Accelerator designs intended to provide acceleration at a much lower cost per Joule than the ILSE... more Accelerator designs intended to provide acceleration at a much lower cost per Joule than the ILSE or ELISE designs are under study. For these designs, which typically have many beams, an injector of significantly lower cost is needed. A goal, which from our design appears to be achievable, is to reduce the transverse dimension to half that of the 2 MeV, 800 mA ILSE injector(E. Henestroza, ``Injectors for Heavy Ion Fusion", Proc. of the 11th International Wkshp. on Laser Interaction and Related Plasma Phenomena, 1993.) while generating about the same current. A single channel of a lower cost injector includes an 800 kV column, accelerating a 700 mA beam extracted from a potassium source of 4 cm radius by a 120 kV electrode. The beam passes into a superconducting 7 T solenoid of 15 cm aperture and 15 cm length. This high-field solenoid provides the focusing needed for a small beam without increasing the electric field gradient. The injector and its matching section, also designed...
Information on the current limit in a long quadrupole transport channel is required in designing ... more Information on the current limit in a long quadrupole transport channel is required in designing an accelerator driver for an inertial confinement fusion system. Although a current transport limit was proposed by Maschke, quantitative estimates require a detailed knowledge of the stability of the beam. Analytic calculations based on the Kapchinskij-Vladimirskij (K-V) distribution function have identified transversely unstable modes, but particle simulations have shown that some of the K-V instabilities are benign, i.e., particles redistribute themselves in the 4-D transverse phase space, but the rms emittances do not grow. Some preliminary results of beam transport experiments were reported in the 1983 Particle Accelerator Conference in Santa Fe.
The cost of induction linac accelerators for inertial fusion using mass 200 ions at a charge stat... more The cost of induction linac accelerators for inertial fusion using mass 200 ions at a charge state of +3 for target yields of 300, 600, and 1200 MJ is presented. The ions are injected into the accelerator at 3 MV, and accelerated to the required voltage appropriate to the desired target yield. A cost comparison of the low voltage portion
Proceedings of the 1997 Particle Accelerator Conference (Cat. No.97CH36167), 2000
Transverse beam combining is a cost-saving option employed in many designs for induction linac he... more Transverse beam combining is a cost-saving option employed in many designs for induction linac heavy ion fusion drivers. The resultant transverse emittance increase, due predominantly to anharmonic space charge forces, must be kept minimal so that the beam remains focusable at the target. A prototype combining experiment has been built and preliminary results are presented. Four sources each produce up to 4.8 mA Cs + beams at 160 keV. Focusing upstream of the merge consists of four quadrupoles and a final combined-function element (quadrupole & dipole). All lattice elements of the prototype are electrostatic. Due to the small distance between beams near the merge (~ 3-4 mm), the electrodes here are a cage of small rods, each at different voltage.
Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366), 1999
In a typical heavy ion fusion driver design, the induction linac requires a multiple beam injecto... more In a typical heavy ion fusion driver design, the induction linac requires a multiple beam injector. We present a conceptual design for an 84-beam injector system with each beam channel carrying 0.5 A of beam current. Each channel starts with a 10-cm diameter surface ionization source followed by a 1.7 MV electrostatic Einzel lens-type preaccelerator and an electrostatic quadrupole (ESQ) matching section. The preaccelerator and matching section are 0.7 m and 5.0 m long respectively. The array has an overall diameter of 3.0 m at the ion source end and 1.0 m diameter at the exit.
Vacuum ballistic focusing is a straightforward method to achieve the heavy ion beam spot size nec... more Vacuum ballistic focusing is a straightforward method to achieve the heavy ion beam spot size necessary for an inertial confinement fusion target. Proper scaling of particle energy, mass, beam current, beam emittance, and magnetic field replicates the dynamics of a full driver beam in a small laboratory beam. In this one-tenth scale experiment, both 120 keV K^+ and Cs^+ ions
We present a conceptual design of a superconducting quadrupole magnet array for the side-by-side ... more We present a conceptual design of a superconducting quadrupole magnet array for the side-by-side transport of multiple high current particle beams in induction linear accelerators. The magnetic design uses a modified cosine 2θ current distribution inside a square cell boundary. Each interior magnet's neighbors serve as the return flux paths and the poles are placed as close as possible to
A source-to-target modet for a induction linac driver for heavy ion &ion has been developed and i... more A source-to-target modet for a induction linac driver for heavy ion &ion has been developed and is described here. Design features for a reference case driver that meets the requirements of one current target design are gtven, and the systems analyses supporting the point design are dkussed. Directions for fbture work are noted.
Proceedings of the 2005 Particle Accelerator Conference, 2005
A design for a high gradient, low inductance pulsed quadrupole magnet is presented. The magnet is... more A design for a high gradient, low inductance pulsed quadrupole magnet is presented. The magnet is a circular current dominated design with a circular iron return yoke. Conductor angles are determined by a method of direct multipole elimination which theoretically eliminates the first four higher order multipole field components. Coils are fabricated from solid round film-insulated conductor, wound as a single layer “non-spiral bedstead” coil having a diagonal leadout entirely within one upturned end. The coils are wound and stretched straight in a special winder, then bent in simple fixtures to form the upturned ends.
Conference Record of the 1991 IEEE Particle Accelerator Conference, 1991
An injector is being developed at LBL that would serve as the front end of a scaled induction lin... more An injector is being developed at LBL that would serve as the front end of a scaled induction linac accelerator technology experiment for heavy ion fusion. The ion mass being used is in the range 10-18. It is a multi-beam device intended to accelerate up to 2 Me V with 500 mA in each beam. The first half of the accelerating column has been built and experiments with one carbon beam are underway at the 1 Me V level.
This study group was initiated to consider whether there were any "show-stopper" issues with acce... more This study group was initiated to consider whether there were any "show-stopper" issues with accelerators for heavy-ion warm-dense matter (WDM) and heavy-ion inertial fusion energy (HIF), and to prioritize them. Showstopper issues appear to be categorized as limits to beam current; that is, the beam is expected to be well-behaved below the current limit, and significantly degraded in current or emittance if the current limit is exceeded at some region of an accelerator. We identified 14 issues: 1-6 could be addressed in the near term, 7-10 may provide attractive solutions to performance and cost issues, 11-12 address multibeam effects that cannot be more than partially studied in near-term facilities, and 13-14 address new issues that are present in some novel driver concepts. Comparing the issues with the new experimental, simulation, and theoretical tools that we have developed, it is apparent that our new capabilities provide an opportunity to reexamine and significantly increase our understanding of the number one issue-halo growth and mitigation.
A simple theoretical study and numerical estimate is presented for the transverse amplitude growt... more A simple theoretical study and numerical estimate is presented for the transverse amplitude growth of a nonrelativistic heavy ion beam in an induction linac, as envisaged for use in commercial power plants, due to the nonregenerative coherent beam breakup mode. An equivalent electrical circuit has been used to represent the accelerating induction modules. Our calculation shows that for the parameters of interest, the beam breakup amplitude for a heavy ion beam grows extremely slowly in the time scales of interest, to magnitudes insignificant for transport purposes. It is concluded that the coherent beam breakup mode does not pose any serious threat to the stability of a high current (kA) heavy ion beam in an induction linac.
This is a Library Circulating Copy which ma~ be borrowed for two weeks. For a personal retention ... more This is a Library Circulating Copy which ma~ be borrowed for two weeks. For a personal retention copy, call T ech.lnJo. Diuision, Ext.
Accelerator designs intended to provide acceleration at a much lower cost per Joule than the ILSE... more Accelerator designs intended to provide acceleration at a much lower cost per Joule than the ILSE or ELISE designs are under study. For these designs, which typically have many beams, an injector of significantly lower cost is needed. A goal, which from our design appears to be achievable, is to reduce the transverse dimension to half that of the 2 MeV, 800 mA ILSE injector(E. Henestroza, ``Injectors for Heavy Ion Fusion", Proc. of the 11th International Wkshp. on Laser Interaction and Related Plasma Phenomena, 1993.) while generating about the same current. A single channel of a lower cost injector includes an 800 kV column, accelerating a 700 mA beam extracted from a potassium source of 4 cm radius by a 120 kV electrode. The beam passes into a superconducting 7 T solenoid of 15 cm aperture and 15 cm length. This high-field solenoid provides the focusing needed for a small beam without increasing the electric field gradient. The injector and its matching section, also designed...
Information on the current limit in a long quadrupole transport channel is required in designing ... more Information on the current limit in a long quadrupole transport channel is required in designing an accelerator driver for an inertial confinement fusion system. Although a current transport limit was proposed by Maschke, quantitative estimates require a detailed knowledge of the stability of the beam. Analytic calculations based on the Kapchinskij-Vladimirskij (K-V) distribution function have identified transversely unstable modes, but particle simulations have shown that some of the K-V instabilities are benign, i.e., particles redistribute themselves in the 4-D transverse phase space, but the rms emittances do not grow. Some preliminary results of beam transport experiments were reported in the 1983 Particle Accelerator Conference in Santa Fe.
The cost of induction linac accelerators for inertial fusion using mass 200 ions at a charge stat... more The cost of induction linac accelerators for inertial fusion using mass 200 ions at a charge state of +3 for target yields of 300, 600, and 1200 MJ is presented. The ions are injected into the accelerator at 3 MV, and accelerated to the required voltage appropriate to the desired target yield. A cost comparison of the low voltage portion
Proceedings of the 1997 Particle Accelerator Conference (Cat. No.97CH36167), 2000
Transverse beam combining is a cost-saving option employed in many designs for induction linac he... more Transverse beam combining is a cost-saving option employed in many designs for induction linac heavy ion fusion drivers. The resultant transverse emittance increase, due predominantly to anharmonic space charge forces, must be kept minimal so that the beam remains focusable at the target. A prototype combining experiment has been built and preliminary results are presented. Four sources each produce up to 4.8 mA Cs + beams at 160 keV. Focusing upstream of the merge consists of four quadrupoles and a final combined-function element (quadrupole & dipole). All lattice elements of the prototype are electrostatic. Due to the small distance between beams near the merge (~ 3-4 mm), the electrodes here are a cage of small rods, each at different voltage.
Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366), 1999
In a typical heavy ion fusion driver design, the induction linac requires a multiple beam injecto... more In a typical heavy ion fusion driver design, the induction linac requires a multiple beam injector. We present a conceptual design for an 84-beam injector system with each beam channel carrying 0.5 A of beam current. Each channel starts with a 10-cm diameter surface ionization source followed by a 1.7 MV electrostatic Einzel lens-type preaccelerator and an electrostatic quadrupole (ESQ) matching section. The preaccelerator and matching section are 0.7 m and 5.0 m long respectively. The array has an overall diameter of 3.0 m at the ion source end and 1.0 m diameter at the exit.
Vacuum ballistic focusing is a straightforward method to achieve the heavy ion beam spot size nec... more Vacuum ballistic focusing is a straightforward method to achieve the heavy ion beam spot size necessary for an inertial confinement fusion target. Proper scaling of particle energy, mass, beam current, beam emittance, and magnetic field replicates the dynamics of a full driver beam in a small laboratory beam. In this one-tenth scale experiment, both 120 keV K^+ and Cs^+ ions
We present a conceptual design of a superconducting quadrupole magnet array for the side-by-side ... more We present a conceptual design of a superconducting quadrupole magnet array for the side-by-side transport of multiple high current particle beams in induction linear accelerators. The magnetic design uses a modified cosine 2θ current distribution inside a square cell boundary. Each interior magnet's neighbors serve as the return flux paths and the poles are placed as close as possible to
A source-to-target modet for a induction linac driver for heavy ion &ion has been developed and i... more A source-to-target modet for a induction linac driver for heavy ion &ion has been developed and is described here. Design features for a reference case driver that meets the requirements of one current target design are gtven, and the systems analyses supporting the point design are dkussed. Directions for fbture work are noted.
Proceedings of the 2005 Particle Accelerator Conference, 2005
A design for a high gradient, low inductance pulsed quadrupole magnet is presented. The magnet is... more A design for a high gradient, low inductance pulsed quadrupole magnet is presented. The magnet is a circular current dominated design with a circular iron return yoke. Conductor angles are determined by a method of direct multipole elimination which theoretically eliminates the first four higher order multipole field components. Coils are fabricated from solid round film-insulated conductor, wound as a single layer “non-spiral bedstead” coil having a diagonal leadout entirely within one upturned end. The coils are wound and stretched straight in a special winder, then bent in simple fixtures to form the upturned ends.
Conference Record of the 1991 IEEE Particle Accelerator Conference, 1991
An injector is being developed at LBL that would serve as the front end of a scaled induction lin... more An injector is being developed at LBL that would serve as the front end of a scaled induction linac accelerator technology experiment for heavy ion fusion. The ion mass being used is in the range 10-18. It is a multi-beam device intended to accelerate up to 2 Me V with 500 mA in each beam. The first half of the accelerating column has been built and experiments with one carbon beam are underway at the 1 Me V level.
This study group was initiated to consider whether there were any "show-stopper" issues with acce... more This study group was initiated to consider whether there were any "show-stopper" issues with accelerators for heavy-ion warm-dense matter (WDM) and heavy-ion inertial fusion energy (HIF), and to prioritize them. Showstopper issues appear to be categorized as limits to beam current; that is, the beam is expected to be well-behaved below the current limit, and significantly degraded in current or emittance if the current limit is exceeded at some region of an accelerator. We identified 14 issues: 1-6 could be addressed in the near term, 7-10 may provide attractive solutions to performance and cost issues, 11-12 address multibeam effects that cannot be more than partially studied in near-term facilities, and 13-14 address new issues that are present in some novel driver concepts. Comparing the issues with the new experimental, simulation, and theoretical tools that we have developed, it is apparent that our new capabilities provide an opportunity to reexamine and significantly increase our understanding of the number one issue-halo growth and mitigation.
A simple theoretical study and numerical estimate is presented for the transverse amplitude growt... more A simple theoretical study and numerical estimate is presented for the transverse amplitude growth of a nonrelativistic heavy ion beam in an induction linac, as envisaged for use in commercial power plants, due to the nonregenerative coherent beam breakup mode. An equivalent electrical circuit has been used to represent the accelerating induction modules. Our calculation shows that for the parameters of interest, the beam breakup amplitude for a heavy ion beam grows extremely slowly in the time scales of interest, to magnitudes insignificant for transport purposes. It is concluded that the coherent beam breakup mode does not pose any serious threat to the stability of a high current (kA) heavy ion beam in an induction linac.
This is a Library Circulating Copy which ma~ be borrowed for two weeks. For a personal retention ... more This is a Library Circulating Copy which ma~ be borrowed for two weeks. For a personal retention copy, call T ech.lnJo. Diuision, Ext.
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