CASE/C-AD seminars for graduate students and postdocs
The main goal of the CASE seminars is to provide a venue where grad students and postdocs can get together, learn about each others' research and open their scientific horizons in general. The seminars will be a mix of student’s and postdoc’s presentations of their recent results, dry runs of conference presentations, reviews of journal articles, visits to BNL accelerators and testing areas and occasional invited presentations by senior scientists from BNL and SBU.
The seminars are typically held every other Thursday, from 4:30 to 5:30 pm in the RHIC Main Control Room meeting area (bldg. 911B, 2nd floor) at BNL.
- June 06, 2017: Beam diagnostics in 112 MHz SRF e-gun with CsK2Sb photo-cathode: emittance measurement and phase space reconstruction by Kentaro Mihara (BNL/SBU).
- Abstract: The commissioning of the Coherent electron Cooling (CeC) proof of principle experiment is under way at the Relativistic Heavy Ion Collider (RHIC). A 112 MHz Superconducting Radio Frequency (SRF) photo-emission gun is used to generate the electron beam for this experiment. In this presentation I report selected results of experimental emittance measurements and compare them with our simulations. After that, phase space reconstruction by tomography method is discussed.
- May 25, 2017: RHIC stochastic cooling by Mike Blaskiewicz (BNL).
- May 4, 2017: A new testing platform and client-server game theory applied in the RHIC control system by Yuan Gao (BNL/SBU).
- Abstract: The control systems of the Collider-Accelerator Department (C-AD) at Brookhaven National Laboratory (BNL) is a complex system consisting of approximately 1.5 million control points. Instances of C-AD control systems are applied in the Linear Accelerator (Linac), Electron Beam Ion Source (EBIS), Tandem Van de Graff pre-accelerators, the Booster accelerator, Alternating Gradient Synchrotron (AGS), and the Relativistic Heavy Ion Collider (RHIC). Thus, its performance has a crucial impact over the whole accelerator suite. In this presentation, we discuss several projects related to the RHIC control system, which is a typical implementation of the C-AD control system, aiming to improve its performance.
- April 13, 2017: Heat transfer study for the BNL double ridge higher order mode waveguide by Dhananjay Ravikumar (BNL/SBU).
- Abstract: Brookhaven National Laboratory (BNL) has proposed to build an Electron Ion Collider (EIC) as an upgrade to the existing Relativistic Heavy Ion Collider (RHIC). A part of the new design is to use Superconducting Radio Frequency (SRF) cavities for acceleration, which sit in a bath of superfluid Helium at a temperature of 2 K. SRF cavities designed for the BNL EIC create a standing Electromagnetic wave, oscillating at a fundamental frequency of 647 MHz. Interaction of the charged particle beam with the EM field in the cavity creates Higher Order Modes (HOM) of oscillation which have adverse effects on the beam if it is allowed to propagate down the beam tube. HOM waveguides are thus designed to remove this excess energy which is then damped at room temperature. As a result, these waveguides provide a direct thermal link between room temperature and the superconducting cavities adding a static thermal load. The EM wave propagating through the warmer sections of the waveguide creates and additional dynamic thermal load. This study aims to estimate these thermal loads, map temperature distributions on the waveguide and come up with an efficient design to manage heat flow such that the load on the 2 K cryogenic system is as low as possible.
- March 7, 2017: Multipacting simulations for the CeC PoP superconducting photo-electron gun by Irina Petrushina (BNL/SBU).
- Abstract: Multipacting is a complex phenomenon in which a large number of electrons build up within the cavity volume leading to the undesirable RF power absorption. The 112 MHz Superconducting Photo-electron Gun used for the Coherent electron Cooling Proof-of-Principle (CeC PoP) experiment encountered several multipacting zones during the Run'16. In order to understand performance limitations for the next run, a series of numerical and analytical calculations was performed. Methods for multipacting calculations and the results obtained for the SRF Gun will be presented and discussed.
- February 2, 2017: Beam Break-Up (BBU) instability simulations for Cornell CBETA by William Lou (Cornell University).
- Abstract: Beam breakup instability occurs in recirculating accelerators when beam bunches interact with higher order modes (HOMs) in accelerating cavities. BBU is an important limiting factor to the maximum achievable current in an ERL. Cornell and BNL are currently designing CBETA, a prototype accelerator for future eRHIC upgrade. To find out the threshold current of CBETA due to BBU instability, beam-tracking simulations were run using Bmad software. In this talk I will talk about basic BBU theory, how Bmad models BBU effects, and potential ways to increase the threshold current.
Season coordinator: Dr. Silvia Verdú-Andrés.
- September 28, 2016: The Relativistic Heavy Ion Collider RHIC (part II): polarized proton operation by Thomas Roser (BNL).
- July 7, 2016: The Relativistic Heavy Ion Collider RHIC (part I): heavy ion operation by Thomas Roser (BNL).
- May 10, 2016: C-AD Main Control Room tour by Kiel Hock (BNL).
- April 28, 2016: HOM studies and measurements for multi-bunch beams in SRF cavities by Yongfeng Gao (Peking University).
- March 15, 2016: Accelerator Driven Systems for nuclear waste transmutation by Malek Haj Tahar (Grenoble Institute of Technology-Phelma/BNL).
- Abstract: The problem of nuclear waste continues to raise lots of concerns of whether the nuclear power should continue when the issue of how to deal with its waste has not yet been resolved. After reviewing the history of the nuclear waste problem in the United States of America and other countries, the question of how to remedy this problem is tackled and several options discussed. The focus is on the Accelerator Driven System option, a hybrid technique combining a particle accelerator with a subcritical core. The scope includes technical considerations from the proton accelerator and up to the reactor core.
- Discussion facilitator: Irina Petrushina (SBU/BNL).
- March 1, 2016: Beam dynamics studies for Coherent Electron Cooling experiment by Yuan Wu (SBU/BNL).
- Abstract: Coherent electron Cooling (CeC) is a proposed advanced beam cooling method that has the potential of reducing the ion beam emittance in significantly shorter amount of time compared to existing cooling methods. The newly constructed linear electron accelerator (Linac) for the CeC experiment needs to generate electron beam with the required properties in order to maximize the CeC cooling capacity. In this thesis, the author studied the beam dynamics of the CeC linac and simulated the electron beam using beam dynamics tracking code. By utilizing optimization algorithms and beam manipulation techniques, the author has explored the performance of the current CeC Linac. The author ran an end-to-end simulation to model the entire beam line from the generation of electron beam from photocathode to the transport of electron beam to the CeC Free Electron Laser (FEL) section. The results have shown many aspects of the current CeC Linac and would be beneficial to future operation, research and development.
- Discussion facilitator: Jun Ma (SBU/BNL).
- February 23, 2016: informative meeting.
Season coordinator: Dr. Silvia Verdú-Andrés.
- April 22, 2014: Diamond detector -- material science, design and application by Mengjia Gaowei (SBU/BNL).
- April 8, 2014: Higher Order Mode Characterization and Damping in the BNL3 Linear Accelerator by Carlos Marques (SBU/BNL).
- March 25, 2014: Recent Progress in RHIC Accelerator Science and Applications by Qiong Wu (BNL).
Season coordinators: Prof. Sergey Belomestnykh and Dr. Qiong Wu.
Other seminars or academic events of interest
- September 8, 2016: Particle Accelerators and Accelerator Control Systems: An Engineering Introduction by Kevin Brown. Venue: Thursday, September 8, 2016 at 4:00pm in Light Engineering Building, Room 250 at Stony Brook University.
- September 7-8, 2016: Diversity & Inclusion workshop. Venue: September 7-8, 2016 at BNL.
- March 10, 2016: OSTI dedicated meeting to students and postdocs to present their tools and services. Venue: Thursday, March 10, 2016 in Bldg. 467 - Room 157 (seminar room in Biology building) at BNL.
- February 23, 2016: Proposal & Grant Writing Presentation for Students and Postdocs organized by BNL. Venue: Tuesday, February 23, 2016 in RSB 1 & 2 in Bldg. 400 at BNL.
Collection of papers and talks on Accelerator Physics & Technology and beyond:
- M. Blaskiewicz, Cooling of High-Energy Hadron Beams, Annu. Rev. Nucl. Part. Sci. 64, 299–317 (2014).
- H. S. Padamsee, Superconducting Radio-Frequency Cavities, Annu. Rev. Nucl. Part. Sci. 64, 175–96 (2014).
- R. M. May, Simple Mathematical Models with Very Complicated Dynamics, Nature 261, 459-467 (1976).
- R. R. Wilson, Radiological Use of Fast Protons, Radiology 47, 487-491 (1946).
N.B. Some links may only work inside the BNL network.
Please send your questions and suggestions to Silvia Verdú-Andrés