TUPOA —  Poster Session (MC6 & MC8)   (11-Oct-16   08:30—12:30)
Paper Title Page
TUPOA04 Study on THz Imaging by Using the Coherent Cherenkov Radiation 296
 
  • M. Nishida, M. Brameld, M. Washio
    Waseda University, Tokyo, Japan
  • R. Kuroda, Y. Taira
    AIST, Tsukuba, Ibaraki, Japan
  • K. Sakaue
    Waseda University, Waseda Institute for Advanced Study, Tokyo, Japan
  
  THz frequency is a special electromagnetic wave which is categorized between a radio wave and a light wave. It can pass through the various materials like a radio wave and can be transported with optical components like a light wave. Thus, it's suitable for imaging application of materials. At Waseda University, it's possible to generate a high-quality electron beam using Cs-Te photocathode RF-Gun and the electron beam is applied to several application researches. As an application of this electron beam, we generate a coherent Cherenkov radiation, and succeed in observing a high power THz light. The successful results of high power THz radiation encourage us to perform the THz imaging with transmission and reflection imaging using some materials, cross-section imaging using a simple material. On studying the THz imaging, it is necessary to clarify the spatial resolution. So, we tried to evaluate the spatial resolution in our device. Furthermore, our target is to get the three-dimensional THz images. We will introduce the CT technique in order to obtain the clear cross-section image. In this conference, we report the recent results of the THz imaging and future prospective.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA04  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA05 Development of a Fiber Laser for Improving the Pulse Radiolysis System 299
SUPO37   use link to see paper's listing under its alternate paper code  
 
  • Y. Saito, S.Y. Soeta, M. Washio
    Waseda University, Tokyo, Japan
  • Y. Hosaka, K. Sakaue
    RISE, Tokyo, Japan
  
  When material is irradiated by the ionizing radiation, short-lived and highly reactive substance intermediate active species are made and then react with substances. The chemical reaction is determined by intermediate active species in early process. Proving the behavior of intermediate active species is important for understanding and controlling radiation chemical reaction. In Waseda university we been developing a Pulse Radiolysis System, a method to measure the behavior of intermediate species, for radiation chemical analysis with RF electron gun. Currently we are developing a Supercontinuum ray(SC ray)as a probe ray to improve Pulse Radiolysis System. We have introduced a SC ray using Yb fiver laser and PCF(Photonic Crystal Fiber). But this type of prove light isn't stable enough in the visible light region. Therefore we started to study Er fiber laser oscillator as new prove ray source. We have succeeded to oscillate a Er fs laser pulse, second harmonic generation and measurement of hydrated electron in ns time resolution. In this presentation we will report current research about generation of SC ray, Er fiber laser system and dose rate effect against the hydrated electron.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA05  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA07 IoT Application in the Control System of the BEPCII Power Supplies 302
 
  • C.H. Wang, L.F. Li, X.L. Wang
    IHEP, Beijing, People's Republic of China
  • C.P. Chu
    MSU, East Lansing, Michigan, USA
  
  Funding: This prject is support by NSFC(1137522)
In recent years in the development of Internet technology, the Internet of things (IoT) has begun to apply to each domain. The paper introduces the idea how to apply IoT to the accelerator control system and take the existing control system of the BEPCII power supplies as an example for IoT application. It not only introduce the status of the control system of the BEPCII power supplies, but also present a solution how to apply IoT to the existing control system. The purpose is to make the control system more intelligent and automatically identify what and where problem when the alarm of the control system of the power supplies. That means that IoT can help to automatically identify which crate and which PSC board inserted in the crates and which PSI sittiing in the power supply crates as well as the optic fiber cables between the PSCs and the PSIs. It is great convenient for the maintainer to use a mobile phone to diagnose faults and create the electronic maintenance record. 		 
poster icon Poster TUPOA07 [0.762 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA07  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA10 Cyclotrons for Accelerator-Driven Systems 305
 
  • T.-Y. Lee, J. Lee, S. Shin
    PAL, Pohang, Kyungbuk, Republic of Korea
  • C.U. Choi, M. Chung
    UNIST, Ulsan, Republic of Korea
  
  Accelerator-Driven system (ADS) can transmute long lived nuclear waste to short lived species. For this system to be fully realizable, a very stable high energy and high power proton beam (typically, 1 GeV beam energy and 10 MW beam power) is required, and preparing such a powerful and stable proton beam is very costly. Currently, the most promising candidate is superconducting linear accelerators. However, high power cyclotrons may be used for ADS particularly at the stage of demonstrating proof of principle of ADS. This paper discusses how cyclotrons can be used to demonstrate ADS.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA10  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA12 An Updated LLRF Control System for the TLS Linac 308
 
  • C.Y. Wu, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, K.H. Hu, D. Lee, C.Y. Liao
    NSRRC, Hsinchu, Taiwan
  
  The amplitude and phase of the RF field at the linear accelerator (LINAC) decides the beam quality. To study and to improve the performance of the LINAC system for Taiwan Light Source (TLS), a new design of a low-level radio-frequency (LLRF) control system was developed and set up for the TLS LINAC. The main components of the LLRF control system are an I/Q modulator, an Ethernet-based arbitrary waveform generator, a digital oscilloscope and an I/Q demodulator; these are essential parts of the LLRF feed-forward control. This paper presents the efforts to improve the LLRF control system. The feasibility of the RF feed-forward control will be studied at the linear accelerator of TLS.  
poster icon Poster TUPOA12 [1.425 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA12  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA13 First Test Run for High Density Material Imaging Experiment Using Relativistic Electron Beam at the Argonne Wakefield Accelerator 311
SUPO49   use link to see paper's listing under its alternate paper code  
 
  • Y.R. Wang
    AAI/ANL, Argonne, Illinois, USA
  • S. Cao, X.K. Shen, Z.M. Zhang, Q.T. Zhao
    IMP/CAS, Lanzhou, People's Republic of China
  • M.E. Conde, D.S. Doran, W. Gai, W. Liu, J.G. Power, J.Q. Qiu, C. Whiteford, E.E. Wisniewski
    ANL, Argonne, Illinois, USA
  
  A test facility, AWA, has been commissioned and in operation since last year. It can provide beam of several bunches in a train of nano-seconds and 10s of nC with energy up to 70 MeV. In addition, the AWA can accommodate various beamlines for experiments. One of the proposed experiments is to use the AWA beam as a diagnostics for time resolved high density material, typically a target with high Z and time dependent, imaging experiments. When electron beam scatters after passing through the target, and the angular and energy distribution of beam will depend on the density and thickness of the target. A small aperture is used to collimate the scattered electron beam for off axis particles, and the target image will be detected by imaging plate. By measuring the scatted angle and energy at the imaging plate would yield information of the target. In this paper, we report on the AWA electron imaging (EI) system setup, which consist of a target, imaging optics and drift transport. The AWA EI beam line was installed on June, 2016 and the first test run was performed on August, 2016. This work will have implication on the high energy density physics and even future nuclear fusion studies.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA13  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA14 An Internet Rack Monitor-Controller for APS LINAC RF Electronics Upgrade 314
 
  • H. Ma, A. Nassiri, T.L. Smith, Y. Sun
    ANL, Argonne, Illinois, USA
  • L.R. Doolittle, A. Ratti
    LBNL, Berkeley, California, USA
  
  Funding: Work supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences
To support the current 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, rack-mount digital electronics platform 'Internet Rack Monitor-Controller (or IRMC) to replace the existing analog ones on the legacy crate/backplane-based hardware. The system model of the envisioned IRMC is basically a 3-tier stack with a high-performance processor in the mid- layer to handle the general digital signal processing (DSP). The custom FPGA IP's in the bottom layer handle the high-speed, real-time, low-latency DSP tasks, and provide the interface ports. A network communication gateway, in conjunction with an embedded event receiver (EVR), in the top layer merges the Internet Rack Monitor-Controller device 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 accelerators for over two decades. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA14  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA16 A VME and FPGA Based Data Acquisition System for Intensity Monitors 317
 
  • J.S. Diamond, A. Ibrahim, N. Liu, E.S.M. McCrory, A. Semenov
    Fermilab, Batavia, Illinois, USA
  
  Funding: Operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the United States Department of Energy
A universal data acquisition system supporting toroids, DCCTs, Faraday cups, srapers and other types of instru-mentation has been developed for reporting beam inten-sity measurements to the Fermilab Accelerator Controls System (ACNet). Instances of this front end, supporting dozens of intensity monitor devices have been deployed throughout the Fermilab accelerator complex in the Main Injector, Recycler, Fermilab Accelerator Science and Technology (FAST) facility and the PIP-II Injector Exper-iment (PXIE). Each front end consists of a VME chassis containing a single board computer (SBC), timing and clock module and one or more 8 to 12-channel digitizer modules. The digitizer modules are based on a Cyclone III FPGA with firmware developed in-house allowing a wide range of flexibility and digital signal processing capability. The front end data acquisition software adds a list of new features to the previous generation allowing users to: take beam intensity measurements at custom points in the acceleration cycle, access waveform data, control machine protection system (MPS) parameters and calculate beam energy loss.

 
poster icon Poster TUPOA16 [1.532 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA16  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA17 A Longitudinal Digital Mode Damper System for the Fermilab Booster 320
 
  • N. Eddy, W. Pellico, A. Semenov, D.C. Voy, A.M. Waller
    Fermilab, Batavia, Illinois, USA
  
  Funding: This work was supported by the U.S. Department of Energy under contract No. DE-AC02-07CH11359.
The Fermilab Booster accelerates bunches and accelerates proton beams from 400 MeV to 8 GeV. During the acceleration the Radio Frequency (RF) cavities are swept from 38MHz to 52.8MHz and requires crossing through transition where accelerating phase is shifted 90 degrees. In order to keep the beam stable and minimize losses and emittance growth a longitudinal damping system is required. This has traditionally been done by dedicated analog electronics designed to operate on specific beam modes for frequencies of instabilities. A complete digital implementation has been developed for this same purpose. The new digital system features and performance are detailed. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA17  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA18 Low Level RF Control for the PIP-II Injector Test RFQ 323
 
  • J.P. Edelen, B.E. Chase, E. Cullerton, J. Einstein, P. Varghese
    Fermilab, Batavia, Illinois, USA
  
  The PIP-II injector test radio frequency quadrupole (RFQ) arrived at Fermilab in the fall of 2015. The RFQ is a 162.5MHz H− accelerator with a nominal drive power of 100kW, which produces a bunched H− beam at 2.1MeV. In this paper we discuss commissioning, operational performance, and improvements to the low level RF (LLRF) control system for the RFQ. We begin by describing the general system configuration and initial simulation results. We will then highlight temperature related issues in the high power RF system, which necessitate active control over the phase balance of the two amplifiers. Finally we demonstrate performance of the RF feedback and feed-forward compensation needed to meet specification during a 20-microsecond beam pulse.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA18  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA19 50-MeV Run of the IOTA/FAST Electron Accelerator 326
 
  • D.R. Edstrom, C.M. Baffes, C.I. Briegel, D.R. Broemmelsiek, K. Carlson, B.E. Chase, D.J. Crawford, E. Cullerton, J.S. Diamond, N. Eddy, B.J. Fellenz, E.R. Harms, M.J. Kucera, J.R. Leibfritz, A.H. Lumpkin, D.J. Nicklaus, E. Prebys, P.S. Prieto, J. Reid, A.L. Romanov, J. Ruan, J.K. Santucci, T. Sen, V.D. Shiltsev, Y.-M. Shin, G. Stancari, J.C.T. Thangaraj, R.M. Thurman-Keup, A. Valishev, A. Warner, S.J. Wesseln
    Fermilab, Batavia, Illinois, USA
  • A.T. Green
    Northern Illinois Univerity, DeKalb, Illinois, USA
  • A. Halavanau, D. Mihalcea, P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
  • J. Hyun
    Sokendai, Ibaraki, Japan
  • P. Kobak
    BYU-I, Rexburg, USA
  • W.D. Rush
    KU, Lawrence, Kansas, USA
  
  Funding: Supported by the DOE contract No.DEAC02-07CH11359 to the Fermi Research Alliance LLC.
The low-energy section of the photoinjector-based electron linear accelerator at the Fermilab Accelerator Science & Technology (FAST) facility was recently commissioned to an energy of 50 MeV. This linear accelerator relies primarily upon pulsed SRF acceleration and an optional bunch compressor to produce a stable beam within a large operational regime in terms of bunch charge, total average charge, bunch length, and beam energy. Various instrumentation was used to characterize fundamental properties of the electron beam including the intensity, stability, emittance, and bunch length. While much of this instrumentation was commissioned in a 20 MeV running period prior, some (including a new Martin-Puplett interferometer) was in development or pending installation at that time. All instrumentation has since been recommissioned over the wide operational range of beam energies up to 50 MeV, intensities up to 4 nC/pulse, and bunch structures from ~1 ps to more than 50 ps in length. 		 
poster icon Poster TUPOA19 [4.636 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA19  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA24 Beam Intensity Monitoring System for the PIP-II Injector Test Accelerator 330
 
  • N. Liu, J.S. Diamond, N. Eddy, A. Ibrahim, N. Patel, A. Semenov
    Fermilab, Batavia, Illinois, USA
  
  Funding: This work was supported by the U.S. Department of Energy under contract No. DE-AC02-07CH11359.
The PIP-II injector test accelerator is an integrated systems test for the front-end of a proposed CW-compatible, pulsed H− superconducting RF linac. This linac is part of Fermilab's Proton Improvement Plan II (PIP-II) upgrade. This injector test accelerator will help minimize the technical risk elements for PIP-II and validate the concept of the front-end. Major goals of the injector accelerator are to test a CW RFQ and H− source, a bunch-by-bunch MEBT beam chopper and stable beam acceleration through low-energy superconducting cavities. Operation and characterization of this injector places stringent demands on the types and performance of the accelerator beam diagnostics. This paper discusses the beam intensity monitor systems as well as early commissioning measurements of beam transport through the Medium-Energy Beam Transport (MEBT) beamline. 		 
poster icon Poster TUPOA24 [1.039 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA24  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA25 Initial Demonstration of 9-MHz Framing Camera Rates on the FAST Drive Laser Pulse Trains* 333
 
  • A.H. Lumpkin, D.R. Edstrom, J. Ruan
    Fermilab, Batavia, Illinois, USA
  
  Funding: * Work at Fermilab supported by Fermi Research Alliance, LLC under Contract No. DE-AC02- 07CH11359 with the United States Department of Energy.
Although beam centroid information at the MHz-micropulse-repetition rate has routinely been achieved at various facilities with rf BPMS, the challenge of recording beam size information at that rate is more daunting. The Integrable Optics Test Accelerator (IOTA) ring being planned at Fermilab has ~8 MHz revolution rates. To simulate the IOTA synchrotron radiation source temporal structure, we have used the UV component of the drive laser of the Fermilab Accelerator Science and Technology (FAST) Facility. This laser is normally set at 3 MHz, but has also been run at 9 MHz. We have configured our Hamamatsu C5680 streak camera in a framing camera mode using a slow vertical sweep plugin unit with the dual axis horizontal sweep unit**. A two-dimensional array of images sampled at the MHz rate can then be displayed on the streak tube phosphor and recorded by the CCD readout camera at up to 10 Hz. As an example, by using the 10 microsecond vertical sweep with the 100 microsecond horizontal sweep ranges, 49 of the 300 micropulses at 3 MHz are displayed for a given trigger delay in each of six images. Example 2D image arrays with profiling examples will be presented.
**Hamamatsu C5680 product web page. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA25  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA26 Initial Observations of Micropulse Elongation of Electron Beams in a SCRF Accelerator* 337
 
  • A.H. Lumpkin, D.R. Edstrom, J. Ruan, J.K. Santucci, R.M. Thurman-Keup
    Fermilab, Batavia, Illinois, USA
  
  Funding: * Work at Fermilab supported by Fermi Research Alliance, LLC under Contract No. DE-AC02- 07CH11359 with the United States Department of Energy
Commissioning at the SCRF accelerator at the Fermilab Accelerator Science and Technology (FAST) Facility has included the implementation of a versatile bunch-length monitor located after the 4-dipole chicane bunch compressor for electron beam energies of 20-50 MeV and integrated charges in excess of 10 nC. The team has initially used a Hamamatsu C5680 synchroscan streak camera. An Al-coated Si screen was used to generate optical transition radiation (OTR) resulting from the beam's interaction with the screen. The chicane bypass beamline allowed the measurements of the bunch length without the compression stage at the downstream beamline location using OTR and the streak camera. The UV component of the drive laser had previously been characterized with a Gaussian fit σ of 3.5-3.7 ps**. However, the uncompressed electron beam is expected to elongate due to space charge forces in an initial 1.5-m drift from the gun to the first SCRF accelerator cavity. We have observed electron beam bunch lengths from 5 to 14 ps (σ) for micropulse charges of 60 pC to 800 pC, respectively. Commissioning of the system and initial results with uncompressed and compressed beam will be presented.
**A.H. Lumpkin et al., Proceedings of FEL14, MOP021, Basel, Switzerland, www. JACoW.org 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA26  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA27 From Relativistic Electrons to X-ray Phase Contrast Imaging 341
 
  • A.H. Lumpkin
    Fermilab, Batavia, Illinois, USA
  • M.A. Anastasio, A.B. Garson
    Washington University in St. Louis, St. Louis, Missouri, USA
  
  Funding: Work at Fermilab partly supported by Fermi Research Alliance, LLC under Contract No.DE-AC02-07CH11359 with the U.S.DoE. Work at Washington Univ. in St. Louis was supported in part by NSF CBET1263988.
X-ray phase contrast (XPC) imaging is an emerging technology that holds great promise for biomedical applications due to its ability to provide information about soft tissue structure *. The need for high spatial resolution at the boundaries of the tissues is noted for this process. Based on results from imaging of relativistic electron beams with single crystals **, we proposed transferring single-crystal imaging technology to this bio-imaging issue. Using a microfocus x-ray tube (17 kVp) and the exchangeable phosphor feature of the camera system, we compared the point spread function (PSF) of the system with the reference P43 phosphor to that with several rare earth garnet single crystals of varying thickness. Based on single Gaussian peak fits to the collimated x-ray images, we observed a four times smaller system PSF (21 microns (FWHM)) with the 25-mm diameter single crystals than with the reference polycrystalline phosphor's 80-micron value. Initial images of 33-micron diameter carbon fibers have also been obtained with small crystals installed. Tests with a full-scale 88-mm diameter single crystal (patent-pending configuration) are being planned.
*A. Appel, M.A. Anastasio, and E.M. Brey, Tissue Eng. Part B Rev 17 (5), 321 (2011).
**A.H. Lumpkin, et al., Phys. Rev. ST-AB 14 (6), 060704 (2011).
 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA27  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA28 Feasibility of OTR Imaging for Laser-Driven Plasma Accelerator Electron-Beam Diagnostics 345
 
  • A.H. Lumpkin
    Fermilab, Batavia, Illinois, USA
  • M. Downer
    The University of Texas at Austin, Austin, Texas, USA
  • D.W. Rule
    Private Address, Silver Spring, USA
  
  Funding: * Work at Fermilab partly supported by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. DoE. ** Work at the Univ. of Texas supported by DoE grant DE-SC0011617.
Recent measurements of betatron x-ray emission from quasi-monoenergetic electrons accelerating to 500 MeV within a laser plasma accelerator (LPA) enabled estimates of normalized transverse emittance well below 1 mm-mrad and divergences of order 1/gamma [1]. Such unprecedented LPA beam parameters can, in principle, be addressed by utilizing the properties of linearly polarized optical transition radiation (OTR) that provide additional beam parameter sensitivity. We propose a set of complementary measurements of beam size and divergence with near-field and far-field OTR imaging, respectively, on LPA electron beams ranging in energy from 100 MeV [2] to 2 GeV [3]. The feasibility is supported by analytical modeling for beam size sensitivity and divergence sensitivity. In the latter case, the calculations indicate that the parallel polarization component of the far-field OTR pattern is sensitive to divergences from 0.1 to 0.4 mrad (σ) at 2 GeV, and it is similarly sensitive to divergences from 1 to 5 mrad (σ) at 100 MeV. We anticipate the signal levels from charges of 100 pC will require a 16-bit cooled CCD camera. Other practical challenges in the LPA will also be discussed.
1.G. R. Plateau et al., Phys. Rev. Lett. 109, 064802 (2012).
2.Hai-EnTsai, Chih-Hao Pai, and M.C. Downer, AIP Proc. 1507, 330 (2012)
3.Xiaoming Wang et al., Nature Communications 4,1988(2013).
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA28  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA29 Beam Position Monitoring System for the PIP-II Injector Test Accelerator 349
 
  • N. Patel, C.I. Briegel, J.S. Diamond, N. Eddy, B.J. Fellenz, J. Fitzgerald, V.E. Scarpine
    Fermilab, Batavia, Illinois, USA
  
  Funding: This work was supported by the U.S. Department of Energy under contract No. DE-AC02-07CH11359.
The Proton Improvement Plan II (PIP-II) injector test accelerator is an integrated systems test for the front-end of a proposed continuous-wave (CW) compatible, pulsed H− superconducting RF linac. This linac is part of Fermilab's PIP-II upgrade. This injector test accelerator will help minimize the technical risk elements for PIP-II and validate the concept of the front-end. Major goals of the injector accelerator are to test a CW RFQ and H− source, a bunch-by-bunch Medium-Energy Beam Transport (MEBT) beam chopper and stable beam acceleration through low-energy superconducting cavities. Operation and characterization of this injector places stringent demands on the types and performance of the accelerator beam diagnostics. A beam position monitor (BPM) system has been developed for this application and early commissioning measurements have been taken of beam transport through the beamline. 		 
poster icon Poster TUPOA29 [0.469 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA29  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA30 Fermilab Switchyard Resonant Beam Position Monitor Electronics Upgrade Results 352
 
  • T.B. Petersen, J.S. Diamond, N. Liu, P.S. Prieto, D. Slimmer, A.C. Watts
    Fermilab, Batavia, Illinois, USA
  
  The readout electronics for the resonant beam position monitors (BPMs) in the Fermilab Switchyard (SY) have been upgraded, utilizing a low noise amplifier transition board and Fermilab designed digitizer boards. The stripline BPMs are estimated to have an average signal output of between -110 dBm and -80 dBm, with an esti-mated peak output of -70 dBm. The external resonant circuit is tuned to the SY machine frequency of 53.10348 MHz. Both the digitizer and transition boards have vari-able gain in order to accommodate the large dynamic range and irregularity of the resonant extraction spill. These BPMs will aid in auto-tuning of the SY beamline as well as enabling operators to monitor beam position through the spill.  
poster icon Poster TUPOA30 [0.833 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA30  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA31 Fermilab Cryomodule Test Stand RF Interlock System 355
 
  • T.B. Petersen, J.S. Diamond, D. McDowell, D.J. Nicklaus, P.S. Prieto, A. Semenov
    Fermilab, Batavia, Illinois, USA
  
  An interlock system has been designed for the Fermilab Cryomodule Test Stand (CMTS), a test bed for the cryomodules to be used in the upcoming Linac Coherent Light Source 2 (LCLS-II) project at SLAC. The interlock system features 8 independent subsystems, consisting of a superconducting RF cavity, a coupler, and solid state amplifier (SSA). Each system monitors several devices to detect fault conditions such as arcing in the waveguides or quenching of the SRF system. Additionally each system can detect fault conditions by monitoring the RF power seen at the cavity coupler through a directional coupler. In the event of a fault condition, each system is capable of removing RF signal to the amplifier (via a fast RF switch) as well as turning off SSA. Additionally, each input signal is available for remote viewing and recording via a Fermilab designed digitizer board.  
poster icon Poster TUPOA31 [0.762 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA31  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA36 Computed Tomography of Transverse Phase Space 358
 
  • A.C. Watts, C. Johnstone, J.A. Johnstone
    Fermilab, Batavia, Illinois, USA
  
  Funding: Work supported by Fermi Reserach Alliance, LLC under Contract no. DE-AC02-07CH11359 with the United States Department of Energy.
Two computed tomography techniques are explored to reconstruct beam transverse phase space using both simulated beam and multi-wire profile data in the Fermilab Muon Test Area ("MTA") beamline. Both Filtered Back-Projection ("FBP") and Simultaneous Algebraic Reconstruction Technique ("SART") algorithms are considered and compared. Errors and artifacts are compared as a function of each algorithm's free parameters, and it is shown through simulation and MTA beamline profiles that SART is advantageous for reconstructions with limited profile data.
awatts@fnal.gov, cjj@fnal.gov, jjohnstone@fnal.gov 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA36  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA38 Real-Time Magnetic Electron Energy Spectrometer for Use With Medical Linear Acceletors 361
SUPO27   use link to see paper's listing under its alternate paper code  
 
  • P.E. Maggi, H.R. Hogstrom, K.L. Matthews II
    LSU, Baton Rouge, USA
  • R.L. Carver
    Mary Bird Perkins Cancer Center, Our Lady of the Lake, Baton Rouge, USA
  
  Accelerator characterization and quality assurance is an integral part of electron linear accelerator (linac) use in a medical setting. The current clinical method for radia-tion metrology of electron beams (dose on central axis versus depth in water) only provides a surrogate for the underlying performance of the accelerator and does not provide direct information about the electron energy spectrum. We have developed an easy to use real-time magnetic electron energy spectrometer for characterizing the electron beams of medical linacs. Our spectrometer uses a 0.57 T permanent magnet block as the dispersive element and scintillating fibers coupled to a CCD camera as the position sensitive detector. The goal is to have a device capable of 0.12 MeV energy resolution (which corresponds to a range shift of 0.5 mm) with a minimum readout rate of 1 Hz, over an energy range of 5 to 25 MeV. This work describes the real-time spectrometer system, the detector response model, and the spectrum unfolding method. Measured energy spectra from multi-ple electron beams from an Elekta Infinity Linac are presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA38  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA40 Low Noise Digitizer Design for LCLS-II LLRF 364
 
  • G. Huang, L.R. Doolittle, Y.L. Xu, J. Yang
    LBNL, Berkeley, California, USA
  • Y.L. Xu, J. Yang
    TUB, Beijing, People's Republic of China
  
  Modern accelerators use a digital low level RF controller to stabilize the fields in accelerator cavities. The noise in the receiver chain and analog to digital conversion (ADC) for the cavity probe signal is critically important. Within the closed-loop bandwidth, it will eventually become part of the field noise seen by the beam in the accelerator. Above the open-loop cavity bandwidth, feedback processes transfer that noise to the high power drive amplifiers. The LCLS-II project is expected to use an undulator to provide soft X-rays based on a stable electron beam accelerated by a superconducting linac. Project success depends on a low noise, low crosstalk analog to digital conversion. We developed a digitizer board with 8 ADC channels and 2 DAC channels. The broadband phase noise of this board is measured at <-151\thinspace dBc/Hz, and the adjacent channel crosstalk is measured at <-80\thinspace dB. In this paper we describe the digitizer board design, performance test procedures, and bench-test results.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA40  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA41 FPGA Control of Coherent Pulse Stacking 367
SUPO52   use link to see paper's listing under its alternate paper code  
 
  • Y.L. Xu, J.M. Byrd, L.R. Doolittle, Q. Du, G. Huang, W. Leemans, R.B. Wilcox, Y. Yang
    LBNL, Berkeley, California, USA
  • J. Dawson
    LLNL, Livermore, California, USA
  • A. Galvanauskas, J.M. Ruppe
    University of Michigan, Ann Arbor, Michigan, USA
  
  Coherent pulse stacking (CPS) is a new time-domain coherent addition technique that stacks several optical pulses into a single output pulse, enabling high pulse energy from fiber lasers. Due to advantages of precise timing and fast processing, we use an FPGA to process digital signals and do feedback control so as to realize stacking-cavity stabilization. We develop a hardware and firmware design platform to support the coherent pulse stacking application. A firmware bias control module stabilizes the amplitude modulator at the minimum of its transfer function. A cavity control module ensures that each optical cavity is kept at a certain individually-prescribed and stable round-trip phase with 2.5 deg rms phase error.  
poster icon Poster TUPOA41 [5.546 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA41  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA42 Multicavity Coherent Pulse Stacking Using Herriott Cells 370
 
  • Y. Yang, J.M. Byrd, L.R. Doolittle, G. Huang, W. Leemans, Q. Qiang, R.B. Wilcox
    LBNL, Berkeley, California, USA
  • J. Dawson
    LLNL, Livermore, California, USA
  • A. Galvanauskas, J.M. Ruppe
    University of Michigan, Ann Arbor, Michigan, USA
  • Y.L. Xu
    TUB, Beijing, People's Republic of China
  
  Coherent Pulse Stacking provides a promising way to generate a single high-intensity laser pulse by stacking a sequence of phase and amplitude modulated laser pulses using multiple optical cavities. Optical misalignment and phase stability are two critical issues that need to be addressed. Herriott cells are implemented for their relaxed alignment tolerance and a phase stabilization method based on cavity output pattern matching has been developed. A single pulse with intensity enhancement factor over 7.4 has been generated by stacking 13 modulated pules through a four-cavity stacking system. This can be a possible path for generating TW KHz laser pulses for a future laser-driven plasma accelerator.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA42  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA44 Future Prospects of RF Hadron Beam Profile Monitors for Intense Neutrino Beam 373
SUPO24   use link to see paper's listing under its alternate paper code  
 
  • Q. Liu
    Case Western Reserve University, Cleveland, USA
  • M. Backfish, A. Moretti, V. Papadimitriou, A.V. Tollestrup, K. Yonehara, R.M. Zwaska
    Fermilab, Batavia, Illinois, USA
  • M.A. Cummings, R.P. Johnson, G.M. Kazakevich
    Muons, Inc, Illinois, USA
  • B.T. Freemire
    IIT, Chicago, Illinois, USA
  
  Funding: Work supported by Fermilab Research Alliance, LLC under Contract No. DE-AC02-07CH11359 and DOE STTR Grant, No. DE-SC0013795.
A novel beam monitor based on a gas-filled RF resonator is proposed to measure the precise profile of secondary particles downstream of a target in the LBNF beam line at high intensity. The RF monitor is so simple that it promises to be radiation robust in extremely high-radiation environment. When a charged beam passes through a gas-filled microwave RF cavity, it produces electron-ion pairs in the RF cavity. The induced plasma changes the gas permittivity in proportion to the beam intensity. The permittivity shift can be measured by the modulated RF frequency and quality factor. The beam profile can thus be reconstructed from the signals from individual RF cavity pixels built into the beam profile monitor. A demonstration test is underway, and the current results has shown technical feasibility. The next phase consists of two stages, (1) to build and test a new multi-cell 2.45 GHz RF cavity that can be used for the NuMI beamline, and (2) to build and test a new multi-cell 9.3 GHz RF cavity that can be put in service in a future beamline at the LBNF for spatial resolution. These two resonant frequencies are chosen since they are the standard frequencies for magnetron RF source. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA44  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA46 Development of a Python-Based Emittance Calculator at Fermilab Science & Technology (FAST) Facility 376
SUPO61   use link to see paper's listing under its alternate paper code  
 
  • A.T. Green
    Northern Illinois Univerity, DeKalb, Illinois, USA
  • Y.-M. Shin
    Fermilab, Batavia, Illinois, USA
  • Y.-M. Shin
    Northern Illinois University, DeKalb, Illinois, USA
  
  Beam emittance is an important characteristic which helps to describe a charged particle beam. In linear accelerators (linac), it is critical to characterize the beam phase space parameters and, in particular, to precisely measure transverse beam emittance. The quadrupole scan (quad-scan) is a well established technique used to characterize transverse beam parameters in four-dimensional phase space. Quad-scans are very time consuming and off-line analysis is needed to extrapolate the beam phase space parameters. We have developed a computational algorithm with Python scripts to automatically estimate beam parameters, in particular beam emittance, using the quadrupole scan technique in the electron linac of Fermilab Accelerator Science and Technology (FAST) facility. These Python scripts have decreased the time it takes to perform a single quad scan from a few hours to a few minutes. From the experimental data, the emittance calculator quickly delivers various results including: transverse emittance, Courant-Snyder parameters, and Beam Size (squared) vs Quadrupole field strength plots, among others.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA46  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA47 Development of Short Undulators for Electron-Beam-Radiation Interaction Studies 380
 
  • P. Piot
    Fermilab, Batavia, Illinois, USA
  • M.B. Andorfpresenter, G. Fagerberg, M. Figora
    Northern Illinois University, DeKalb, Illinois, USA
  
  Funding: Work supported by the US DOE contract DE-SC0013761 with Northern Illinois University
Interaction of an electron beam with external field or its own radiation has widespread applications ranging from coherent radiation generation, phase space cooling or formation of time-structured beam. An efficient coupling mechanism between an electron beam and radiation field relies on the use of a magnetic undulator. In this contribution we detail the construction and magnetic measurements of short (11 period) undulators with 7-cm period built using parts of the ALADDIN U3 undulator*. Possible use of these undulators at two accelerator test facilities to support experiment relevant to cooling techniques and radiation souces are discussed.
* F. C. Younger, W. Jorge Pearce, B. Ng, Nucl. Instrum. Meth Phys. Res. A 347, pp. 96-101 (1994). 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA47  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA48 A High-Level Python Interface to the Fermilab ACNET Control System 383
 
  • P. Piot
    Fermilab, Batavia, Illinois, USA
  • A. Halavanaupresenter
    Northern Illinois University, DeKalb, Illinois, USA
  
  This paper discusses the implementation of a PYTHON-based high-level interface to the Fermilab ACNET control system. We will especially present examples of applications which include the interfacing of an ELEGANT beam-dynamics model to assist lattice matching and an automated emittance measurement via the quadrupole-scan method.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA48  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA49 A General Model of Vacuum Arcs in Linacs 387
 
  • J. Norem
    Nano Synergy, Inc., Downers Grove, Illinois, USA
  • Z. Insepov
    Purdue University, West Lafayette, Indiana, USA
  
  We are developing a general model of breakdown and gradient limits that applies to accelerators, along with other high field applications such as power grids and laser ablation. Our recent efforts have considered failure modes of integrated circuits, sheath properties of dense, non-Debye plasmas and applications of capillary wave theory to rf breakdown in linacs. In contrast to much of the rf breakdown effort that considers one physical mechanism or on e experimental geometry, we are finding that there is an enormous volume of relevant material in the literature that helps to constrain our model and suggest experimental tests.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA49  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA51 First Steps Toward Incorporating Image Based Diagnostics into Particle Accelerator Control Systems Using Convolutional Neural Networks 390
SUPO10   use link to see paper's listing under its alternate paper code  
 
  • A.L. Edelen, S. Biedron, S.V. Milton
    CSU, Fort Collins, Colorado, USA
  • J.P. Edelen
    Fermilab, Batavia, Illinois, USA
  
  At present, a variety of image-based diagnostics are used in particle accelerator systems. Often times, these are viewed by a human operator who then makes appropriate adjustments to the machine. Given recent advances in using convolutional neural networks (CNNs) for image processing, it should be possible to use image diagnostics directly in control routines (NN-based or otherwise). This is especially appealing for non-intercepting diagnostics that could run continuously during beam operation. Here, we show results of a first step toward implementing such a controller: our trained CNN can predict multiple simulated downstream beam parameters at the Fermilab Accelerator Science and Technology (FAST) facility's low energy beamline using simulated virtual cathode laser images, gun phases, and solenoid strengths.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA51  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA52 Updates to the Low-Level RF Architecture for Fermilab 394
 
  • J. Einstein, B.E. Chase, E. Cullerton, P. Varghese
    Fermilab, Batavia, Illinois, USA
  • S. Biedron, S.V. Milton
    CSU, Fort Collins, Colorado, USA
  • D. Sharma
    RRCAT, Indore (M.P.), India
  
  Fermilab has teamed with Colorado State University on several projects in LLRF controls and architecture. These projects include new LLRF hardware, updated controls techniques, and new system architectures. Here we present a summary of our work to date.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA52  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA54 Examination of Out-of-Field Dose and Penumbral Width of Flattening Filter Free Beams in Medical Linear Accelerators 396
 
  • L.C. Bennett, O.N. Vassiliev
    M.D.A.C.C., Houston, Texas, USA
  
  Medical linear accelerators (LINACS) have traditionally used a flattening filter to ensure that the photon spectrum entering the patient was homogeneous within a given field size. Recently, leading manufacturers of medical accelerators have begun including an option for Flattening Filter Free (FFF) beams on their accelerators. These beams are characterized by a softer spectrum (lower average energy), peaked profiles, and less side scatter. Previous work with Monte Carlo models has shown that the elimination of the flattening filter from the beam path has the potential to greatly reduce scatter in regions immediately adjacent to the primary field (Kry 2010); however, systematic in-depth investigation of these effects has yet to be done using actual measurements from a linac equipped with FFF beams. We have examined and compared measurements of different energy pairings of FFF and FF beams from the Varian TrueBeam accelerators and found reductions of peripheral dose at upwards of 30% for the FFF beams and nearly 5% reduction in penumbral width at nearly all depths and field sizes; reductions were greatest for shallow depths and small field size.
Kry et al. Out-of-field photon dose following removal of the flattening filter from a medical accelerator. Physics in Medicine and Biology. vol. 55, no. 8, 2010. pp 2155-2166. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA54  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA57 Using High­ Precision Beam Position Monitors at the Cornell Electron Storage Ring (CESR) to Measure the One­ Way Speed of Light Anisotropy 399
 
  • W.F. Bergan, M.J. Forster, N.T. Rider, D. L. Rubin, D. Sagan
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • B.A. Schmookler
    MIT, Cambridge, Massachusetts, USA
  • B. Wojtsekhowski
    CMU, Pittsburgh, Pennsylvania, USA
  
  Funding: NSF PHY-1416318 NSF DGE-1144153
The Cornell Electron Storage Ring (CESR) has been equipped with a number of high-precision beam position monitors which are capable of measuring the orbit of a circulating beam with a precision of a few microns. This technology will enable a precision measurement of deviations in the one-way speed of light. An anisotropic speed of light will alter the beam momentum as it travels around the ring, resulting in a change of orbit over the course of a sidereal day. Using counter-circulating electron and positron beams, we will be able to suppress many of the systematics such as those relating to variations in RF voltage or magnet strength. We show here initial feasibility studies to measure the stability of our beam position monitors and the various systematic effects which may hide our signal and discuss ways in which we can minimize their impact. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA57  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA58 Minimization of Emittance at the Cornell Electron Storage Ring With Sloppy Models 402
SUPO03   use link to see paper's listing under its alternate paper code  
 
  • W.F. Bergan, A.C. Bartnik, I.V. Bazarov, H. He, D. L. Rubin
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • J.P. Sethna
    Cornell University, Ithaca, New York, USA
  
  Funding: DOE DE-SC0013571 NSF DGE-1144153
Our current method to minimize the vertical emittance of the beam at the Cornell Electron Storage Ring (CESR) involves measurement and correction of the dispersion, coupling, and orbit of the beam and lets us reach emittances of 10 pm, but is limited by finite dispersion measurement resolution.* For further improvement in the vertical emittance, we propose using a method based on the theory of sloppy models.** The storage ring lattice permits us to identify the dependence of the dispersion and emittance on our corrector magnets, and taking the singular value decomposition of the dispersion/corrector Jacobian gives us the combinations of these magnets which will be effective knobs for emittance tuning, ordered by singular value. These knobs will permit us to empirically tune the emittance based on direct measurements of the vertical beam size. Simulations show that when starting from a lattice with realistic alignment errors which has been corrected by our existing method to have an emittance of a few pm, this new method will enable us to reduce the emittance to nearly the quantum limit, assuming that vertical dispersion is the primary source of our residual emittance.
* J. Shanks, D.L. Rubin, and D. Sagan, Phys. Rev. ST Accel. Beams 17, 044003 (2014).
** K.S. Brown and J.P. Sethna, Phys. Rev. E 68, 021904 (2003). 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA58  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA59 Successful Laboratory-Industrial Partnerships: the Cornell-Friatec Segmented Insulator for High Voltage DC Photocathode Guns 405
 
  • K.W. Smolenski, B.M. Dunham
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • D.L. Barthpresenter, M. Muehlbauer, S. Wacker
    FRIATEC AG, Mannheim, Germany
  • J.M. Maxson
    UCLA, Los Angeles, California, USA
  
  High voltage DC photocathode guns currently offer the most reliable path to electron beams with high current and brightness. The performance of a gun is directly dependent on its vacuum and high voltage capabilities, determined in large part by the ceramic insulators. The insulator must meet XHV standards, bear the load of pressurized SF6 on its exterior, support the massive electrode structures as well as holding off DC voltages up to 750kV. Construction of UHV and high voltage capable insulators require high purity ceramics and metal components proven to minimize thermal stress between the brazed ceramic rings and metal guard rings. The use of replaceable guard rings is a critical way of controlling manufacturing costs while extending the life cycle of the insulator. Successful fabrication requires proven manufacturing methods in flatness, parallelism, and maintaining alignment of many parts during the brazing process. Taking a scalable, modular approach, the insulator design can be applied to a variety of gun voltages and can be used by other projects. The Cornell-Friatec insulator was designed collaboratively and has now been produced in quantity for Cornell and elsewhere.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA59  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA61 Integrated Control System for an X-Band-Based Laser-Compton X-Ray Source 408
 
  • D.J. Gibson, G.G. Anderson, C.P.J. Barty, R.A. Marsh
    LLNL, Livermore, California, USA
  
  Funding: This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
LLNL's compact, tunable, laser-Compton x-ray source has been built around an advanced X-band photogun and accelerator sections and two independent laser systems. In support of this source, the control system has evolved from a minimal, isolated control points to an integrated architecture that continues to grow to simplify operation of the system and to meet new needs of this research capability. In addition to a PLC-based machine protection component, a custom, LabView-based suite of control software monitors systems including low level and high power RF, vacuum, magnets, and beam imaging cameras. This system includes a comprehensive operator interface, automated arc detection and rf processing to optimize rf conditioning of the high-gradient structures, and automated quad-scan-based emittance measurements to explore the beam tuning parameter space. The latest upgrade to the system includes a switch from real-time OS to FPGA-based low-level RF generation and arc detection. This offloads processing effort from the main processor allowing for arbitrary expansion of the monitored points. It also allows the possibility of responding to arcs before the pulse is complete. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA61  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA63 Preliminary Study of Advanced LLRF Controls at LANSCE for Beam Loading Compensation in the MaRIE X-FEL 411
 
  • A. Scheinker, S.A. Baily, J.T. Bradley III, L.J. Castellano, J.O. Hill, D.J. Knapp, S. Kwon, J.T.M. Lyles, M.S. Prokoppresenter, D. Rees, P.A. Torrez
    LANL, Los Alamos, New Mexico, USA
  
  The analog low level RF (LLRF) control system of the Los Alamos Neutron Science Center is being upgraded to a Field Programmable Gate Array (FPGA)-based digital system (DLLRF). In this paper we give an overview of the FPGA design and the overall DLLRF system. We also present preliminary performance measurements including results utilizing model-independent iterative feedforward for beam-loading transient minimization, which is being studied for utilization in the future MaRIE X-FEL, which will face difficult beam loading conditions.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA63  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA64 Effects of Low Frequency Buncher Field (LFB) Variation on an H− Beam Phase-Energy 414
 
  • P.K. Roy, Y.K. Batygin
    LANL, Los Alamos, New Mexico, USA
  
  Funding: This work supported by the United States Department of Energy under contract DE-AC52-06NA25396
Beam bunching optimization at low energy (750keV) before injecting into a DTL (100MeV) is essential for beam transport, emittance reduction, and focusing on to a target. The LANSCE simultaneously utilizes H+ and H− beam (with a timing variation) for many important national security sciences. In addition to quadrupole, several bunchers are utilized in the transport. A technique with pre-bunching at lower frequency and main bunching at higher frequency is utilized for beam injection into the linac. The buncher parameters (voltage and frequency) are well established for operations. However, there is the possibility that the parameters vary with time due to electrical malfunction or adverse tuning during a beam development activity. Some effort is needed to correct the parameters as a non-optimized pre-bunching setup can alter the beam phase space and the nominal beam intensity at a desired location. Here, we examine emittance and phase space distribution variation for H− beam due to variation of the low frequency (16 MHz) buncher voltage, which typically operates at 25 kV peak. Beam phase dynamics with buncher voltage variation is also examined using the beam transport code Parmila.
LA-UR-16-23822
LANSCE: Los Alamos Neutron Science Center
DTL: Drift Tube Linac 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA64  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA67 Helium Pressure Vessel Jacketing of the Fermilab SSR1 Single Spoke SC Cavities 418
 
  • E.C. Bonnema, E.K. Cunningham
    Meyer Tool & MFG, Oak Lawn, Illinois, USA
  
  Meyer Tool recently completed the welding of the liquid helium pressure vessel jackets around ten (10) superconducting single spoke niobium cavities for Fermilab. The SSR1 cavities are intended for use in the PIP-II Injector Experiment Cryomodule. Meyer Tool's scope of supply included review of the Fermilab Pressure Rating Analysis Document and the development of fabrication details and a fabrication sequence to meet that document's requirements, while minimizing the effects of jacketing cavity frequency, and the actual jacketing of the cavities. This paper will focus on the development of the fabrication details and sequence and how the details and sequence evolved over the course of welding and final machining of the ten (10) jackets. As the frequency of these cavities is critical the fabrication sequence accommodated numerous in process frequency checks, a frequency tuning step prior to the final weld, the use of thermal cameras to monitor weld heat input into the cavity, and post welding final machining of critical features. Lessons learned from this fabrication will be discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA67  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA68 Design, Simulations and Experimental Demonstration of an Intra-Pulse Ramped-Energy Travelling Wave Linac for Cargo Inspection 421
 
  • S.V. Kutsaev, R.B. Agustsson, A. Arodzero, R.D.B. Berry, S. Boucher, Y.C. Chen, J.J. Hartzell, B.T. Jacobson, A. Laurich, A.Y. Murokh, E.A. Savin, A.Yu. Smirnov, A. Verma
    RadiaBeam, Santa Monica, California, USA
  
  Funding: This work has been supported by the US Department of Homeland Security, Domestic Nuclear Detection Office, under competitively awarded contract HSHQDC-13-C-B0019.
Novel radiographic imaging techniques [1] based on adaptive, intra-pulse ramped-energy short X-ray packets of pulses, a new type of fast X-ray detectors, and advanced image processing are currently some of the most promising methods for real-time cargo inspection systems. RadiaBeam Technologies is currently building the high-speed Adaptive Railroad Cargo Inspection System (ARCIS), which will enable better than 5 mm line pair resolution, penetration greater than 450 mm of steel equivalent, material discrimination over the range of 6 mm to 250 mm, 100% image sampling rate at speed 45 km/h, and minimal average dose. One of the core elements of ARCIS is a new S-band travelling wave linac with a wide range of energy control that allows energy ramping from 2 to 9 MeV within a single 16 μs RF pulse using the beam loading effect. In this paper, we will discuss the linac design approach and its principal components, as well as engineering and manufacturing aspects. The results of the experimental demonstration of intra-pulse energy ramping will be presented.
[1] A. Arodzero, S. Boucher, A. Murokh, S. Vinogradov, S.V. Kutsaev. System and Method for Adaptive X-ray Cargo Inspection. US Patent Application 2015/1472051. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA68  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA71 Beam Stability During Top Off Operation at NSLS-II Storage Ring 425
 
  • W.X. Cheng, B. Bacha, Y. Li, O. Singh, Y. Tian
    BNL, Upton, Long Island, New York, USA
  
  NSLS-II storage ring started top off operation since Oct 2015. User operation current has been gradually increased to 250mA. Observations of beam stabilities during top-off operations will be presented. Total beam current was typically maintained within ±0.5% and bunch to bunch current variation was less than 20%. Injection transition during top-off was measured bunch by bunch digitizer, and BPM to analyze the orbit motion at various bandwidths (turn by turn, 10kHz and 10Hz rate). Coupled bunch unstable motions were monitored. As the vacuum pressure improves, fast-ion instability is not as severe compared to early stage of commissioning/operation, but still observed as the dominant instability. Resistive wall instability is noticed as more in-vacuum-undulator (IVU) gaps closed. xBPM measured photon stability and electron beam stability at top off injection have been evaluated. Short term and long term orbit stabilities will be reported.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA71  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA73 Commissioning and First Results From a Channeling-Radiation Experiment at FAST 428
SUPO56   use link to see paper's listing under its alternate paper code  
 
  • J. Hyun
    Sokendai, Ibaraki, Japan
  • D.R. Broemmelsiek, D.R. Edstrom, A.L. Romanov, J. Ruan, T. Sen, V.D. Shiltsev
    Fermilab, Batavia, Illinois, USA
  • A. Halavanaupresenter, D. Mihalcea
    Northern Illinois University, DeKalb, Illinois, USA
  • P. Kobak
    BYU-I, Rexburg, USA
  • W.D. Rush
    KU, Lawrence, Kansas, USA
  
  X-rays have widespread applications in science. Developing compact and high-quality X-ray sources, easy to disseminate, has been an on going challenge. Our group has explored the possible use of channeling radiation driven by a 50 MeV low-emittance electron beam to produce narrowband hard X-rays (photon energy from 40 keV to 140 keV). In this contribution we present the simulated X-ray spectrum including the background bremsstrahlung contribution, and optimization of the relevant electron-beam parameters required to maximize the X-ray brilliance. The results of experiments carried out at Fermilab's FAST facility – which include a 50 MeV superconducting linac and a high-brightness photoinjector – are also discussed. The average brilliance in our experiment is expected to be about one order of magnitude higher than that in previous experiments.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA73  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA74 The Design and Construction of a Resonance Control System for the IOTA RF Cavity 432
SUPO57   use link to see paper's listing under its alternate paper code  
 
  • G.M. Bruhaug
    ISU, Pocatello, Idaho, USA
  • K. Carlson
    Fermilab, Batavia, Illinois, USA
  
  The IOTA ring will be an advanced storage ring used for non-linear beam dynamics experiments to assist in the construction of future accelerators. This ring is being built in conjunction with the FAST electron LINAC and the HINS RFQ proton source, at Fermilab, for injection into the ring. These accelerators will generate +150 MeV electron beams and 2.5 MeV proton beams respectively. As the beams are injected into the IOTA storage ring their longitudinal profile will begin to smear out and become more uniform. This will prevent detection of beam position with a Beam Position Monitoring system (BPM). To combat this a ferrite loaded bunching cavity is being constructed. This paper details the design and construction of an automatic resonance control system for this bunching cavity.  
poster icon Poster TUPOA74 [2.604 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA74  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA75
 Operational Experience with Fast Fiber-Optic Beam Loss Monitors for the Advanced Photon Source Storage Ring Superconducting Undulators  
MOA3CO04   use link to access more material from this paper's primary paper code  
 
  • J.C. Dooling, K.C. Harkay, V. Sajaev, H. Shang
    ANL, Argonne, Illinois, USA
  
  Funding: Work supported by the U.S. Department of Energy, Office of Science, under contract number DE-AC02-06CH11357.
Fast fiber-optic (FFO) beam loss monitors (BLMs) installed with the first two superconducting undulators (SCUs) in the Advanced Photon Source storage ring have proven to be a useful diagnostic for measuring deposited charge (energy) during rapid beam loss events. The first set of FFOBLMs were installed outside the cryostat of the short SCU, a 0.33-m long device, above and below the beam centerline. The second set are mounted with the first 1.1-m-long SCU within the cryostat, on the outboard and inboard sides of the vacuum chamber. The next 1.1-m-long SCU is scheduled to replace the short SCU later in 2016 and will be fitted with FFOBLMs in a manner similar to original 1.1-m device. The FFOBLMs were employed to set timing and voltage for the abort kicker (AK) system. The AK helps to prevent quenching of the SCUs during beam dumps* by directing the beam away from the SC magnet windings. The AK is triggered by the Machine Protection System (MPS). In cases when the AK fails to prevent quenching, the FFOBLMs show that losses often begin before detection by the MPS.
K. Harkay et al., these proceedings 		 
slides icon Slides TUPOA75 [1.188 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOA3CO04  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)