The technique of longitudinal momentum mining (LMM)[1] in the Fermilab Recycler was adopted in ea... more The technique of longitudinal momentum mining (LMM)[1] in the Fermilab Recycler was adopted in early 2005 to extract thirty-six equal intensity and equal 6Demittance antiproton bunches for proton-antiproton collider operation in the Tevatron. Since that time, several improvements have been made in the Recycler and the mining technique to handle higher intensity beams. Consequently, the Recycler has become a key contributor to the increased luminosity performance observed during Tevatron Run IIb. In this paper, we present an overview of the improvements and the current status of the momentum mining technique.
PACS2001. Proceedings of the 2001 Particle Accelerator Conference (Cat. No.01CH37268)
The Fermilab Main Injector was designed to accelerate protons and antiprotons from a momentum of ... more The Fermilab Main Injector was designed to accelerate protons and antiprotons from a momentum of 8.889 GeV/c to 150 GeV/c. In order to study antiproton deceleration, for the ultimate purpose of storing them in a Penning trap, the Main Injector was used to decelerate protons from the injection momentum down to the goal of 2.0 GeV/c. In this paper the operational experience of working with the Main Injector as a decelerator is presented.
The Recycler Ring at Fermilab is a storage ring with the aim to store and cool the precious antip... more The Recycler Ring at Fermilab is a storage ring with the aim to store and cool the precious antiprotons for the Tevatron collider program. It is built from permanent magnets to keep the antiprotons even in the case of a power failure. The initial orbit steering was done with a very limited set of powered correction elements. Eventually, all orbit correction will be done by realigning the gradient magnets and quadrupoles to obtain the desired closed orbit. We will present the orbit correction software and the procedure to realign the magnets. The first results of the orbit correction and the present status will be shown.
We report on the expression pattern of a novel EGF-containing gene named Maeg. RNA in situ studie... more We report on the expression pattern of a novel EGF-containing gene named Maeg. RNA in situ studies indicate that Maeg is ®rst activated during speci®cation of the early lateral dermatome, and continues to be expressed in all the dermatome derivatives as the dermis of the trunk, the hair follicles, and the mesenchyme of the cranio-facial region. q
PACS2001. Proceedings of the 2001 Particle Accelerator Conference (Cat. No.01CH37268), 2000
Abstract It is not unusual to place multiple accelerators in a common enclosure to save on civil ... more Abstract It is not unusual to place multiple accelerators in a common enclosure to save on civil construction costs. This often complicates operations, especially if accelerators are affecting each other. At Fermilab, the influence of a rapidly cycling Main Injector (MI) synchrotron ...
Proceedings of the 2003 Bipolar/BiCMOS Circuits and Technology Meeting (IEEE Cat. No.03CH37440), 2000
Injector and Recycler (antiproton accumulator) have been plagued by an emittance dilution of abou... more Injector and Recycler (antiproton accumulator) have been plagued by an emittance dilution of about a factor of 2 with corresponding beam loss. The source of the large dilution was traced to two Ti vacuum windows, one installed in each of the two transfer lines that connect the machines for beam injection/extraction. The dilution can be accounted for by calculating the increase in beam divergence due to multiple scattering in the windows followed by an amplitude mismatch that serves to further enhance the instantaneous dilution immediately downstream of the window. This work presents the analytical basis for the phase-space, or emittance, dilution due to the window, the subsequent optics mismatch, and then presents an analysis of beamline measurements that evidences the effect and validates the analytical argument. The data showed a strong skew quadrupole component in the transfer line optics that initially complicated the analysis, but was effectively eliminated in some of the data samples acquired under specific beam conditions.
Proceedings of the 2003 Bipolar/BiCMOS Circuits and Technology Meeting (IEEE Cat. No.03CH37440), 2003
The Recycler Ring, an 8 GeV antiproton accumulator, is being commissioned at Fermilab. Antiproton... more The Recycler Ring, an 8 GeV antiproton accumulator, is being commissioned at Fermilab. Antiproton transfers in and out of the Recycler Ring take place through two transfer lines connecting the Recycler to the Main Injector. Transfer line layout and operation of beam transfers will be described. Particular attention has been paid to injection mismatch effects, in order to limit emittance growth during transfers. A considerable improvement has been achieved by removing vacuum windows, previously present in both transfer lines.
Electron cooling of 8 GeV antiprotons at Fermilab's Recycler storage ring is now routinely us... more Electron cooling of 8 GeV antiprotons at Fermilab's Recycler storage ring is now routinely used in the collider operation. It requires a 0.1-0.5 A, 4.3 MeV dc electron beam and is designed to increase the longitudinal phase-space density of the circulating antiproton beam. This paper briefly describes the characteristics of the electron beam that were achieved to successfully cool antiprotons. Then, results from various cooling force measurements along with comparison to a non-magnetized model are presented. Finally, operational aspects of the implementation of electron cooling at the Recycler are discussed, such as adjustments to the cooling rate and the influence of the electron beam on the antiproton beam lifetime.
The Recycler ring is an 8 GeV permanent magnet storage ring where antiprotons are accumulated and... more The Recycler ring is an 8 GeV permanent magnet storage ring where antiprotons are accumulated and prepared for Fermilab's Tevatron Collider program. With the goal of maximizing the integrated luminosity delivered to the experiments, storing, cooling and extracting antiprotons with high efficiency has been pursued. Over the past two years, while the average accumulation rate doubled, the Recycler continued to operate at a constant level of performance thanks to changes made to the Recycler Electron Cooler (energy stability and regulation, electron beam optics), RF manipulations and operating procedures. In particular, we discuss the current accumulation cycle in which ~400×10 10 antiprotons are accumulated and extracted to the Tevatron every ~15 hours.
Proceedings of the 2005 Particle Accelerator Conference, 2005
A 4.3-MeV electron cooling system has been installed at Fermilab in the Recycler antiproton stora... more A 4.3-MeV electron cooling system has been installed at Fermilab in the Recycler antiproton storage ring and is currently being commissioned. The cooling system is designed to assist accumulation of 8.9-GeV/c antiprotons for the Tevatron collider operations. This paper reports on the progress of the electron beam commissioning effort as well as on detailed plans of demonstrating the cooling of antiprotons.
PACS2001. Proceedings of the 2001 Particle Accelerator Conference (Cat. No.01CH37268), 2001
We investigate processes contributing to emittance growth in the Fermilab Recycler Ring. In addit... more We investigate processes contributing to emittance growth in the Fermilab Recycler Ring. In addition to beamgas multiple scattering, we also examine other external factors such as Main Injector ramping affecting the emittance growth.
PACS2001. Proceedings of the 2001 Particle Accelerator Conference (Cat. No.01CH37268), 2001
We study the Fermilab Recyler Ring beam life time due to various physical processes associated wi... more We study the Fermilab Recyler Ring beam life time due to various physical processes associated with beamgas interactions. This includes single coloumb scattering, electronic excitations, nuclear and multiple scattering processes. We compare the measured life time with those obtained from theoretical estimations. The results indicate addtional processes are also contributing to the actual beam life time.
The Recycler Ring Gradient Magnets were designed with end shims which correct the field shape (ha... more The Recycler Ring Gradient Magnets were designed with end shims which correct the field shape (harmonic components up to 10-pole). A standard correction was employed at one end to correct the average properties. A variable correction was used at the other end to correct individual magnet variations during the fabrication process. An initial Recycler operation revealed that the quadrupole fields did not produce the desired tune. In part, this was due to the sextupole of the end-shim interacting with the curved orbit through the straight magnet. The standard end-shim was replaced on all regular cell gradient magnets. Details of these end corrections and the resulting successful modification of the lattice are described
The average strain state of Ge films grown on Si(111) by surfactant mediated epitaxy has been com... more The average strain state of Ge films grown on Si(111) by surfactant mediated epitaxy has been compared to the ordering of the interfacial misfit dislocation network. Surprisingly, a smaller degree of average lattice relaxation was found in films grown at higher temperature. On the other hand, these films exhibit a better ordered dislocation network. This effect energetically compensates the higher strain at higher growth temperature, leading to the conclusion that, apart from the formation of misfit dislocations, their ordering represents an important channel for lattice-strain energy relaxation.
The members of the T-box gene family share a highly conserved DNA binding domain named the T-doma... more The members of the T-box gene family share a highly conserved DNA binding domain named the T-domain, and important developmental functions. Here we report the cloning of chicken Tbr1 and of murine and chicken Tbr2 (orthologs of the Xenopus eomesodermin gene), the mapping of the murine Tbr2 to chromosome 9, and their pattern of expression during mouse and chick embryogenesis. Both Tbr 1 and 2 have a restricted and conserved domain of expression in the telencephalic pallium of the two species. Chick Tbr2 has a speci®c and dynamic expression in the gastrulating embryo. q
Electron cooling of 8 GeV antiprotons at Fermilab's Recycler storage ring is now routinely used i... more Electron cooling of 8 GeV antiprotons at Fermilab's Recycler storage ring is now routinely used in the collider operation. It requires a 0.1-0.5 A, 4.3 MeV DC electron beam to increase the longitudinal phase-space density of the circulating antiproton beam. This paper discusses the latest status of the electron cooler and its mode of operation within the context of Fermilab's accelerator complex. In addition, we will show preliminary results that demonstrate electron cooling of the transverse phasespace of the antiproton beam.
We have isolated a family of four vertebrate genes homologous to eyes absent (eya), a key regulat... more We have isolated a family of four vertebrate genes homologous to eyes absent (eya), a key regulator of ocular development in Drosophila. Here we present the detailed characterization of the EYA4 gene in human and mouse. EYA4 encodes a 640 amino acid protein containing a highly conserved C-terminal domain of 271 amino acids which in Drosophila eya is known to mediate developmentally important protein-protein interactions. Human EYA4 maps to 6q23 and mouse Eya4 maps to the predicted homology region near the centromere of chromosome 10. In the developing mouse embryo, Eya4 is expressed primarily in the craniofacial mesenchyme, the dermamyotome and the limb. On the basis of map position and expression pattern, EYA4 is a candidate for oculo-dento-digital (ODD) syndrome, but no EYA4 mutations were found in a panel of ODD patients.
The technique of longitudinal momentum mining (LMM)[1] in the Fermilab Recycler was adopted in ea... more The technique of longitudinal momentum mining (LMM)[1] in the Fermilab Recycler was adopted in early 2005 to extract thirty-six equal intensity and equal 6Demittance antiproton bunches for proton-antiproton collider operation in the Tevatron. Since that time, several improvements have been made in the Recycler and the mining technique to handle higher intensity beams. Consequently, the Recycler has become a key contributor to the increased luminosity performance observed during Tevatron Run IIb. In this paper, we present an overview of the improvements and the current status of the momentum mining technique.
PACS2001. Proceedings of the 2001 Particle Accelerator Conference (Cat. No.01CH37268)
The Fermilab Main Injector was designed to accelerate protons and antiprotons from a momentum of ... more The Fermilab Main Injector was designed to accelerate protons and antiprotons from a momentum of 8.889 GeV/c to 150 GeV/c. In order to study antiproton deceleration, for the ultimate purpose of storing them in a Penning trap, the Main Injector was used to decelerate protons from the injection momentum down to the goal of 2.0 GeV/c. In this paper the operational experience of working with the Main Injector as a decelerator is presented.
The Recycler Ring at Fermilab is a storage ring with the aim to store and cool the precious antip... more The Recycler Ring at Fermilab is a storage ring with the aim to store and cool the precious antiprotons for the Tevatron collider program. It is built from permanent magnets to keep the antiprotons even in the case of a power failure. The initial orbit steering was done with a very limited set of powered correction elements. Eventually, all orbit correction will be done by realigning the gradient magnets and quadrupoles to obtain the desired closed orbit. We will present the orbit correction software and the procedure to realign the magnets. The first results of the orbit correction and the present status will be shown.
We report on the expression pattern of a novel EGF-containing gene named Maeg. RNA in situ studie... more We report on the expression pattern of a novel EGF-containing gene named Maeg. RNA in situ studies indicate that Maeg is ®rst activated during speci®cation of the early lateral dermatome, and continues to be expressed in all the dermatome derivatives as the dermis of the trunk, the hair follicles, and the mesenchyme of the cranio-facial region. q
PACS2001. Proceedings of the 2001 Particle Accelerator Conference (Cat. No.01CH37268), 2000
Abstract It is not unusual to place multiple accelerators in a common enclosure to save on civil ... more Abstract It is not unusual to place multiple accelerators in a common enclosure to save on civil construction costs. This often complicates operations, especially if accelerators are affecting each other. At Fermilab, the influence of a rapidly cycling Main Injector (MI) synchrotron ...
Proceedings of the 2003 Bipolar/BiCMOS Circuits and Technology Meeting (IEEE Cat. No.03CH37440), 2000
Injector and Recycler (antiproton accumulator) have been plagued by an emittance dilution of abou... more Injector and Recycler (antiproton accumulator) have been plagued by an emittance dilution of about a factor of 2 with corresponding beam loss. The source of the large dilution was traced to two Ti vacuum windows, one installed in each of the two transfer lines that connect the machines for beam injection/extraction. The dilution can be accounted for by calculating the increase in beam divergence due to multiple scattering in the windows followed by an amplitude mismatch that serves to further enhance the instantaneous dilution immediately downstream of the window. This work presents the analytical basis for the phase-space, or emittance, dilution due to the window, the subsequent optics mismatch, and then presents an analysis of beamline measurements that evidences the effect and validates the analytical argument. The data showed a strong skew quadrupole component in the transfer line optics that initially complicated the analysis, but was effectively eliminated in some of the data samples acquired under specific beam conditions.
Proceedings of the 2003 Bipolar/BiCMOS Circuits and Technology Meeting (IEEE Cat. No.03CH37440), 2003
The Recycler Ring, an 8 GeV antiproton accumulator, is being commissioned at Fermilab. Antiproton... more The Recycler Ring, an 8 GeV antiproton accumulator, is being commissioned at Fermilab. Antiproton transfers in and out of the Recycler Ring take place through two transfer lines connecting the Recycler to the Main Injector. Transfer line layout and operation of beam transfers will be described. Particular attention has been paid to injection mismatch effects, in order to limit emittance growth during transfers. A considerable improvement has been achieved by removing vacuum windows, previously present in both transfer lines.
Electron cooling of 8 GeV antiprotons at Fermilab's Recycler storage ring is now routinely us... more Electron cooling of 8 GeV antiprotons at Fermilab's Recycler storage ring is now routinely used in the collider operation. It requires a 0.1-0.5 A, 4.3 MeV dc electron beam and is designed to increase the longitudinal phase-space density of the circulating antiproton beam. This paper briefly describes the characteristics of the electron beam that were achieved to successfully cool antiprotons. Then, results from various cooling force measurements along with comparison to a non-magnetized model are presented. Finally, operational aspects of the implementation of electron cooling at the Recycler are discussed, such as adjustments to the cooling rate and the influence of the electron beam on the antiproton beam lifetime.
The Recycler ring is an 8 GeV permanent magnet storage ring where antiprotons are accumulated and... more The Recycler ring is an 8 GeV permanent magnet storage ring where antiprotons are accumulated and prepared for Fermilab's Tevatron Collider program. With the goal of maximizing the integrated luminosity delivered to the experiments, storing, cooling and extracting antiprotons with high efficiency has been pursued. Over the past two years, while the average accumulation rate doubled, the Recycler continued to operate at a constant level of performance thanks to changes made to the Recycler Electron Cooler (energy stability and regulation, electron beam optics), RF manipulations and operating procedures. In particular, we discuss the current accumulation cycle in which ~400×10 10 antiprotons are accumulated and extracted to the Tevatron every ~15 hours.
Proceedings of the 2005 Particle Accelerator Conference, 2005
A 4.3-MeV electron cooling system has been installed at Fermilab in the Recycler antiproton stora... more A 4.3-MeV electron cooling system has been installed at Fermilab in the Recycler antiproton storage ring and is currently being commissioned. The cooling system is designed to assist accumulation of 8.9-GeV/c antiprotons for the Tevatron collider operations. This paper reports on the progress of the electron beam commissioning effort as well as on detailed plans of demonstrating the cooling of antiprotons.
PACS2001. Proceedings of the 2001 Particle Accelerator Conference (Cat. No.01CH37268), 2001
We investigate processes contributing to emittance growth in the Fermilab Recycler Ring. In addit... more We investigate processes contributing to emittance growth in the Fermilab Recycler Ring. In addition to beamgas multiple scattering, we also examine other external factors such as Main Injector ramping affecting the emittance growth.
PACS2001. Proceedings of the 2001 Particle Accelerator Conference (Cat. No.01CH37268), 2001
We study the Fermilab Recyler Ring beam life time due to various physical processes associated wi... more We study the Fermilab Recyler Ring beam life time due to various physical processes associated with beamgas interactions. This includes single coloumb scattering, electronic excitations, nuclear and multiple scattering processes. We compare the measured life time with those obtained from theoretical estimations. The results indicate addtional processes are also contributing to the actual beam life time.
The Recycler Ring Gradient Magnets were designed with end shims which correct the field shape (ha... more The Recycler Ring Gradient Magnets were designed with end shims which correct the field shape (harmonic components up to 10-pole). A standard correction was employed at one end to correct the average properties. A variable correction was used at the other end to correct individual magnet variations during the fabrication process. An initial Recycler operation revealed that the quadrupole fields did not produce the desired tune. In part, this was due to the sextupole of the end-shim interacting with the curved orbit through the straight magnet. The standard end-shim was replaced on all regular cell gradient magnets. Details of these end corrections and the resulting successful modification of the lattice are described
The average strain state of Ge films grown on Si(111) by surfactant mediated epitaxy has been com... more The average strain state of Ge films grown on Si(111) by surfactant mediated epitaxy has been compared to the ordering of the interfacial misfit dislocation network. Surprisingly, a smaller degree of average lattice relaxation was found in films grown at higher temperature. On the other hand, these films exhibit a better ordered dislocation network. This effect energetically compensates the higher strain at higher growth temperature, leading to the conclusion that, apart from the formation of misfit dislocations, their ordering represents an important channel for lattice-strain energy relaxation.
The members of the T-box gene family share a highly conserved DNA binding domain named the T-doma... more The members of the T-box gene family share a highly conserved DNA binding domain named the T-domain, and important developmental functions. Here we report the cloning of chicken Tbr1 and of murine and chicken Tbr2 (orthologs of the Xenopus eomesodermin gene), the mapping of the murine Tbr2 to chromosome 9, and their pattern of expression during mouse and chick embryogenesis. Both Tbr 1 and 2 have a restricted and conserved domain of expression in the telencephalic pallium of the two species. Chick Tbr2 has a speci®c and dynamic expression in the gastrulating embryo. q
Electron cooling of 8 GeV antiprotons at Fermilab's Recycler storage ring is now routinely used i... more Electron cooling of 8 GeV antiprotons at Fermilab's Recycler storage ring is now routinely used in the collider operation. It requires a 0.1-0.5 A, 4.3 MeV DC electron beam to increase the longitudinal phase-space density of the circulating antiproton beam. This paper discusses the latest status of the electron cooler and its mode of operation within the context of Fermilab's accelerator complex. In addition, we will show preliminary results that demonstrate electron cooling of the transverse phasespace of the antiproton beam.
We have isolated a family of four vertebrate genes homologous to eyes absent (eya), a key regulat... more We have isolated a family of four vertebrate genes homologous to eyes absent (eya), a key regulator of ocular development in Drosophila. Here we present the detailed characterization of the EYA4 gene in human and mouse. EYA4 encodes a 640 amino acid protein containing a highly conserved C-terminal domain of 271 amino acids which in Drosophila eya is known to mediate developmentally important protein-protein interactions. Human EYA4 maps to 6q23 and mouse Eya4 maps to the predicted homology region near the centromere of chromosome 10. In the developing mouse embryo, Eya4 is expressed primarily in the craniofacial mesenchyme, the dermamyotome and the limb. On the basis of map position and expression pattern, EYA4 is a candidate for oculo-dento-digital (ODD) syndrome, but no EYA4 mutations were found in a panel of ODD patients.
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Papers by C. Gattuso