MPM-B - Accelerator Centennial Ballroom 300B 14:30 - 17:55
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| Chair(s): Robert May
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MPM-B.1
14:30 Removal of highly activated Isotope Production Facility window assembly from the window-collimator cask. MD Duran, LANL
; JV Vigil*, LANL
Abstract: LANSCE recently encountered a situation where beam was inadvertently sent to the Isotope Production Facility (MPF-984) which ultimately burned a hole in the beam window. As a result, a new beam window assembly along with a new collimator mechanism had to be assembled and installed in order to be prepared for 100-MeV production mode. The team was tasked with recovering the old beam assembly which included both the highly activated window and collimator assembly, from the blue shielded “cannon”, which included cutting the beam assembly into individual pieces in a containment enclosure and disposing of in shielding casks/55-gallon drum. The “cannon” was extremely essential and very much needed in order to remove the existing burned window and beam assembly from the IPF beam line.
Previous radiological surveys indicated levels of ~ (90 R/h @ 30cm) on the IPF window/collimator (with removable contamination potential) in the inside of the “cannon” which was stored in a different location (Building 3-M). Thus, a remote handling robot (brokk robot) attached to a band saw was utilized inside of the hood enclosure. Ultimately, the cutting of the beam pipe assembly in the containment enclosure resulted in minimal contamination and external radiological hazards were much lower than anticipated. Overall, the job was successful and the “cannon” was decontaminated and handed over to IPF.
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MPM-B.2
14:50 Utility and assessment of the code TALYS-1.96 in accelerator-based production of radioisotopes. G Akabani*, Asociación Mexicana de RadioProtección, AC
Abstract: TALYS is open-source software for the simulation of nuclear reactions. It has been used to simulate radioisotope production for many incident particles. It has been used as a benchmark for comparison purposes. Here we present a summary of Talys-19.6 and its capabilities and describe the production methods, and a comparison of yields, specific activities, and related impurities with experimental results for At-211 via Bi-209(α,2n)At-211, Cu-64 via Ni-64(p,n)Cu-64, Ac-225 via Ra-226(p,2n)Ac-225, I-124 via Te-124(p,n)I-124, and Ga-68 via Zr-68(p,n)Ga-68. These radionuclides are in high demand for their use in PET imaging and targeted radionuclide therapy (TRT).
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MPM-B.3
15:10 Characterization of DD and DT Neutron Generators at Georgia Tech NE Hertel*, Georgia Institute of Technology
; S Mukhopadhyay, Georgia Institute of Technology
Abstract: The Radiation Science and Engineering Laboratory (RSEL) at Georgia Institute of Technology has
multiple neutron sources. Among them is a Starfire DD neutron generator, a SONEX-P system which
contains a DT neutron tube, and a P211 sealed tube neutron generator. These sources are used in a variety
of manners. However, recently we have been interested in using them in experiments that required good
characterizations and dosimetry measurements. This talk will present the results of our characterizations
performed by using activation foils, a Bonner sphere spectrometer, a TEPC, and tissue equivalent ion
chambers. The potential for simulating the LET distribution of galactic cosmic rays has also been
investigated by performing LET distribution calculations of neutron-induced charged particle recoils in
tissue.
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MPM-B.4
15:30 BREAK
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MPM-B.5
15:45 High dynamic range neutron dosimetry: applications of the novel NDX dose rate meters at accelerators. PV Degtiarenko*, Jefferson Lab
Abstract: Neutron dose rate meters based on the new NDX technology are suitable for neutron measurements and monitoring in conditions of high radiation fields, including heavy photon radiation and pulsed beams. Uniform energy response function makes them applicable in high energy particle accelerators and irradiation facilities. The report will briefly describe the detectors' design and present the results of the first several months of operations of the set of NDX detectors deployed at the CEBAF high energy electron accelerator tunnel. The detectors provided real time monitoring of the radiation conditions during the operations and helped to minimize the field emission in the superconducting accelerating cryomodules, and to minimize chronic beam losses in the machine.
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MPM-B.6
16:10 An LSTM Deep Learning Network for Background Radiation Prediction A Stavola*, Thomas Jefferson National Accelerator Facility
; H Zhang, Old Dominion University; H Ferguson, Old Dominion University; P Degtiarenko, Thomas Jefferson National Accelerator Facility; J Li, Old Dominion University; C Kwan, Applied Research, LLC
Abstract: Determination of appropriate background radiation is important in any measurement application. Environmental radiation monitors and monitors used to assess dose to individuals outside of controlled areas are particularly susceptible to changes in readings due to fluctuations in the environmental conditions. These fluctuations (e.g. radon progeny concentrations) lead to changes in the detector response in the actual radiation environment, and they need to be taken into account when extracting the net operational doses. Work has been ongoing to apply advances in Deep Learning and Artificial Intelligence to account for changes in detector responses based on environmental parameters; in particular, a Long-Short Term Memory (LSTM) Deep Learning architecture has been utilized to incorporate time-series data into a prediction model. In this work, we present the current status of the project to predict radiation measurements based on meteorological conditions and air packet trajectories extracted using the National Oceanic and Atmospheric Administration's (NOAA) Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT4) model.
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MPM-B.7
16:25 Analysis of Relative Hazards and Detection Capabilities for Radionuclides at the Spallation Neutron Source JA Hillis*, Oak Ridge National Laboratory
Abstract: The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory creates the opportunity for neutron scattering research. When the SNS tunnel is opened, Radiation Control Technicians must identify contamination areas. A contamination area defined by Title 10, Code of Federal Regulations, Part 835 requires that all beta-gamma emitting radionuclides be held to the same removable surface contamination count rate standard. However, these requirements pose an obstacle for beryllium-7 (7Be). To assimilate the challenges with 7¬Be, a Monte Carlo N-Particle (MCNP) code modeling a NaI detector and the nominal background radionuclides found in the ring tunnel were simulated to verify the relative efficiency and the detectability of 7Be. The radiotoxicities calculated of each radionuclide were understood based on their respective Derived Air Concentration (DAC) values. The biological impact of each radionuclide was also examined using the Dose and Risk Calculation (DCAL) software in order to compute specific effective dose equivalents. The effective dose equivalents allowed for an analysis of the biological impact ratios of 7Be compared to other radionuclides to discern 7Be health hazards. These analyses showed the obstacles in detecting 7Be due to its low detectability, which requires an increased demand in time, money, and operations. The radiotoxicity of 7Be also showed to be a substantially lower health hazard to SNS employees than other existing radionuclides in the tunnel. This research investigates the need for a new acceptable and manageable removable surface contamination count rate for 7Be and proposes that it should not be treated the same as other beta-gamma emitting radionuclides due to its low detectability and low health concerns.
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MPM-B.8
16:40 High Power Beam Dump Shielding Design for the LCLS-II-HE Low Emittance Injector A Rosenstrom*, Georgia Institute of Technology & SLAC National Accelerator Laboratory
; M Santana, SLAC National Accelerator Laboratory; S Dewji, Georgia Institute of Technology
Abstract: The Low Emittance Injector (LEI) will extend the energy range and intensity of the free-electron-laser of the Linear Coherent Light Source Two (LCLS-II) at SLAC National Accelerator Laboratory. The LEI will be housed in a parallel tunnel to the LCLS-II tunnel and make use of existing cryogenic infrastructure. In order to ensure continued operation of the LCLS-II during the commissioning and diagnostic operation of the LEI, a diagnostic beam dump will be located in the LEI tunnel. In order to better protect workers accessing the tunnel during the commissioning period, as well as those in accessible areas outside of the tunnel, a new design of dumpline beam optics was created. The LEI beam dump line utilizes a common beamline optics feature, a so-called “dogleg,” in a novel application. The efficacy of this design is demonstrated when compared to a standard layout that utilizes a single bend by reducing the residual and prompt radiation in the tunnel floor by almost 3 and 5 orders of magnitude, respectively, while not drastically increasing the space claim of the dump shielding. The reduction in prompt and residual radiation has further secondary benefits of reduced electronics damage, activation of beamline components and activation are minimized as well as improving diagnostic measurements. This approach is not specific to this facility and could be applied to compactly and effectively shield high-power sub-GeV beam dumps in many accelerator facilities.
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MPM-B.9
16:55 Section Meeting
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