The CLAS12 Geant4 simulation Ungaro, M.; Angelini, G.; Battaglieri, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2020, Volume:
959, Issue:
C
Journal Article
Peer reviewed
Open access
The Geant4 Monte-Carlo (GEMC) package is used to simulate the passage of particles through the various CLAS12 detectors. The geometry is implemented through a database of Geant4 volumes created ...either through the GEMC native API, by the CLAS12 geometry service, or imported from the CAD engineering model. The truth information is digitized with a plugin mechanism by routines specific to each detector and includes the use of the CLAS12 calibration database constants to produce both ADC and TDC response functions. Theoretical models that produce the generated events interface with GEMC through the LUND data format. The merging of simulated data with real random trigger data provides a mechanism to include both beam and electronic background into the simulation of generated events to accurately model beam data from the CLAS12 detector. The performance of simulation is demonstrated by comparison with the experimental data.
The Thomas Jefferson National Accelerator Facility (JLab) has designed a unique spectrometer system to measure the weak interaction between electrons. The experiment- Measurement of Lepton-Lepton ...Electroweak Reaction (MOLLER)-requires leveraging the recent 12 GeV electron beam upgrade and will run in JLab for three years. Focusing the signal for the MOLLER experiment requires five water-cooled toroidal magnets, each with unique geometry and with 7-fold symmetry. The five magnets operate in a vacuum and provide the magnetic field required to separate the incident beam electrons scattered from the target electrons (Møller scattering) and protons (elastic e-p scattering) in a liquid hydrogen target. The conceptual design was developed by the MOLLER Collaboration and was given to JLab in the form of amp turns and physical location, with additional physics requirements. This article presents prototyping of the coils and magnet support system and discusses the lessons learned during the process along with the plans for full magnet testing and installation. The JLab Magnet Group along with the MOLLER Collaboration developed the specification document that includes keep out zones to design the set of magnets. JLab contracted the design of the first toroid magnet (TM0) of the magnet system to Massachusetts Institute of Technology. The other four toroid magnets (TM1 through TM4) have been designed by JLab and are in the process of fabrication and assembly. Prototype coils of TM1-TM4 were fabricated by Everson-Tesla Incorporated, PA (USA). This article presents the unique challenges of the design, alignment, high current density, operating range, high radiation dose, and vacuum environment.
This is an extension of the work on a multi-scale nonlinear procedure that demonstrated how to conduct nonlinear stress analysis of Nb 3 Sn superconducting accelerator magnets. The nonlinear ...procedure uses measured stress-strain curves of annealed copper, Nb 3 Sn strands and coil samples as inputs, which reduces the number of assumptions made for material properties-key uncertainties of any engineering analysis. The results from nonlinear analysis, semi-nonlinear analysis, and linear analysis of the same QFFB2 Nb 3 Sn quadrupole magnet under the same temperature and loads, were compared and discussed. The comparison illustrates that nonlinear stress analysis is significantly more accurate than other methods. As the superconducting coil block is a complex, composite material, it would be inadequate to assume the whole coil block to be linear, either isotropic or orthotropic. It is imperative to conduct nonlinear analysis by simulating the superconducting coil to the level of detail of the individual cables and individual strands. The nonlinear stress analysis procedure can be used to simulate not only Nb 3 Sn magnets, but also NbTi and HTS magnets.
Large Scale Superconducting Wind Turbine Cooling Stautner, W.; Fair, R.; Sivasubramaniam, K. ...
IEEE transactions on applied superconductivity,
06/2013, Volume:
23, Issue:
3
Journal Article, Conference Proceeding
Peer reviewed
General Electric proposes to apply transformational technology in the form of low-temperature superconductivity to the design of direct-drive wind turbine generators of the 10-MW power level and ...greater. Generally, optimal steady state 4 K cryogenic cooling of a large thermal mass (> 10 000 kg) and its dimensions (> 4 m diameter and 2.5 m length) with minimum levelized cost of energy is difficult to achieve. A cooling strategy has been found that turns this size disadvantage to ones favor, and furthermore enables the design scalability of the field winding cooling assembly towards 15 to 20 MW. In this design study, we show that size and efficiency are not mutually exclusive and that it is indeed possible to minimize cryogenic complexity and reduce cost. The cryogenic push-button closed loop circulating system is invisible within the nacelle of a wind turbine and requires no handling of cryogenic liquids. Besides the occasional cryocooler service requirement, the proposed solution is maintenance-free in all operating states and allows the system health to be monitored remotely. The design solutions proposed could potentially make large superconducting generators a reality for off-shore wind turbine deployment.
The Thomas Jefferson National Accelerator Facility (JLab) has designed a unique spectrometer system to measure the weak interaction between electrons. The experiment- Measurement of Lepton-Lepton ...Electroweak Reaction (MOLLER)- requires leveraging the recent 12 GeV electron beam upgrade and will run in JLab for 3 years. Focusing the signal for the MOLLER experiment requires five water-cooled toroidal magnets, each with unique geometry and with 7-fold symmetry. This system of magnets provides the magnetic field required to separate the incident beam electrons scattered from the target electrons (Møller scattering) and protons (elastic e-p scattering) in a liquid hydrogen target. The conceptual design was developed by the MOLLER collaboration and was given to JLab in the form of amp turns and physical location, with additional physics requirements. This paper presents prototyping of the coils and magnet support system and discusses the lessons learned during the process along with the plans for full magnet testing and installation. The JLab Magnet Group along with the MOLLER collaboration developed the specification document that includes keep out zones to design the set of magnets. JLab contracted the design of the first toroid magnet in the magnet (TM0) to Massachusetts Institute of Technology. The other four toroid magnets (TM1 through TM4) have been designed by JLab and are in the process of fabrication and assembly. Prototype coils of TM1-TM4 have been fabricated by Everson-Tesla Incorporated, PA (USA). In conclusion, the manuscript presents the unique challenges of the design, alignment, high current density, operating range, high radiation dose, and vacuum environment.
The CLAS12 superconducting magnets Fair, R.; Baltzell, N.; Bachimanchi, R. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2020, Volume:
962, Issue:
C
Journal Article
Peer reviewed
Open access
As part of the Jefferson Lab 12 GeV upgrade, the Hall B CLAS12 system requires two superconducting iron-free magnets — a torus and a solenoid. The physics requirements to maximize space for the ...detectors guided engineers toward particular coil designs for each of the magnets which, in turn, led to the choice of using conduction cooling. The torus consists of 6 trapezoidal NbTi coils connected in series with an operating current of 3770 A. The solenoid is an actively shielded 5 T magnet consisting of 5 NbTi coils connected in series operating at 2416 A. Within the hall, the two magnets are located in close proximity to each other and are completely covered both inside and outside by particle detectors. Stringent size limitations were imposed for both magnets and introduced particular design and fabrication challenges. This paper describes the design, construction, installation, commissioning, and operation of the two magnets.
The Jefferson Lab 12 GeV Upgrade in Hall B will need CLAS12 detector that requires two superconducting magnets. One is a magnet system consisting of six superconducting trapezoidal racetrack-type ...coils assembled in a Toroidal configuration (Torus) and the second is an actively shielded solenoidal magnet (Solenoid). Both the torus and solenoid are located in close proximity to one another and are surrounded by sensitive detectors. This paper investigates the electromagnetic interactions between the two systems during normal operation as well as during various fault scenarios as part of a Risk Assessment and Mitigation (RAM).
As part of the Jefferson Lab 12 GeV accelerator upgrade project, Hall B requires two conduction cooled superconducting magnets. One is a magnet system consisting of six superconducting trapezoidal ...racetrack-type coils assembled in a toroidal configuration and the second is an actively shielded solenoidal magnet system consisting of five coils. Both magnets are to be wound with Superconducting Super Collider-36 NbTi strand Rutherford cable soldered into a copper channel. This paper describes This paper describes a failure modes and effects analysis (FMEA) that was done on these magnets to identify their various failure modes, which were assessed in terms of their Risk Priority Numbers (RPN). Mitigating actions were identified that would reduce the RPNs to acceptable values.
The CLAS12 superconducting magnets Fair, R.; Baltzell, N.; Bachimanchi, R. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2020, Volume:
962, Issue:
C
Journal Article
Peer reviewed
Open access
As part of the Jefferson Lab 12 GeV upgrade, the Hall B CLAS12 system requires two superconducting iron-free magnets — a torus and a solenoid. The physics requirements to maximize space for the ...detectors guided engineers toward particular coil designs for each of the magnets which, in turn, led to the choice of using conduction cooling. The torus consists of 6 trapezoidal NbTi coils connected in series with an operating current of 3770 A. The solenoid is an actively shielded 5 T magnet consisting of 5 NbTi coils connected in series operating at 2416 A. Within the hall, the two magnets are located in close proximity to each other and are completely covered both inside and outside by particle detectors. Stringent size limitations were imposed for both magnets and introduced particular design and fabrication challenges. This paper describes the design, construction, installation, commissioning, and operation of the two magnets.
Trial coil winding of full size coils for the Q1 magnet of the Super High Momentum Spectrometer (SHMS) for JLAB Hall C has been performed under contract by Scientific Magnets Inc. This effort was ...required to demonstrate that the unique Q1 cold iron quadrupole shape can be executed with a Rutherford type SC cable. Details of the prototype winding tooling, conductor insulation scheme, coil former, the winding process including clamping and curing will be presented. Lessons learned from the initial set of windings were incorporated into the final trail windings of two complete full scale coils that can potentially be used in the actual magnet fabrication. The initial trial windings indicted that the coil end turns would benefit from additional support in the winding form and inclusion of a 5 degree shim along the first turn of the coil would be helpful in improving the fit up of the coils on the symmetry planes, leading to an improved end shape. These changes in coil shape were modeled in TOSCA and the resultant magnetic properties confirmed. The Q1 coils wound were tested for electrical properties, insulation effectiveness and dimensional consistency. Results from the three coils wound will be presented.
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