LANL, Los Alamos, New Mexico
TechSource, Santa Fe, New Mexico
Recent beam studies have focused on understanding the main sources and locations of electron clouds (EC) which drive the observed e-p instability at the PSR. New results using a recently developed electron diagnostic will be reported which demonstrate the important role of EC activity in quadrupole magnets, including definitive evidence that ~80% or more of the drift space EC signal is “seeded” by electrons ejected by ExB drifts from adjacent quadrupole magnets*. Other observations include distinctive brown colored tracking in various dipole and quadrupole vacuum chambers, which we hypothesize is caused by energetic electrons striking the wall during beam-induced multipacting. The tracking observations point to a simple and useful signature for regions of EC activity. Modeling of EC observations using a modified version of the POSINST** code shows general agreement on many features of the observations, given the large uncertainties in the distribution of seed electrons from beam loss which is a key input into the simulations. Progress will be reported on resolving the features not in agreement.
* R. Macek et al, PRSTAB, 11, 010101 (2008).
** M. T. F. Pivi and M. A. Furman, PRSTAB, 6, 034201 (2003).
ORNL, Oak Ridge, Tennessee
The paper describes a parallel flow of the Spallation Neutron Source (SNS) linac and ring commissioning and development of commissioning tools. An evolution of the physics control system, its features, problems and solutions are presented. The peculiarities of the SNS project such as a collaboration between six Department of Energy laboratories, an absence of previous experience in large accelerator construction and operation in Oak Ridge National Laboratory, an original upper level of a control system (physics applications) and their effect on SNS commissioning are discussed. SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy.
Fermilab, Batavia, Illinois
High intense hadron beams of > 2 MW beam power are a key element for the new proposed Neutrino experiments at Fermilab. Therefore a new beam facility, called Project-X, is under discussion. We will present requirements, and first conceptual ideas for beam instrumentation and diagnostics, and the related R&D initiatives taking place in the high intense test accelerators, currently under construction. First results of beam profile measurements using OTR screens and laser wires are shown.
Fermilab, Batavia, Illinois
The FNAL Booster Accelerator delivers about 1017 8 GeV protons/hour. The Booster present cycling rate is 8 Hz but can go as high as 10 Hz with plans to run at 15 Hz. Booster's current operations and future plans required upgrades to most of Booster 30 year old diagnostic hardware and software. Beam quality as well as beam intensity and cycle repetition rate first became an issue when the neutrino experiment BooNE started in 2002. Since then MI slip stacking and continuation of running to MiniBooNE continues to push Booster diagnostics and software upgrades. Control of residual radiation while increasing the Booster throughput over 10 fold has been successful but the work is not done.
STFC/RAL, Chilton, Didcot, Oxon
STFC/RAL/ISIS, Chilton, Didcot, Oxon
STFC/RAL/ASTeC, Chilton, Didcot, Oxon
Imperial College of Science and Technology, Department of Physics, London
In order to contribute to the development of high power proton accelerators in the MW range a front end test stand (FETS) is being constructed at the Rutherford Appleton Laboratory (RAL) in the UK. The aim of the FETS is to demonstrate the production of a 60 mA, 2 ms, 50 pps chopped beam at 3 MeV with sufficient beam quality. Therefore a comprehensive set of diagnostic tools have been developed or are in the design and construction phase. To improve the beam quality delivered by the Penning H- ion source using a slit extraction, a pepper pot emittance measurement device and a 2D-transversal profile scanner has been built and used on the ion source development rig and results of the beam measurements will be presented. As destructive diagnostic devices suffer from the high beam power deposited on the device surfaces, two new diagnostic devices based on the photo detachment principle are under construction: A laser wire scanner allowing the reconstruction of the full 2D-transversal density distribution using tomographic techniques and an emittance scanner device. The design and status of construction of both devices will be presented and new ideas for the data analyses discussed.
CIEMAT, Madrid
CEA, Gif-sur-Yvette
The IFMIF-EVEDA accelerator will be a 9 MeV, 125 mA CW deuteron accelerator which aims to validate the technology that will be used in the future IFMIF accelerator. It is essential then to implement the necessary instrumentation for the commissioning and operation of the accelerator prototype, as well as for a correct characterization of the beam properties. A set of instrumentation will be installed in the last part of the accelerator, at the first section of the High Energy Beam Transport Line (HEBT), between the superconducting HWR and the Beam Dump (BD), in the so-called Diagnostics Plate (DP) to fully characterize the beam properties both from the RFQ and the HWR. In addition, there will be dedicated diagnostics all along the HEBT to transport and control the beam safely down to the BD. Moreover, the closest area to the BD with high radiation levels and big pipe aperture- can be used for the tests of IFMIF profilers. In this contribution the requirements imposed by the high-intensity deuteron accelerator to the instrumentation along the HEBT, the type of techniques that will be used and a preliminary layout and specifications of the diagnostics in the line will be presented.
STFC/RAL/ISIS, Chilton, Didcot, Oxon
ISIS is the spallation neutron source based at the Rutherford Appleton Laboratory in the UK. There are currently 227 individual diagnostic devices distributed between the 70MeV Linac, the 800MeV accelerator ring and the two target beam lines (TS1, TS2). This paper summaries the current state of the ISIS diagnostic systems and describes how the various diagnostics are used to tune the machine, to monitor beam intensity and beam losses and to provide fast machine protection. The limitations and accuracy of the various diagnostic systems (e.g. spatial and energy resolution, sensitivity, speed) are explored along with the steps that are being carried out to tackle any shortcomings. This paper will also briefly look at the new PXI based data acquisition and diagnostic control electronics used on ISIS and the problems encountered in using these systems within radiation environments.
ORNL, Oak Ridge, Tennessee
Charged-particle beam diagnostic devices such as wire scanners and wire harps provide data sets describing the one-dimensional density distributions at a particular location; these data are commonly called profile data. We use these data for further computations, usually beam properties such as position and size. Typically these data require subjective, human, processing to extract meaningful results; this is inefficient and labor intensive. Our ultimate goal is to automate these computations, at least streamline the process. If we hope to implement any type of automation we must make real world considerations. Specifically, we consider information content, noise in the data, and sampling theory. Within this framework we create a general model for the data sets. Using signal processing techniques we identify the minimal sampling requirements for maintaining information content. Using Bayesian analysis we identify the most probable Gaussian signal within the data. We present the major obstacles currently faced concerning robust automation techniques.
Fermilab, Batavia, Illinois
KEK, Ibaraki
Working group F was charged with presentations and discussions on diagnostics and instrumentation of highintensity beams. We had 3 sessions spanning a total time of 330 minutes, in which 13 talks were presented. The presentation time for each talk had to be limited to 15-20 min., in order to allow sufficient time (5-10 min.) for some discussion. This turned out quite well, even though some presentations went longer, not every topic required the anticipated discussion time.
A final discussion session of 110 minutes was held as joint session with working group D (operations).