A Compact Gas Liquid Separator for the SNS Mercury Process Loop

2021 ◽  
Author(s):  
Charlotte Barbier ◽  
Elvis Dominguez-Ontiveros ◽  
Justin Weinmeister ◽  
Jeremy Slade ◽  
Dustin Ottinger ◽  
...  
Keyword(s):  
Proton Beam ◽  
Pressure Wave ◽  
National Laboratory ◽  
Beam Power ◽  
Target Station ◽  
Pressure Losses ◽  
Oak Ridge ◽  
Helium Bubbles ◽  
Successful Design ◽  
Liquid Separator

Abstract Upgrades at the Spallation Neutron Source (SNS) accelerator at Oak Ridge National Laboratory are underway to double its proton beam power from 1.4 to 2.8 MW. About 2MW will go to the current first station while the rest will go to the future Second Target Station. The increase of beam power to the first target station is especially challenging for its mercury target. When the short proton beam hits the target, strong pressure waves are generated, causing cavitation erosion and challenging stresses for the target's weld regions. SNS has successfully operated reliably at 1.4 MW by mitigating the pressure wave with the injection of small Helium bubbles into the mercury. To operate reliably at 2MW, more gas will be injected into mercury to mitigate the pressure wave further. However, the mercury process loop was not originally designed for gas injection, and the accumulation of gas in the pipes is a concern. Due to space constraints, a custom Gas Liquid Separator (GLS) was designed to fit a 90-degree horizontal elbow space in the SNS mercury loop. Simulations and experiments were performed, and a successful design was developed that has the desired efficiency while keeping the pressure losses acceptable.

scholarly journals Neutronics analyses for the conceptual design of the SNS Second Target Station

2020 ◽  
Vol 22 (2-3) ◽  
pp. 265-273
Author(s):  
Igor Remec ◽  
Franz X. Gallmeier
Keyword(s):  
Proton Beam ◽  
Conceptual Design ◽  
Neutron Source ◽  
Cross Sections ◽  
Energy Deposition ◽  
National Laboratory ◽  
Spallation Neutron Source ◽  
Target Station ◽  
Oak Ridge ◽  
Residual Heat

The Spallation Neutron Source, in operation at the Oak Ridge National Laboratory since 2006, was designed to allow the addition of a second target station and an upgrade of the accelerator proton power. Both upgrades are now underway. This paper describes the evolution of the design of the target of the second target station with the emphasis on the effects of the proton beam footprint on the energy deposition in the target, stresses induced by the pulsed operation, and the importance of the residual heat. The moderator configurations and their optimization are discussed. With the utilization of pure parahydrogen moderators, small neutron beam cross-sections, and the specific optimization, neutron beams of the second target station will achieve exceptionally high peak brightness and time-averaged brightness.

scholarly journals EMuS Muon Facility and Its Application in the Study of Magnetism

2018 ◽  
Vol 2 (4) ◽  
pp. 23 ◽  
Author(s):  
Jingyu Tang ◽  
Xiaojie Ni ◽  
Xiaoyan Ma ◽  
Huiqian Luo ◽  
Yu Bao ◽  
...  
Keyword(s):  
Phase I ◽  
Proton Beam ◽  
Beam Power ◽  
Spallation Neutron Source ◽  
High Momentum ◽  
Multidisciplinary Research ◽  
Collection Method ◽  
Target Station ◽  
Muon Facility ◽  
Core Part

A muon facility—EMuS (Experimental Muon Source)—at China Spallation Neutron Source (CSNS) has been studied since 2007. CSNS, which is designed to deliver a proton beam power of 100 kW at Phase-I, and will serve multidisciplinary research based on neutron scattering techniques, has just completed construction, and is ready to open to general users from September 2018. As an additional platform to CSNS, EMuS aims to provide different muon beams for multiple applications, among which, magnetism study by μSR techniques is a core part. By using innovative designs, such as a long target in conical shape situating in superconducting capture solenoids and forward collection method, EMuS can provide very intense muon beams with a proton beam of 5 kW and 1.6 GeV, from surface muons, decay muons, and high momentum muons to slow muons. In this article, the design aspects of EMuS, including general design, target station, muon beamlines, and μSR spectrometer, as well as prospects for applications on magnetism studies, will be reviewed.

Numerical and Experimental Investigation of the Flow in the SNS Jet Flow Target

2015 ◽  
Author(s):  
Charlotte Barbier ◽  
Mark Wendel ◽  
David Felde ◽  
Michael C. Daugherty
Keyword(s):  
Numerical Simulations ◽  
Radiation Transport ◽  
Fluid Dynamic ◽  
National Laboratory ◽  
Jet Flow ◽  
Numerical Approach ◽  
General Purpose ◽  
Temperature Fields ◽  
Beam Power ◽  
Oak Ridge

Computational Fluid Dynamic (CFD) numerical simulations were performed for the flow inside the Spallation Neutron Source jet-flow target vessel at Oak Ridge National Laboratory. Different flow rates and beam conditions were tested to cover all the functioning range of the target, but for brevity, only the nominal case with a mass flow rate of 185 kg/s and a beam power of 1.54MW is presented here. The heat deposition rate from the proton beam was computed using the general-purpose Monte Carlo radiation transport code MCNPX and the commercial CFD code ANSYS-CFX was used to determine the flow velocity in the mercury and the temperature fields in both the mercury and the stainless steel vessel. Boundary conditions, turbulence model and mesh effects are presented in depth. To validate the numerical approach, Particle Imagery Velocimetry (PIV) measurements on a water-loop setup with an acrylic jet-flow target mock-up were performed and compared to the numerical simulations. It was found that a sustained wall jet was developed across the whole length of the vulnerable surface, confirming the good design of the jet-flow target. Overall, good agreements were observed between the experiments and the simulations: the velocity contours and the shape of the recirculation zone near the side baffle are qualitatively similar. However, some differences were also observed that underlines the shortcomings of both the numerical simulations and the experimental measurements.

Gas Wall Layer Experiments for SNS Target

2019 ◽  
Author(s):  
Justin R. Weinmeister ◽  
Elvis E. Dominguez-Ontiveros ◽  
Charlotte N. Barbier
Keyword(s):  
Cavitation Erosion ◽  
National Laboratory ◽  
Gas Injection ◽  
Wall Layer ◽  
Test Facility ◽  
Beam Power ◽  
Shear Stresses ◽  
Oak Ridge ◽  
Area Of Interest ◽  
Erosion Mitigation

Abstract The Proton Power Upgrade (PPU) project will increase the proton beam power at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL), requiring new cavitation erosion mitigation techniques for the mercury target vessel. More precisely, a gas wall layer will be injected on the wall surface where heavy cavitation erosion is observed. In this paper, a series of experiments were performed to develop a gas layer on a simplified target geometry. First, experiments in water were used to test a prototype injection strategy in a simplified target nose geometry. Then the experiment was repeated at the Target Test Facility (TTF) at ORNL where mercury wass flowed in the same geometry. Observations showed that gas injection into liquid metal was much more sensitive to flow velocity than in water. Ultimately, the experiments showed the gas injection must be located very close to the area of interest in a non-intrusive configuration to reduce shear stresses in the flow for good gas coverage. This technique will be next implemented in a more prototypical target.

scholarly journals Small Bubbles Generation With Swirl Bubblers for SNS Target

2018 ◽  
Author(s):  
C. Barbier ◽  
E. Dominguez-Ontiveros ◽  
R. Sangrey
Keyword(s):  
Pressure Wave ◽  
Proton Accelerator ◽  
Pressure Waves ◽  
Negative Effects ◽  
Cavitation Damage ◽  
Pressure Losses ◽  
Oak Ridge ◽  
Micron Diameter ◽  
Rapid Temperature ◽  
Small Bubbles

Oak Ridge National Laboratory’s (ORNL) Spallation Neutron Source (SNS) uses a mercury target to generate neutrons. When the powerful 1.4 MW, 60Hz proton beam hits the target, a strong pressure wave propagates in the mercury and into the vessel wall due to the rapid temperature rise in mercury. These pressure waves induce cavitation damage on the target container and high stresses, which both limit the lifetime of the target. Since October 2017, helium gas has been injected into the mercury flow in order to mitigate the negative effects of pulse-induced pressure waves. The preliminary strain measurements suggest that gas injection is indeed efficient at mitigating the pressure wave. Tiny nozzles (8-micron diameter) at choked condition are used to generate small bubbles. The bubblers can theoretically inject a total mass flow rate of 0.75 SLPM. However, during operation the bubblers were capable of injecting only approximately 0.45 SLPM, which suggests that some of the nozzles may have become clogged. Since there is a strong desire to inject a larger quantity of gas in the target to, hopefully, mitigate even more the pressure wave, SNS has been looking at implementing swirl bubblers in the target, similar to the ones used in the Japan Proton Accelerator Research Complex (J-PARC) mercury target. In this paper, results with prototypical bubblers tested in water and mercury are presented. Bubblers were installed in prototypical targets and bubble size distributions were measured in both water and mercury. It was found that swirl bubblers can generate a large number of small bubbles, but some compromises were made to keep the pressure losses across them reasonable.

Plug-in scripts for EFTEM automation

1996 ◽  
Vol 54 ◽  
pp. 546-547
Author(s):  
N. D. Evans ◽  
M. K. Kundmann
Keyword(s):  
Electron Microscopy ◽  
National Laboratory ◽  
Oak Ridge ◽  
Multiple User ◽  
Transmission Electron ◽  
Short Period ◽  
User Facility ◽  
Instrument Control ◽  
And Control ◽  
Research Equipment

Post-column energy-filtered transmission electron microscopy (EFTEM) is inherently challenging as it requires the researcher to setup, align, and control both the microscope and the energy-filter. The software behind an EFTEM system is therefore critical to efficient, day-to-day application of this technique. This is particularly the case in a multiple-user environment such as at the Shared Research Equipment (SHaRE) User Facility at Oak Ridge National Laboratory. Here, visiting researchers, who may oe unfamiliar with the details of EFTEM, need to accomplish as much as possible in a relatively short period of time.We describe here our work in extending the base software of a commercially available EFTEM system in order to automate and streamline particular EFTEM tasks. The EFTEM system used is a Philips CM30 fitted with a Gatan Imaging Filter (GIF). The base software supplied with this system consists primarily of two Macintosh programs and a collection of add-ons (plug-ins) which provide instrument control, imaging, and data analysis facilities needed to perform EFTEM.

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