by specially damped 30 GHz normal-conducting accelerating structures. The large amount of RF power (400 MW/m) required to generate these high fields is provided by a novel RF power generating ...
2018
The Compact Linear Collider (CLIC) is a TeV-scale high-luminosity linear $e^+e^−$ collider under development at CERN. Following the CLIC conceptual design published in 2012, this report provides an overview of the CLIC project, its current status, and future developments. It presents the CLIC physics potential and reports on design, technology, and implementation aspects of the accelerator and the detector. For an optimal exploitation of its physics potential, CLIC is foreseen to be built and operated in stages, at centre-of-mass energies of 380 GeV, 1.5 TeV and 3 TeV, respectively, for a site length ranging from 11 km to 50 km. CLIC uses a two-beam acceleration scheme, in which normal-conducting high-gradient 12 GHz accelerating structures are powered via a high-current drive beam. For the first stage, an alternative with X-band klystron powering is also considered. CLIC accelerator optimisation, technical developments and system tests have resulted in significant progress in recen...
The CLIC study of a high-energy (0.5 - 5 TeV), high-luminosity (1034 - 1035 cm-2 sec-1) e± linear collider is presented. Beam acceleration using high frequency (30 GHz) normal-conducting structures operating at high accelerating fields (150 MV/m) significantly reduces the length and, in consequence, the cost of the linac. Using parameters derived from general scaling laws for linear colliders, the beam stability is shown to be similar to lower frequency designs in spite of the strong wake-field dependency on frequency. A new cost-effective and efficient drive beam generation scheme for RF power production by the so-called "Two-Beam Acceleration" method is described. It uses a thermionic gun and a fully-loaded normal-conducting linac operating at low frequency (937 MHz) to generate and accelerate the drive beam bunches, and RF multiplication by funnelling in compressor rings to produce the desired bunch structure. Recent 30 GHz hardware developments and CLIC Test Facility (...
International Journal of Modern Physics A, 2013
In this paper, we describe the key features of the recently completed technical design for the International Linear Collider (ILC), a 200–500 GeV linear electron–positron collider (expandable to 1 TeV) that is based on 1.3 GHz superconducting radio-frequency (SCRF) technology. The machine parameters and detector characteristics have been chosen to complement the Large Hadron Collider physics, including the discovery of the Higgs boson, and to further exploit this new particle physics energy frontier with a precision instrument. The linear collider design is the result of nearly 20 years of R&D, resulting in a mature conceptual design for the ILC project that reflects an international consensus. We summarize the physics goals and capability of the ILC, the enabling R&D and resulting accelerator design, as well as the concepts for two complementary detectors. The ILC is technically ready to be proposed and built as a next generation lepton collider, perhaps to be built in stages begin...
2005
A high luminosity (10 34 -10 35 cm 2 /s) electron-positron Collider (CLIC) with a nominal centreof-mass energy of 3 TeV has been under study for a number of years in the framework of an international collaboration of laboratories and institutes, with the aim to provide the HEP community with a new facility for the post-LHC era. After a brief description of a CLIC scheme to extend Linear Colliders into the Multi-TeV colliding beam energy range, the main challenges and the very promising results already achieved will be presented. The presentation will mainly focus on the new Test Facility (CTF3) presently under construction at CERN in order to address the main key issues and demonstrate the feasibility of the CLIC technology before 2010.
2004
Designs for a future TeV scale electron-positron Xband linear collider (NLC/GLC) require main linac units which produce and deliver 450 MW of rf power at 11.424 GHz to eight 60 cm accelerator structures. The design of this rf unit includes a SLED-II pulse compression system with a gain of approximately three at a compression ratio of four, followed by an over-moded transmission and distribution system. We have designed, constructed, and operated such a system as part of the 8-Pack project at SLAC. Four 50 MW X-band klystrons, running off a common 400 kV solid-state modulator, drive a dualmoded SLED-II pulse compression system. The compressed power is delivered to structures in the NLCTA beamline. Four 60 cm accelerator structures are currently installed and powered, with four additional structures and associated high power components available for installation late in 2004. We describe the layout of our system and the various high-power components which comprise it. We also present preliminary data on the processing and initial high-power operation of this system.
1999
The CLIC study of a high energy (0.5 -5 TeV), high luminosity (10 34 -10 35 cm -2 sec -1 ) e H linear collider is presented. Beam acceleration using high frequency (30 GHz) normal-conducting structures operating at high accelerating fields (150 MV/m) significantly reduces the length and, in consequence, the cost of the linac. Based on new beam and linac parameters derived from a recently developed set of general scaling laws for linear colliders, the beam stability is shown to be similar to lower frequency designs in spite of the strong wake-field dependency on frequency. A new costeffective and efficient drive beam generation scheme for RF power production by the so-called "Two Beam Acceleration (TBA)" method is described. It uses a thermionic gun and a fully-loaded normal-conducting linac operating at low frequency (937 MHz) to generate and accelerate the drive beam bunches, and RF multiplication by funnelling in compressor rings to produce the desired bunch structure. Recent 30 GHz hardware developments and results from the CLIC Test Facility (CTF), assessing the feasibility of the scheme, are described.
From the beginning, the R&D on linear colliders has been a significantly international activity involving a large number of scientists and engineers from laboratories and universities not limited to the members of the ISG. Attempts are made to attribute proper credit in the reference section of each chapter to those who contributed important ideas to the development of JLC/NLC, irrespective of the country or organization. However, due to the extent of the work, it is not necessarily always possible to accurately identify the original sources of various ideas or designs. The ISG members express gratitude for all the contributions and apologize in advance for any possible omissions.
2000
The CLIC study of a high-energy (0.5 -5 TeV), high-luminosity (10 34 -10 35 cm -2 sec -1 ) e ± linear collider is presented. Beam acceleration using high frequency (30 GHz) normal-conducting structures operating at high accelerating fields (150 MV/m) significantly reduces the length and, in consequence, the cost of the linac. Using parameters derived from general scaling laws for linear colliders, the beam stability is shown to be similar to lower frequency designs in spite of the strong wake-field dependency on frequency. A new cost-effective and efficient drive beam generation scheme for RF power production by the so-called "Two-Beam Acceleration" method is described. It uses a thermionic gun and a fully-loaded normal-conducting linac operating at low frequency (937 MHz) to generate and accelerate the drive beam bunches, and RF multiplication by funnelling in compressor rings to produce the desired bunch structure. Recent 30 GHz hardware developments and CLIC Test Facility (CTF) results are described.
Proceedings of International Conference on Particle Accelerators
The design for the Next Linear Collider (NLC) at SLAC is based on two 11.4 GHz linacs operating at an unloaded acceleration gradient of 50 MV/m increasing to 85 MV/m as the energy is increased from 1/2 TeV to 1 TeV in the center of mass[1]. During the past several years there has been tremendous progress on the development of 11.4 GHz (X-band) RF systems. These developments include klystrons which operate at the required power and pulse length, pulse compression systems that achieve a factor of four power multiplication and structures that are specially designed to reduce long-range wakefields. Together with these developments, we have constructed a 1/2 GeV test accelerator, the NLC Test Accelerator (NLCTA). The NLCTA will serve as a test bed as the design of the NLC is refined. In addition to testing the RF system, the NLCTA is designed to address many questions related to the dynamics of the beam during acceleration, in particular the study of multibunch beam loading compensation and transverse beam break-up. In this paper we present the status of the NLCTA and the results of initial commissioning.
… Physica Polonica B, 1999
The CLIC study of a high energy (0.5 - 5 TeV), high luminosity (1034 - 1035 cm-2 sec-1) e ± linear collider is presented. Beam acceleration using high frequency (30 GHz) normal-conducting structures operating at high accelerating fields (100 to 200 MV/m) significantly reduces the length ...
1995
A description of the original CLIC two-beam scheme is given in . The overall layout of the 1 TeV machine is shown in . The main linac consists of normal conducting travelling wave accelerating structures operating at a frequency of 30 GHz and a gradient of 80 MV/m. One in ten of these sections have an asymmetric geometry and act as microwave quadrupoles for BNS damping. For multi-bunch operation damped and/or detuned structures would be required. The 30 GHz RF power is supplied by transfer structures which extract energy from a 3 GeV high-intensity electron drive linac running parallel to the main linac in the same tunnel. The transfer structure consists of a 11.5 mm diameter circular beam tube coupled through two diametrically-opposite ≈5mm wide slots to two periodicallyloaded rectangular waveguides. Each 50 cm long section produces two simultaneous 11.6 ns long 44.6 MW power pulses which drive two accelerating structures. This output power corresponds to 95% of the energy extracted from the beam. Two full-length (84 cell) constant impedance undamped accelerating section have been tested to an average accelerating gradient of 94 MV/m without any signs of breakdown and the periodically-loaded output waveguides of a full-length transfer structure have withstood 60 MW of 30 GHz RF power without breakdown but the structure itself has not yet been tested with a bunched beam Prototype diamond machined discs with the asymmetric geometry required for microwave quadrupole sections have been successfully produced by industry, and studies of damped structures for multibunch operation are underway. High gradient tests have also been made at SLAC on a 26-cell CERN-built X-band section . Average accelerating gradients of 125 MV/m (a peak surface field of 285 MV/m) were obtained after 10 7 shots at 60 Hz with a pulse length of 150 ns. After conditioning, the dark current was 2µA at 50 MV/m and 150µA at 80 MV/m.
Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366), 1999
At the present time, there are a number of future linear collider designs with a center-of-mass energy of 500 GeV or more that have luminosities in excess of 10 34 cm ,2 s ,1. Many of these designs are very advanced, however, to attain the high luminosity, the colliders require very small beam emittances, strong focusing, and very good stability. In this paper, some of the outstanding issues related to the small spot sizes are discussed. Although the different designs are based very different rf technologies, many of these problems are common to all designs.
2013
Common preamble to Parts I and II The International Linear Collider (ILC) is a linear electron-positron collider based on 1.3 GHz superconducting radio-frequency (SCRF) accelerating technology. It is designed to reach 200-500 GeV (extendable to 1 TeV) centre-of-mass energy with high luminosity. The design is the result of over twenty years of linear collider R&D, beginning in earnest with the construction and operation of the SLC at SLAC. This was followed by extensive development work on warm X-band solutions (NLC/JLC) and the pioneering work by the TESLA collaboration in the 1990s on superconducting L-band RF. In 2004, the International Technology Review Panel, set up by the International Committee for Future Accelerators, ICFA, selected superconducting technology for ILC construction. The Global Design Effort (GDE) was set up by ICFA in 2005 to coordinate the development of this technology as a worldwide international collaboration. Drawing on the resources of over 300 national laboratories, universities and institutes worldwide, the GDE produced the ILC Reference Design Report (RDR) [1-4] in August 2007. The report describes a conceptual design for the ILC and gives an estimated cost and the required personnel from collaborating institutions. The work done by the GDE during the RDR phase identified many high-risk challenges that required R&D, which have subsequently been the focus of the worldwide activity during the Technical Design Phase. This phase has achieved a significant increase in the achievable gradient of SCRF cavities through a much better understanding of the factors that affect it. This improved understanding has permitted the industrialisation of the superconducting RF technology to more than one company in all three regions, achieving the TDP goal of 90 % of industrially produced cavities reaching an accelerating gradient of 31.5 MV/m. A further consequence is an improved costing and construction schedule than was possible in the RDR. Other important R&D milestones have included the detailed understanding of the effects of, and effective mitigation strategies for, the "electron-cloud" effects that tend to deteriorate the quality of the positron beam, particularly in the ILC damping rings. The achievement of the R&D goals of the TDR has culminated in the publication of this report, which represents the completion of the GDE's mandate; as such, it forms a detailed solution to the technical implementation of the ILC, requiring only engineering design related to a site-specific solution to allow the start of construction. Volume 3 (Accelerator) of the Technical Design Report is divided into two separate parts reflecting the GDE's primary goals during the Technical Design Phase period (2007-2012): Part I: R&D in the Technical Design Phase summarises the programmes and primary results of the risk-mitigating worldwide R&D including industrialisation activities. Part II: Baseline Design provides a comprehensive summary of the reference layout, parameters and technical design of the accelerator, including an updated cost and construction schedule estimate. The R&D results and studies of cost-effective solutions for the collider presented in Part I directly support the design presented in Part II, which is structured as a technical reference.
arXiv (Cornell University), 2000
The CLIC study of a high-energy (0.5-5 TeV), high-luminosity (10 34-10 35 cm-2 sec-1) e H linear collider is presented. Beam acceleration using high frequency (30 GHz) normal-conducting structures operating at high accelerating fields (150 MV/m) significantly reduces the length and, in consequence, the cost of the linac. Using parameters derived from general scaling laws for linear colliders, the beam stability is shown to be similar to lower frequency designs in spite of the strong wake-field dependency on frequency. A new cost-effective and efficient drive beam generation scheme for RF power production by the so-called "Two-Beam Acceleration" method is described. It uses a thermionic gun and a fully-loaded normal-conducting linac operating at low frequency (937 MHz) to generate and accelerate the drive beam bunches, and RF multiplication by funnelling in compressor rings to produce the desired bunch structure. Recent 30 GHz hardware developments and CLIC Test Facility (CTF) results are described. Figure 1: Overall layout of the CLIC complex.
2011
SuperConduCtIng radIoFrequenCy teChnology 2.1 Putting superconducting radiofrequency technology to the test for the ILC 2.2 Development of worldwide infrastructure 2.3 Progress towards manufacture of high-gradient cavities 2.4 Cryomodule design and development 2.5 High-power radiofrequency development 2.6 System integrations tests aCCelerator SyStem r&d 3.1 The electron cloud R&D programme at CesrTA and other laboratories 3.2 The ATF2 final focus test beamline at KEK 3.3 Accelerator systems R&D aCCelerator deSIgn & IntegratIon 4.1 Evolving design beyond the Reference Design Report 4.2 Layout and design 4.3 Parameters ConventIonal FaCIlItIeS and SItIng 5.1 Global conventional facilities design 5.2 Life safety and infrastructure support 5.3 Site-specific design efforts towardS the teChnICal deSIgn report 6.1 A focus on mass production and cost 6.2 Consolidating R&D 6.3 The Project Implementation Plan 6.4 Beyond the Technical Design Report
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