Instrumentation

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RPAP043 Beam-Based Alignment in the RHIC eCooling Solenoids 2771
 
  • P. Cameron, I. Ben-Zvi, W.C. Dawson, J. Kewisch, V. Litvinenko, Y. Luo, W.W. MacKay, C. Montag, J. Niedziela, V. Ptitsyn, T. Satogata, C. Schultheiss, V. Yakimenko
    BNL, Upton, Long Island, New York
 
  Funding: U.S. DOE.

Accurate alignment of the electron and ion beams in the RHIC electron cooling solenoids is crucial for well-optimized cooling. Because of the greatly differing rigidities of the electron and ion beams, to achieve the specified alignment accuracy it is required that transverse magnetic fields resulting from imperfections in solenoid fabrication be down by five orders of magnitude relative to the pure solenoid fields. Shimming the solenoid field to this accuracy might be accomplished by survey techniques prior to operation with beam, or by methods of beam-based alignment. We report on the details of a method of beam-based alignment, as well as the results of preliminary measurements with the ion beam at RHIC

 
RPAP044 Linearizing the Response of the NSRL Synchronous Recycling-Integrators 2830
 
  • P. Oddo, A. Rusek, T. Russo
    BNL, Upton, Long Island, New York
 
  Funding: Work performed under the auspices of the U.S. Department of Energy.

The LBNL designed recycling-integrators used for the NSRL dosimetry feature excellent linearity. However, switching transients in the balancing source add a duty-cycle dependence to the response that manifests as a non-linearity near mid-scale and a slope-change above mid-scale. The onset of this non-linearity limits the typical usable dynamic range. Measurements during a recent run showed that at higher intensities the recycling-integrators would operate in the non-linear region enough to exceed the desired tolerance and over count the dose. This report will show how a FPGA, which implements the scalars, was used to compensate the non-linearity allowing higher dose-rates by effectively doubling the dynamic range of the dosimetry system.

 
RPAP045 Development of Laser-Induced Fluorescence Diagnostic for the Paul Trap Simulator Experiment 2878
 
  • M. Chung, R.C. Davidson, P. Efthimion, E.P. Gilson, R. M. Majeski, E. Startsev
    PPPL, Princeton, New Jersey
 
  Funding: Research Supported by the U.S. Department of Energy.

The Paul Trap Simulator Experiment (PTSX) is a cylindrical Paul trap whose purpose is to simulate the nonlinear dynamics of intense charged particle beam propagation in alternating-gradient magnetic transport systems. For the in-situ measurement of the transverse ion density profile in the PTSX device, which is essential for the study of beam mismatch and halo particle production, a laser-induced fluorescence diagnostic system is being developed. Instead of cesium, which has been used in the initial phase of the PTSX experiment, barium has been selected as the preferred ion for the laser-induced fluorescence diagnostic. The installation of the barium ion source and the characterization of the tunable dye laser system are discussed. The design of the collection optics with an intensified CCD camera system is also discussed. Finally, initial test results using the laser-induced fluorescence diagnostic will be presented.

 
RPAP046 Real-Time Beam Loss Monitor Display Using FPGA Technology 2914
 
  • M.R.W. North, A.H. Kershaw
    CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
 
  This paper outlines the design of a Real-time Beam Loss Monitor Display for the ISIS Synchrotron based at Rutherford Appleton Laboratory (Oxon, UK). Beam loss is monitored using 39 argon filled ionisation chambers positioned around the synchrotron, the levels of which are sampled four times in each cycle. The new BLM display acquires the signals and displays four histograms, each relating to an individual sample period; the data acquisition and signal processing required to build the display fields are completed within each machine cycle (50 Hz). Attributes of the new system include setting limits for individual monitors; displaying over-limit detection, and freezing the display field when a beam trip has occurred. The design is based around a reconfigurable Field Programmable Gate Array, interfacing to a desktop monitor via the VGA standard. Results gained using simulated monitor signals have proven the system.  
RPAP047 DAQ System of BPM and BCT for the BEPCII Linac 2980
 
  • J. Cao, Q. Ye
    IHEP Beijing, Beijing
 
  Following the BEPCII upgrade, total about 19 BPM and 12 BCT have been newly installed in the BEPCII Linac. Also, a set of distributed control system based on EPICS architecture has been built, and the BPM and BCT system are merged into the new control system for the data acquisition. In order to reduce the effects of RF noise, a special gated integrator was used to measure the beam current. In this paper we will describe the DAQ system of BPM and BCT including calibrations in detail.  
RPAP048 SNS Diagnostics Timing Integration 3001
 
  • C.D. Long
    Innovative Design, Knoxville, Tennessee
  • W. Blokland, D.J. Murphy, J. Pogge, J.D. Purcell
    ORNL, Oak Ridge, Tennessee
  • M. Sundaram
    University of Tennessee, Knoxville, Tennessee
 
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy.

The Spallation Neutron Source (SNS) accelerator systems will deliver a 1.0 GeV, 1.4 MW proton beam to a liquid mercury target for neutron scattering research. The accelerator complex consists of a 1 GeV linear accelerator, an accumulator ring and associated transport lines. The SNS diagnostics platform is PC-based running Windows XP Embedded for its OS and LabVIEW as its programming language. Coordinating timing among the various diagnostics instruments with the generation of the beam pulse is a challenging task that we have chosen to divide into three phases. First, timing was derived from VME based systems. In the second phase, described in this paper, timing pulses are generated by an in house designed PCI timing card installed in ten diagnostics PCs. Using fan-out modules, enough triggers were generated for all instruments. This paper describes how the Timing NAD (Network Attached Device) was rapidly developed using our NAD template, LabVIEW’s PCI driver wizard, and LabVIEW Channel Access library. The NAD was successfully commissioned and has reliably provided triggers to the instruments. This work supports the coming third phase where every NAD will have its own timing card.

 
RPAP049 Beam Diagnostics with Optical Fiber Optics 3040
 
  • Y. Yin
    Y.Y. Labs, Inc., Fremont, California
 
  Optical fiber has been widely used for communications. It is a waveguide with very high-frequency bandwidth. Therefore, it has broad applications for high-frequency related signals such as high-energy Accelerator beam signls. Research and developments has been done to measure charged particle beam and synchrotron radiation with optical fiber based instruments developed by the author. The paper will describe and discuss the experiments and testing of charged particle beams and synchrotron radiation that haverecently been performed.  
RPAT098 Phase-Space Dynamic Tracking by a Two Pickups Data Acquisition System 4326
 
  • A. Drago, M.E. Biagini, S. Guiducci, C. Milardi, M.A. Preger, C. Vaccarezza, M. Zobov
    INFN/LNF, Frascati (Roma)
 
  A two pickups dynamic tracking data acquisition system has been developed at LNF for the DAFNE Phi-factory. Two oscilloscopes sample horizontal and vertical sum and difference signals from two pickups simultaneously; the sampling clock is locked to the DAFNE timing system. A horizontal kick excites the beam motion and initiates the acquisition. Turn-by-turn signals are converted to beam position and stored on a server in a database using timestamp labels. Oscillation amplitude versus time, phase space distribution and frequency domain analysis are shown for several lattices and different settings of sextupoles and octupoles. Results are used to check the DAFNE non-linear model.  
RPAT100 Radiation-Hard Beam Position Detector for Use in the Accelerator Dump Lines 4341
 
  • P. Degtiarenko, D.W. Dotson, V.P. Popov
    Jefferson Lab, Newport News, Virginia
 
  Funding: This work supported by the U.S. Department of Energy under contract DE-AC05-84ER40150

The new proposed method of beam position measurement is particularly suitable for monitoring high energy, and high power accelerated beams of charged particles in the vicinity of power beam dumps. Generally, the beam quality in those areas is very poor, and any equipment positioned there must be extremely resistant to radiation damage. We have found that a plate made of Chemical Vapor Deposition (CVD) Silicon Carbide (SiC) has a set of physical properties that make it suitable for such an application. CVD SiC material is a chemically inert, extremely radiation-hard, thermo-resistive semiconductor capable of withstanding working temperatures up to 2000 degrees Kelvin. It has good thermal conductivity comparable to that of Aluminum, which makes it possible to use it in high-current particle beams. High electrical resistivity of the material, and its semiconductor properties allow characterization of the position of a particle beam crossing such a plate by measuring balance of electrical currents at the plate ends. The design of a test device, and first results are presented in the report.