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With coordination from the APS Renewal Steering Committee (the members of which are the co-authors of this paper), staff and users of the U.S. Department of Energy’s Advanced Photon Source (APS) at Argonne National Laboratory are in the process of developing a renewal plan for the facility. The renewal is a coordinated upgrade of the accelerator, beamlines, and associated technical structure that will enable users of the APS to address key scientific challenges in the coming decades. The cost of the renewal is estimated to be from $300M to $400M and to take approximately six years from start to finish. [ABSTRACT FROM AUTHOR]

In the baseline Neutrino Factory muon front end, strong, closely spaced solenoid magnets are used to contain the high emittance muon beam. In addition, significant acceleration is required for bunching, phase rotation and cooling, requiring RF cavities operating near to their maximum achievable gradient. There are experimental indications that RF cavities may not be able to achieve these large gradients in the presence of such intense magnetic fields. In this paper, I discuss the design of a muon cooling channel that is designed with RF cavities removed from the intense magnetic fields, and examine the change in performance that results from this compromise. [ABSTRACT FROM AUTHOR]

Accelerator Driven Systems (ADS) for nuclear waste transmutation require proton drivers with energies between 600 and 800 MeV and beam currents of several mA for demonstrators and up to 25 mA for large industrial systems. Within the EUROTRANS project a 600 MeV linac has been designed to meet the stringent requirements regarding reliability, availability and extreme low beam losses. The first accelerating section using the novel CH-cavity accelerates the beam to 17 MeV at the injection point into the main linac. The intermediate energy section (17–100 MeV) of the main linac consists of superconducting independently phased spoke-type cavities followed by the high energy section consisting of 704 MHz superconducting elliptical cavities. The paper covers the development of the linac, prototype testing and reliability considerations of the whole EUROTRANS project. [ABSTRACT FROM AUTHOR]

Liquid Argon Time Projection Chamber technology provides unique features in event imaging and calorimetric resolution. These characteristics, combined with a good rejection power and a (virtually) unlimited active mass, make this detector one of the best candidate for the next generation of long-baseline neutrino oscillation experiments aimed at precision measurements of the MNPS matrix elements. Up to now the largest LAr-TPC operated is the first semi-module of the ICARUS T600 detector (300 tons of LAr). The scalability of this technology to massive detectors (>=5 ktons) is still to be proven. The ArgoNeuT detector, a small LAr-TPC (0.24 ton of active mass) exposed to the NuMI beam at FNAL currently producing the first low-energy neutrino events in a LAr-TPC, is the first step of a staged US program to realize and operate a massive LAr-TPC detector. The proposed MicroBooNE experiment, a LAr-TPC of 100 tons of active mass, to be exposed to the Booster Neutrino Beam and the NuMI beam at FNAL, is the next crucial step of this program. Design details and experimental goals of both experiments are reported in this paper. [ABSTRACT FROM AUTHOR]

The next generation of long baseline neutrino oscillation experiments, aiming at precision measurements of the MNSP matrix element, will be focused on the “few GeV” energy range. For these experiments one of the main sources of uncertainty is the poor knowledge of the v-nucleus interaction cross-section, dominated in this energy range by the QE channel contribution. The LAr-TPC technology is ideal to perform a wide variety of v-physics studies in the intermediate energy range, thanks to the capability of single particle identification and detailed reconstruction of exclusive topologies. The present paper reports a feasibility study for the measurement of the QE CC cross-section for the vμ-nucleus interaction in liquid Argon, using the ArgoNeuT detector on the NuMI Beam and the MINOS Near Detector as muon catcher. The estimated relative tatistical error between 1 and 4 GeV is at the level of 4–5%, below the beam systematics. The present status of the ArgoNeuT experiment is also reported. [ABSTRACT FROM AUTHOR]

Accelerating gradient is a key parameter of the accelerating structure in large linac facilities, like future Linear Collider. In room temperature accelerating structures the gradient is limited mostly by breakdown phenomena, caused by high surface electric fields or pulse surface heating. High power processing is a necessary procedure to clean surface and improve the gradient. In the best tested X-band structures the achieved gradient is exceed 100 MV/m in of ∼200 ns pulses for breakdown rate of ∼10-7. Gradient limit depends on number of factors and no one theory which can explain all sets of experimental results and predict gradient in new accelerating structure. In paper we briefly overview the recent experimental results of breakdown studies, progress in understanding of gradient limitations and scaling laws. Although superconducting rf technology has been adopted throughout the world for ILC, it has frequently been difficult to reach the predicted performance in these structures due to a number of factors: multipactoring, field emission, Q-slope, thermal breakdown. In paper we are discussing all these phenomena and the ways to increase accelerating gradient in SC cavity, which are a part of worldwide R & D program. [ABSTRACT FROM AUTHOR]

More than 60 years after the later Nobel laureate Hannes Alfvén had published a letter stating that oscillating magnetic fields can accelerate ionised matter via magneto-hydrodynamic interactions in a wave like fashion, the technical implementation of Alfvén waves for propulsive purposes has been proposed, patented and examined for the first time by a group of inventors. The name of the concept is MOA—Magnetic field Oscillating Amplified thruster. Based on computer simulations, MOA is a highly flexible propulsion system, whose performance parameters might easily be adapted, by changing the mass flow and/or the power level. As such the system is capable to deliver a maximum specific impulse of 13116 s (12.87 mN) at a power level of 11.16 kW, using Xe as propellant, but can also be attuned to provide a thrust of 236.5 mN (2411 s) at 6.15 kW of power. While space propulsion is expected to be the prime application for MOA and is supported by numerous applications such as Solar and/or Nuclear Electric Propulsion or even as an ‘afterburner system’ for Nuclear Thermal Propulsion, other terrestrial applications can be thought of as well, making the system highly suited for a common space-terrestrial application research and utilisation strategy. This paper presents the recent developments of the MOA Thruster R&D activities at QASAR (www.qasar.at), the company in Vienna, which has been set up to further develop and test the Alfvén wave technology and its applications. [ABSTRACT FROM AUTHOR]

This paper reports on experimental results from the SLAC NLC accelerator structure closeout program, and discusses a study that was conducted to improve the smoothness of machined tungsten for use in high gradient structures. At the Next Linear Collider Test Accelerator (NLCTA), an X-band (11.424 GHz) structure was operated at a lower temperature to determine whether this would decrease the low rate of breakdowns that still occur after initial processing. Also, various vacuum venting experiments were performed to determine the impact of air, airborne particulates, and oxidation on the performance of a processed accelerator structure. As part of a more long-range high-gradient structure development program, alternative materials to copper are being explored. The CLIC study group at CERN has conducted several accelerator experiments at 30 GHz with structures that have tungsten and molybdenum iris inserts. SLAC has also tested versions of the CLIC 30 GHz design scaled to 11.424 GHz. The results have prompted a tungsten material study directed at exploring new fabrication processes that would provide a cleaner and smoother tungsten surface topography suitable for high gradient applications. A significantly improved tungsten surface finish resulted from this material study, and a single cell X-band cavity containing noses with such tungsten surfaces will be high power tested soon. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Improved understanding of the processes that limit RF electric and magnetic fields at material surfaces is needed to enable development of new accelerator structures that can sustain accelerating fields in the range of 150 MeV/m, and in turn to allow design of a future multi-TeV electron-positron collider. For this purpose, stand-alone RF sources are needed to carry out RF breakdown and pulsed heating studies on test structures of novel design, structures fabricated from a variety of alternate materials, and structures processed using alternate techniques. These new RF sources should operate at frequencies above 11.4 GHz (where high-power klystrons built for NLC are already available), and should incorporate a high-power phase-stable amplifier or harmonic multiplier delivering several 10’s of MW’s of peak power in near-microsecond-long pulses at a repetition rate in the range of 100 Hz. These sources would be operated together with pulse compression systems that can multiply the peak power to 100’s of MW. This paper briefly reviews current performance of the Yale/Omega-P 34-GHz magnicon as a point of departure, and discusses alternative candidates for RF sources at other frequencies. These include a 30-GHz, 50 MW magnicon; and 20.0, 22.8, 34.3, and 45.6 GHz harmonic multipliers. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

In light of the recent developments with the International Linear Collider (ILC), and the recommendation to utilize “Cold” technology for this future particle accelerator, this paper will present the lessons learned from the recently concluded Spallation Neutron Source (SNS) superconducting radio frequency (SRF) cryomodule production run at the Thomas Jefferson National Accelerator Facility (Jefferson Lab). Over the past twenty years Jefferson Lab has worked with industry to successfully design, manufacture, test and commission more SRF cryomodules than any other entity in the United States. The knowledge gained from the design and fabrication of the SNS prototype, eleven — 0.61 (medium) beta and the twelve — 0.81 (high) beta cryomodules, will prove to be an effective asset to the ILC project. After delivery of the final production cryomodule in March 2005, design and fabrication data will be collected, evaluated and presented to make this information beneficial for future particle accelerator projects. Recommendations with respect to these findings will also be presented as an integral part of this paper. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

High Power Proton Accelerators (HPPAs) are studied for several projects based on high-flux neutron sources driven by proton or deuteron beams. Since the front end is considered as the most critical part of such accelerators, the two French national research agencies CEA and CNRS decided to collaborate in 1997 to study and build a High-Intensity Proton Injector (IPHI). The main objective of this project is to master the complex technologies used and the concepts of manufacturing and controlling the HPPAs. Recently, a collaboration agreement was signed with CERN and led to some evolutions in the design and in the schedule. The IPHI design current was maintained at 100 mA in Continuous Wave mode. This choice should allow to produce a high reliability beam at reduced intensity (typically 30 mA) tending to fulfill the Accelerator Driven System requirements. The output energy of the Radio Frequency Quadrupole (RFQ), was reduced from 5 to 3 MeV, allowing then the adjunction and the test, in pulsed operation of a chopper line developed by CERN for the Superconducting Proton Linac (SPL). In a final step, the IPHI RFQ and the chopper line should become parts of the SPL injector. In this paper, the IPHI project and the recent evolutions are reported together with the construction and operation schedule. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Top-up operation was successfully demonstrated at UVSOR-II, which will remove the short beam-lifetime problem caused by strong Touschek effect due to the small emittance, 27 nm-rad, and the low electron energy, 750 MeV. In these years, we have improved the accelerators, step by step, towards top-up operation. The radiation shielding wall was reconstructed. The energy of the booster synchrotron and the beam transport line were successfully upgraded from 600 MeV to 750 MeV, by replacing the magnet power supplies in 2006. Soon after, we succeeded in injecting the electron beam at the full energy. We improved the radiation safety system and constructed a injection control system. In autumn, 2008, we succeeded in operating the ring for 12 hours as keeping the beam current quasi-constant at 300 mA. Currently, we operated the ring in the top-up mode for 12 hours on every Thursday night, to check the effects on the users’ experiments. In 2009, we have succeeded in the top-up operation in single bunch mode. Free electron laser oscillation with the top-up mode was also successfully demonstrated. [ABSTRACT FROM AUTHOR]

In this paper we will discuss experiments performed using an accelerated ion beam incident on selected targets. Some of these were: 1) Measuring Rutherford scattering and/or non-Rutherford nature of scattering as a function of scattering angle, energy of the ion beam and atomic number 2) Verifying theoretical prediction of the kinematical scattering factor by measuring the scattered ion energy 3) Particle Induced X-ray emission (PIXE) and/or Rutherford scattering to determine the elemental thickness and test the theoretical prediction for the x-ray production cross sections. 4) Determination of the mass absorption coefficient of lead using gamma ray spectroscopy 5) Nuclear reaction studies (proton on lithium fluoride) using sodium iodide detector6) Applying X-ray fluorescenceto determine elemental composition. [ABSTRACT FROM AUTHOR]

The design and construction of a plasmoid thruster prototype is described. This thruster operates by expelling pre-detached plasmoids at high velocities. These plasmoids are field reversed configuration plasmas which are formed by reversing a magnetic flux frozen in an ionized gas inside a theta-pinch coil. The pinch coil is a unique multi-turn, multi-lead design chosen for optimization of inductance and field uniformity. The coil is wound around an alumina ceramic core and the operation of the thruster is completely electrode-less. The design of this thruster follows a series of experiments at NASA MSFC based on a single turn theta-pinch coil called the “Plasmoid Thruster Experiment.” Key issues are addressed which affect the efficiency of the PT-1. Testing of this device will begin in FY06 at the NASA MSFC Propulsion Research Center. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

High-intensity proton accelerator complex enabled long baseline neutrino oscillation experiments with a precisely controlled neutrino beam. The beam power so far achieved is a few hundred kW with enourmorous efforts of accelerator physicists and engineers. However, to fully understand the lepton mixing structure, MW-class accelerators are desired. We describe the current intensity-frontier high-energy proton accelerators, their plans to go beyond and technical challenges in the neutrino beamline facilities. [ABSTRACT FROM AUTHOR]

We report a new Accelerator Mass Spectrometry facility at the Physics Institute of Fluminense Federal University in Brazil, the Nuclear Chronology Laboratory—LACRON. The sample preparation laboratory is ready to perform chemical treatment through graphitization and the acquisition of a Single Stage Accelerator Mass Spectrometry System is in progress. LACRON will be the first independent laboratory to perform the 14C-AMS technique not only in Brazil but in Latin America. [ABSTRACT FROM AUTHOR]

Plans to use existing Fermilab facilities to provide beam for the Muon to Electron Conversion Experiment (Mu2e) are under development. The experiment will follow the completion of the Tevatron Collider Run II, utilizing the beam lines and storage rings used today for antiproton accumulation without considerable reconfiguration. The proposed Mu2e operating scenario is described as well as the accelerator issues being addressed to meet the experimental goals. [ABSTRACT FROM AUTHOR]

Ionization cooling will be a key technique for a high-intensity Neutrino Factory or Muon Collider. The Muon Ionization Cooling Experiment (MICE) is a high-precision, staged accelerator experiment being performed at Rutherford Appleton Laboratory in the UK. Its goal is the first demonstration, with 0.1% resolution, of the feasibility of reducing the transverse emittance of a beam of muons by ionization cooling in low-Z absorbers. MICE is being staged in the following steps: I. Creating and characterizing a beam of muons; II. Measuring their emittance; III. Systematic comparison of successive measurements; IV. Inserting absorber; V. Reaccelerating longitudinally; and VI. Complete “10%-cooling” test. Step I is currently in progress with Step II to commence next year; completion of Step VI is anticipated in ∼2012. [ABSTRACT FROM AUTHOR]

Working Group on Accelerator Physics and Machine Design R&D at Nufact-2007 focuses on topics on accelerator physics and technical issues of hardware components associated with a Neutrino Factory or its subsystems. There were 32 presentations given at the working group. A special session was held to discuss collaboration opportunities with the Muon Collider Task Force (MCTF) at Fermilab in consideration of many overlaps in the machine R&D between a Neutrino Factory and a Muon Collider. Two more sessions were held jointly with Working Group 2 on muon collection schemes and other related subjects. [ABSTRACT FROM AUTHOR]

The Japan Proton Accelerator Research Complex (J-PARC) is under construction in Tokai site. The linac beam commissioning started last fall, while the beam commissioning of the 3-GeV Rapid-Cycling Synchrotron (RCS) will start this fall. The status of the J-PARC accelerator is reported with emphasis on the technical development accomplished for the J-PARC. [ABSTRACT FROM AUTHOR]

We describe the Accelerator Mass Spectrometry (AMS) technique and two distinct applications of its use with 14C to study environmental problems in Brazil, such as forest fires and climate changes in the Amazon region and archaeological studies on the early settlements in the Southeast Brazilian coast. [ABSTRACT FROM AUTHOR]

The 11th International Symposium on the Production and Neutralization of Negative Ions and Beams was held in Santa Fe, New Mexico on September 12–15, 2006 and was hosted by Los Alamos National Laboratory. This summary covers the first three oral sessions of the symposium. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

The 11th International Symposium on the Production and Neutralization of Negative Ions and Beams was held in Santa Fe, New Mexico on 13th – 15th September 2006 and was hosted by Los Alamos National Laboratory. This summary covers the sessions of the Symposium devoted to the topics listed in the title. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

The MAX IV light source project is presented. The MAX IV light source will consist of three low emittance storage rings and a 3 GeV injector linac. The three storage rings will be operated at 700 MeV, 1.5 GeV, and 3.0 GeV, which make it possible to cover a large spectral range from IR to hard X-rays with high brilliance undulator radiation from insertion devices optimised for each storage ring. The preparation of the injector linac to serve as a short pulse source and the major sub-systems of the facility are also presented. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

The demagnetization of permanent magnets used in the insertion device, becomes one of the most important issues of the next generation light sources. The demagnetization experiment has been carried out at the electron linac of Pohang Light Source. To find out the mechanism of radiation damage to the magnet, the radiation field around and inside the target and magnet in the experiment is investigated with Monte Carlo code FLUKA (2005 version). The energy spectra of photons and neutrons around the target and magnet are derived and analyzed The 3-dimensional dose distributions in the target and magnet due to 2 GeV incident electrons and secondary particles are also calculated. The calculated results under different target conditions (Cu, Ta target or no target) are compared. Some important parameters such as dose and 1 MeV equivalent fluence are summarized. Finally the demagnetization of the magnet due to radiation at high energy accelerator is discussed. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

Experiments at the LOASIS laboratory of LBNL have demonstrated production of 100 MeV to 1 GeV electron bunches with low energy spread and low divergence from laser wakefield acceleration. The radiation pressure of a 10 TW laser pulse, guided over 10 diffraction ranges by a few-mm long plasma density channel, was used to drive an intense plasma wave (wakefield), producing electron bunches with energies on the order of 100 MeV and acceleration gradients on the order of 100 GV/m. Beam energy was increased from 100 MeV to 1 GeV by using a few-cm long guiding channel at lower density, driven by a 40 TW laser, demonstrating the anticipated scaling to higher beam energies. Particle simulations indicate that the low energy spread beams were produced from self-trapped electrons through the interplay of trapping, loading, and dephasing. Other experiments and simulations are also underway to control injection of particles into the wake, and hence improve beam quality and stability further. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

A summary is given of presentations and discussions in the Laser-Plasma Acceleration Working Group at the 2006 Advanced Accelerator Concepts Workshop. Presentation highlights include: widespread observation of quasi-monoenergetic electrons; good agreement between measured and simulated beam properties; the first demonstration of laser-plasma acceleration up to 1 GeV; single-shot visualization of laser wakefield structure; new methods for measuring < 100 fs electron bunches; and new methods for “machining” laser-plasma accelerator structures. Discussion of future directions includes: developing a roadmap for laser-plasma acceleration beyond 1 GeV; a debate over injection and guiding; benchmarking simulations with improved wake diagnostics; petawatt laser technology for future laser-plasma accelerators. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

The effects of radiation reaction on electron beam dynamics are studied in the context of plasma-based accelerators. Electrons accelerated in a plasma channel undergo transverse betatron oscillations due to strong focusing forces. These oscillations lead to emission by the electrons of synchrotron radiation, with a corresponding energy loss that affects the beam properties. An analytical model for the single particle orbits and beam moments including the classical radiation reaction force is derived and compared to the results of a particle transport code. It is shown that the radiation could significantly affect the beam properties (e.g., increased relative energy spread) in plasma wakefield accelerators. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

A proof of principle experiment is underway at the UCLA Neptune laboratory to test the concept of generating linearly ramped relativistic electron bunches (rising in density from head to tail followed by a sharp cutoff) by using a sextupole-corrected dogleg section as a bunch compressor. Bunches with this structure have been predicted to be ideal for use as a plasma wake-field drive beam. The diagnostic being developed to measure the time profile of the beam is an X-Band (9.6 GHz) deflecting cavity. The recently completed cavity is a 9-cell standing wave structure operating in a TM110-like mode, designed to measure the temporal structure of the 2 to 10 ps, 14 MeV electron bunches generated by the Neptune S-band photoinjector and plane-wave transformer (PWT) accelerator beamline, with 50 fs resolution. We discuss the experimental plan for the ramped bunch experiment and present preliminary data related to the tuning and operation of the deflecting cavity. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

We propose a Compton gamma-source for generating a polarized positron beam for the next generation of electron-positron colliders, such as the International Linear Collider (ILC) and the Compact Linear Collider (CLIC). This 40-MeV polarized gamma-source is based on inverse Compton scattering inside a picosecond CO2 laser cavity from electron bunches produced by a 4-GeV linac. In a separate experiment, we identified and experimentally verified the optimum conditions for generating one gamma photon per every electron. After multiplication at several consecutive interaction points, the gamma-rays so produced will be stopped on a target, thereby creating a copious numbers of circularly polarized positrons. We address the practical feasibility of having an intra-cavity Compton polarized positron source as the injector for these new colliders. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Using higher-order transverse laser modes for plasma wakefield excitation, and, in particular, shaping a ring beam with maximum intensity off-axis, results in shifting the focusing and defocusing phase regions of a plasma wakefield accelerator. This results in a decreased trapping threshold required for electron injection and an increase of the maximum electron energy. This scheme could also be of interest as a method for generating ring electron beams. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

A rectangular dielectric-lined metallic structure was studied that has an advantage over a cylindrical structure from the possibility of exciting by a sequence of bunches many equally-spaced modes, thereby building up a larger mode-locked wakefield. A rectangular vacuum copper waveguide was lined with two dielectric slabs, the size of which was calculated to provide resonant excitation of the fundamental LSM mode by a sequence of bunches with repetition frequency f0=2805 MHz, produced by linear resonant electron accelerator (4.5 MeV, number of bunches 6.103, diameter 1cm, duration 60 ps each, distance between bunches 300 ps, number of electrons in each bunch 109). The waveguide has cross section 85 mm × 180 mm, and Teflon ([variant_greek_epsilon] = 2.1) plates were placed along the smaller sides of the waveguide, their thickness from the calculation being 22 mm. In experiments, the length of the resonator was 535mm. We found that the total wakefield is three times larger than the fundamental mode; thus a greater number of excited modes was excited compared with the cylindrical case, for which this ratio was only 1.5. We found considerably more energy loss of electron bunches for the resonator case compared with the waveguide case. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]