The new SNS Allison emittance scanner measures emittances of 65 kV ion beams over a range of +/- ... more The new SNS Allison emittance scanner measures emittances of 65 kV ion beams over a range of +/- 116 mrad. Its versatile control system allows for time-dependent emittance measurements using an external trigger to synchronize with pulsed ion beam systems. After an adjustable initial delay, the system acquires an array of equally-delayed beam current measurements, each averaged over a certain time span, where all three time parameters are user selectable. The zero offset of the beam current measurements is determined by averaging a fraction of 1 ms shortly before the start of the ion beam pulse. This paper discusses the optimization of the angular range. In addition it presents the first results and reports an unresolved artefact. Data are presented on the time evolution of emittance ellipses during 0.8 ms long H- beam pulses emerging from the SNS test LEBT, which is important for loss considerations in the SNS accelerator. Additional data explore the emittance growth observed with i...
Space charge effects, beam losses, wake fields, and orbital control are significant collective ef... more Space charge effects, beam losses, wake fields, and orbital control are significant collective effects that affect beam dynamics. The strong-focusing cyclotron incorporates helical orbits with a strong-focusing lattice and high-gradient cavities. It makes it possible to fully separate orbits and suppress interaction between bunches on neighboring orbits. We simulate nonlinear synchrobetratron coupling and explore methods to use the tools of strong-focusing to suppress beam blowup mechanisms.
New information on magnetic fluctuations and transport in toroidal devices has been obtained in t... more New information on magnetic fluctuations and transport in toroidal devices has been obtained in the MST reversed field pinch through measurement of nonlinear coupling of three waves in k-space, and measurement of current density fluctuations. Measurements of nonlinear coupling of magnetic fluctuations reveals that (1) two poloidal mode number m = 1 modes couple strongly to an m = 2
Physical Review Special Topics - Accelerators and Beams, 2007
The Laser-Stripping project has been a central focus in my career for two years, and there are ma... more The Laser-Stripping project has been a central focus in my career for two years, and there are many people to thank, many of whom were necessary for this work to be possible. I would like to thank my wife, Sharon, and my daughter, Amelia, for their endless patience with me while I spent the necessary time in school for two weeks at a time, and extra work hours put in for the project at work. Thank you to Stuart Henderson and Saeed Assadi for allowing me to work on the Laser project at the Spallation Neutron Source at the Oak Ridge National Laboratory. For their encouragement and guidance as I struggled to maintain focus while juggling a busy work schedule, I will forever be indebted. In addition, I would like to thank Viatcheslav Danilov, Warren Grice, and Yun Liu for their contributions to the project in general and their contributions to my informal education in the Accelerator Physics and the Laser Physics aspects of the project. I would be remiss if I failed to mention William Barletta, Helmut Wiedemann, and S.Y. Lee, past and present directors of the USPAS, Susan Winchester, and Marilyn Paul, staff of the USPAS office, and all of the USPAS instructors for offering the opportunity for such an endeavor and the unrelenting desire to see students of the USPAS succeed. Last, but certainly not least, a special thanks goes out to my immediate supervisors and coworkers who have worked diligently to ensure my attendance at the USPAS courses was not impeded, and that I had sufficient time to donate to special projects like the Laser-Stripping experiment.
Results are presented from end-to-end simulation of a 100 MeV strong focusing cyclotron (SFC). Th... more Results are presented from end-to-end simulation of a 100 MeV strong focusing cyclotron (SFC). The development of the high-current SFC is motivated by applications for production of medical isotopes and for a proton driver for subcritical fission. It uses a novel superconducting cavity to provide sufficient energy gain to fully separate all turns. An arc-contour F-D doublet, trim dipole winding, and sextupole are located along each turn within the aperture of each sector dipole to control the betatron and synchrotron motion and to stabilize non-linear dynamics with high-current operation. The phase space evolution of a proton bunch in the SFC was simulated using both the code OPAL and an ad hoc Runge-Kutta tracker. Iterative optimization of the dipole, quadrupole, and sextupole fields was used to provide precise isochronicity, favorable betatron phase advance, and cancellation of disper-
The Accelerator Research Lab at Texas A&M University is developing new accelerator technology for... more The Accelerator Research Lab at Texas A&M University is developing new accelerator technology for a high-brightness, high-current cyclotron with capabilities that will be beneficial for applications to accelerator-driven subcritical fission, medical isotope production, and proton therapy. As a first embodiment of the technology, we are developing a detailed design for TAMU-50, a 50 MeV, 5 mA proton cyclotron with high beam brightness. In this presentation we present devices and beamline components for injection, extraction, controls and diagnostics. We emphasize the system integration and implementation of TAMU-50 for production of medical radioisotopes.
This report was prepared as an account of work sponsored by an agency of the United States Govern... more This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States nor any agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for any third party's use or the results of such use of any information, apparatus, product or process disclosed in this report, or represents that its use by such third party would not infringe privately owned rights.
A design is presented for a hadron collider in which the magnetic storage ring is configured as a... more A design is presented for a hadron collider in which the magnetic storage ring is configured as a circular pipeline, supported in neutral buoyancy in the sea at a depth of ~100 m. Each collider detector is housed in a bathysphere the size of the CMS hall at LHC, also neutral-buoyant. Each half-cell of the collider lattice is ~300 m long, housed in a single pipe that contains one dipole, one quadrupole, a correction package, and all umbilical connections. A choice of ~4 T dipole field, 2000 km circumference provides a collision energy of 700 TeV. Beam dynamics is dominated by synchrotron radiation damping, which sustains luminosity for >10 hours. Issues of radiation shielding and abort can be accommodated inexpensively. There are at least ten sites world-wide where the collider could be located, all near major urban centers. The paper summarizes several key issues; how to connect and disconnect half-cell segments of the pipeline at-depth using remote submersibles; how to maintain ...
Frontiers in Optics 2008/Laser Science XXIV/Plasmonics and Metamaterials/Optical Fabrication and Testing, 2008
A laser-based diagnostics system is implemented in the SNS superconducting accelerator. The syste... more A laser-based diagnostics system is implemented in the SNS superconducting accelerator. The system measures the Hbeam profiles at 9 different energy levels (200 MeV-1 GeV) using a single laser.
The strong-focusing cyclotron is an isochronous sector cyclotron in which slot-geometry supercond... more The strong-focusing cyclotron is an isochronous sector cyclotron in which slot-geometry superconducting half-cell cavities are used to provide sufficient energy gain per turn to fully separate orbits and superconducting quadrupoles are located in the aperture of each sector dipole to provide strong focusing and control betatron tune. The SFC offers the possibility to address the several effects that most limit beam current in a CW cyclotron: space charge, bunch-bunch interactions, resonance-crossing, and wake fields. Simulation of optical transport and beam dynamics entails several new challenges: the combined-function fields in the sectors must be properly treated in a strongly curving geometry, and the strong energy gain induces continuous mixing of horizontal betatron and synchrotron phase space. We present a systematic simulation of optical transport using modified versions of MAD-X and SYNERGIA. We report progress in introducing further elements that will set the stage for stud...
The Strong Focusing Cyclotron development at Texas A&M University has evolved from stacks of cycl... more The Strong Focusing Cyclotron development at Texas A&M University has evolved from stacks of cyclotrons to a single layer high brightness, low emittance device to produce greater than 10 mA of proton beam to a desired target at 800 MeV. The latest design has a major geometric design optimization of strong focusing quadrupoles and a modified algorithm of high gradient cavities. These optimizations address the turn separation and interaction of radially neighbouring bunches and produced a reduced the number of turns necessary to reach the desired final energy under control conditions. In this paper, we present the new design, the physics of nonlinear synchrobetratron coupling, mνh+nνv=p causing beam blow-up in other form of cyclotrons and how this work has resolved it. The cavity beam loading, and space charge effects of multi turns at low energies to reduce losses, are discussed.
An adaptable architecture of a machine protection system (MPS) suitable for continuous wave (CW),... more An adaptable architecture of a machine protection system (MPS) suitable for continuous wave (CW), high intensity accelerators like those proposed for Accelerator Driven Systems (ADS) for subcritical reactor strategies and heavy ion accelerators for the production of rare isotopes is presented. A system of databases, networks and nodes that can systematically and flexibly be reconfigured to rebalance the required metadata is used. Additional features include reconfigurable machine setup templates that can rigorously be tested with mirror redundant online backups, the utilization of external reconfigurable geometric algorithms for the data channels and the network distribution, and the inclusion of initial system requirements as well as envisioned upgrades.
Suggestions have been made for a 80-100 km circumference Future Circular Collider (FCC) that coul... more Suggestions have been made for a 80-100 km circumference Future Circular Collider (FCC) that could ultimately contain a circular e+e- ring collider operating as a Higgs Factory as well as a 100 TeV hadron collider. Those suggestions have motivated us to propose an approach in which the project is sited at the location at the SSC tunnel, which has the lowest tunnel cost ever. The low tunnel cost would make it cost-effective to locate the 100 TeV Hadron Collider in a 270 km circumference tunne, using 4.5 Tesla superconducting magnets. The SSC tunnel itself would be used to house the Higgs Factory and the injector for the Hadron Collider. The injector for the Higgs Factory would be also used as a driver for an X-ray Free Electron Laser with unique capabilities for protein crystallography. The location of the project at a location with favorable geotechnology for minimum-cost tunneling, and low-cost/low-risk technology for the SRF and superconducting magnets, open the possibility to bui...
The new SNS Allison emittance scanner measures emittances of 65 kV ion beams over a range of +/- ... more The new SNS Allison emittance scanner measures emittances of 65 kV ion beams over a range of +/- 116 mrad. Its versatile control system allows for time-dependent emittance measurements using an external trigger to synchronize with pulsed ion beam systems. After an adjustable initial delay, the system acquires an array of equally-delayed beam current measurements, each averaged over a certain time span, where all three time parameters are user selectable. The zero offset of the beam current measurements is determined by averaging a fraction of 1 ms shortly before the start of the ion beam pulse. This paper discusses the optimization of the angular range. In addition it presents the first results and reports an unresolved artefact. Data are presented on the time evolution of emittance ellipses during 0.8 ms long H- beam pulses emerging from the SNS test LEBT, which is important for loss considerations in the SNS accelerator. Additional data explore the emittance growth observed with i...
Space charge effects, beam losses, wake fields, and orbital control are significant collective ef... more Space charge effects, beam losses, wake fields, and orbital control are significant collective effects that affect beam dynamics. The strong-focusing cyclotron incorporates helical orbits with a strong-focusing lattice and high-gradient cavities. It makes it possible to fully separate orbits and suppress interaction between bunches on neighboring orbits. We simulate nonlinear synchrobetratron coupling and explore methods to use the tools of strong-focusing to suppress beam blowup mechanisms.
New information on magnetic fluctuations and transport in toroidal devices has been obtained in t... more New information on magnetic fluctuations and transport in toroidal devices has been obtained in the MST reversed field pinch through measurement of nonlinear coupling of three waves in k-space, and measurement of current density fluctuations. Measurements of nonlinear coupling of magnetic fluctuations reveals that (1) two poloidal mode number m = 1 modes couple strongly to an m = 2
Physical Review Special Topics - Accelerators and Beams, 2007
The Laser-Stripping project has been a central focus in my career for two years, and there are ma... more The Laser-Stripping project has been a central focus in my career for two years, and there are many people to thank, many of whom were necessary for this work to be possible. I would like to thank my wife, Sharon, and my daughter, Amelia, for their endless patience with me while I spent the necessary time in school for two weeks at a time, and extra work hours put in for the project at work. Thank you to Stuart Henderson and Saeed Assadi for allowing me to work on the Laser project at the Spallation Neutron Source at the Oak Ridge National Laboratory. For their encouragement and guidance as I struggled to maintain focus while juggling a busy work schedule, I will forever be indebted. In addition, I would like to thank Viatcheslav Danilov, Warren Grice, and Yun Liu for their contributions to the project in general and their contributions to my informal education in the Accelerator Physics and the Laser Physics aspects of the project. I would be remiss if I failed to mention William Barletta, Helmut Wiedemann, and S.Y. Lee, past and present directors of the USPAS, Susan Winchester, and Marilyn Paul, staff of the USPAS office, and all of the USPAS instructors for offering the opportunity for such an endeavor and the unrelenting desire to see students of the USPAS succeed. Last, but certainly not least, a special thanks goes out to my immediate supervisors and coworkers who have worked diligently to ensure my attendance at the USPAS courses was not impeded, and that I had sufficient time to donate to special projects like the Laser-Stripping experiment.
Results are presented from end-to-end simulation of a 100 MeV strong focusing cyclotron (SFC). Th... more Results are presented from end-to-end simulation of a 100 MeV strong focusing cyclotron (SFC). The development of the high-current SFC is motivated by applications for production of medical isotopes and for a proton driver for subcritical fission. It uses a novel superconducting cavity to provide sufficient energy gain to fully separate all turns. An arc-contour F-D doublet, trim dipole winding, and sextupole are located along each turn within the aperture of each sector dipole to control the betatron and synchrotron motion and to stabilize non-linear dynamics with high-current operation. The phase space evolution of a proton bunch in the SFC was simulated using both the code OPAL and an ad hoc Runge-Kutta tracker. Iterative optimization of the dipole, quadrupole, and sextupole fields was used to provide precise isochronicity, favorable betatron phase advance, and cancellation of disper-
The Accelerator Research Lab at Texas A&M University is developing new accelerator technology for... more The Accelerator Research Lab at Texas A&M University is developing new accelerator technology for a high-brightness, high-current cyclotron with capabilities that will be beneficial for applications to accelerator-driven subcritical fission, medical isotope production, and proton therapy. As a first embodiment of the technology, we are developing a detailed design for TAMU-50, a 50 MeV, 5 mA proton cyclotron with high beam brightness. In this presentation we present devices and beamline components for injection, extraction, controls and diagnostics. We emphasize the system integration and implementation of TAMU-50 for production of medical radioisotopes.
This report was prepared as an account of work sponsored by an agency of the United States Govern... more This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States nor any agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for any third party's use or the results of such use of any information, apparatus, product or process disclosed in this report, or represents that its use by such third party would not infringe privately owned rights.
A design is presented for a hadron collider in which the magnetic storage ring is configured as a... more A design is presented for a hadron collider in which the magnetic storage ring is configured as a circular pipeline, supported in neutral buoyancy in the sea at a depth of ~100 m. Each collider detector is housed in a bathysphere the size of the CMS hall at LHC, also neutral-buoyant. Each half-cell of the collider lattice is ~300 m long, housed in a single pipe that contains one dipole, one quadrupole, a correction package, and all umbilical connections. A choice of ~4 T dipole field, 2000 km circumference provides a collision energy of 700 TeV. Beam dynamics is dominated by synchrotron radiation damping, which sustains luminosity for >10 hours. Issues of radiation shielding and abort can be accommodated inexpensively. There are at least ten sites world-wide where the collider could be located, all near major urban centers. The paper summarizes several key issues; how to connect and disconnect half-cell segments of the pipeline at-depth using remote submersibles; how to maintain ...
Frontiers in Optics 2008/Laser Science XXIV/Plasmonics and Metamaterials/Optical Fabrication and Testing, 2008
A laser-based diagnostics system is implemented in the SNS superconducting accelerator. The syste... more A laser-based diagnostics system is implemented in the SNS superconducting accelerator. The system measures the Hbeam profiles at 9 different energy levels (200 MeV-1 GeV) using a single laser.
The strong-focusing cyclotron is an isochronous sector cyclotron in which slot-geometry supercond... more The strong-focusing cyclotron is an isochronous sector cyclotron in which slot-geometry superconducting half-cell cavities are used to provide sufficient energy gain per turn to fully separate orbits and superconducting quadrupoles are located in the aperture of each sector dipole to provide strong focusing and control betatron tune. The SFC offers the possibility to address the several effects that most limit beam current in a CW cyclotron: space charge, bunch-bunch interactions, resonance-crossing, and wake fields. Simulation of optical transport and beam dynamics entails several new challenges: the combined-function fields in the sectors must be properly treated in a strongly curving geometry, and the strong energy gain induces continuous mixing of horizontal betatron and synchrotron phase space. We present a systematic simulation of optical transport using modified versions of MAD-X and SYNERGIA. We report progress in introducing further elements that will set the stage for stud...
The Strong Focusing Cyclotron development at Texas A&M University has evolved from stacks of cycl... more The Strong Focusing Cyclotron development at Texas A&M University has evolved from stacks of cyclotrons to a single layer high brightness, low emittance device to produce greater than 10 mA of proton beam to a desired target at 800 MeV. The latest design has a major geometric design optimization of strong focusing quadrupoles and a modified algorithm of high gradient cavities. These optimizations address the turn separation and interaction of radially neighbouring bunches and produced a reduced the number of turns necessary to reach the desired final energy under control conditions. In this paper, we present the new design, the physics of nonlinear synchrobetratron coupling, mνh+nνv=p causing beam blow-up in other form of cyclotrons and how this work has resolved it. The cavity beam loading, and space charge effects of multi turns at low energies to reduce losses, are discussed.
An adaptable architecture of a machine protection system (MPS) suitable for continuous wave (CW),... more An adaptable architecture of a machine protection system (MPS) suitable for continuous wave (CW), high intensity accelerators like those proposed for Accelerator Driven Systems (ADS) for subcritical reactor strategies and heavy ion accelerators for the production of rare isotopes is presented. A system of databases, networks and nodes that can systematically and flexibly be reconfigured to rebalance the required metadata is used. Additional features include reconfigurable machine setup templates that can rigorously be tested with mirror redundant online backups, the utilization of external reconfigurable geometric algorithms for the data channels and the network distribution, and the inclusion of initial system requirements as well as envisioned upgrades.
Suggestions have been made for a 80-100 km circumference Future Circular Collider (FCC) that coul... more Suggestions have been made for a 80-100 km circumference Future Circular Collider (FCC) that could ultimately contain a circular e+e- ring collider operating as a Higgs Factory as well as a 100 TeV hadron collider. Those suggestions have motivated us to propose an approach in which the project is sited at the location at the SSC tunnel, which has the lowest tunnel cost ever. The low tunnel cost would make it cost-effective to locate the 100 TeV Hadron Collider in a 270 km circumference tunne, using 4.5 Tesla superconducting magnets. The SSC tunnel itself would be used to house the Higgs Factory and the injector for the Hadron Collider. The injector for the Higgs Factory would be also used as a driver for an X-ray Free Electron Laser with unique capabilities for protein crystallography. The location of the project at a location with favorable geotechnology for minimum-cost tunneling, and low-cost/low-risk technology for the SRF and superconducting magnets, open the possibility to bui...
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