Engineering topics

Alesini, D

Publications and source records attributed to Alesini, D.

8 records

DOE OSTI2012

High-Power Comparison Among Brazed, Clamped and Electroformed X-Band Cavities

We report the building procedure of X-band copper structures using the electroforming and electroplating techniques. These techniques allow the deposition of copper layers on a suitable die and they can be used to build RF structures avoiding the high temperature brazing step in the standard technique. We show the constructed prototypes and low power RF measurements and discuss the results of the high power tests at SLAC National Accelerator Laboratory.

43 PARTICLE ACCELERATORS↗

DOE OSTI2012

Technological Issues and High Gradient Test Results on X-Band Molybdenum Accelerating Structures

Two 11.424 GHz single cell standing wave accelerating structures have been fabricated for high gradient RF breakdown studies. Both are brazed structures: one made from copper and the other from sintered molybdenum bulk. The tests results are presented and compared to those of similar devices constructed at SLAC (Stanford Linear Accelerator Center) and KEK (Ko Enerugi Kasokuki Kenkyu Kiko). The technological issues to build both sections are discussed.

43 PARTICLE ACCELERATORS↗

DOE OSTI2012

Results From the DAFNE High Luminosity Test

The DAPHNE collider, based on a new collision scheme including Large Piwinsky angle and Crab-Waist, has been successfully commissioned and is presently delivering luminosity to the SIDDHARTA detector. Large crossing angle and Crab-Waist scheme proved to be effective in: (1) Increasing luminosity, now a factor 2.7 higher than in the past; and (2) controlling transverse beam blow-up due to the beam-beam. Work is in progress to reach the ultimate design luminosity goal 5.0 {center_dot} 10{sup 32} cm{sup -2}s{sup -1}. The new collision scheme is the main design concept for a new project aimed at building a Super-B factory that is expected to achieve a luminosity of the order of 10{sup 36} cm{sup -2} s{sup -1} and it has been also taken into account to upgrade one of the LHC interaction regions.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2011

Crab Waist Collision at DAFNE

DAFNE is an accelerator complex consisting of a double ring lepton collider working at the c.m. energy of the {Phi}-resonance (1.02 GeV) and an injection system. In its original configuration the collider consisted of two independent rings, each {approx}97 m long, sharing two 10 m long interaction regions (IR1 and IR2) where the KLOE and FINUDA or DEAR detectors were respectively installed. A full energy injection system, including an S-band linac, 180 m long transfer lines and an accumulator/damping ring, provides fast and high efficiency electron positron injection also in topping-up mode during collisions. Recently the DAFNE collider has been upgraded in order to implement a new collision scheme based on large Piwinski angle and cancellation of the synchro-betatron resonances by means of electromagnetic sextupoles (Crab-Waist compensation). The novel approach has proved to be effective in improving beam-beam interaction and collider luminosity.

43 PARTICLE ACCELERATORS↗

DOE OSTI2011

DAFNE Status Report

DAFNE, the Frascati {Phi}-factory, is providing an increasing peak and integrated luminosity for the KLOE experiment. Such improvements, together with a background reduction in the KLOE detector, have been obtained after continuous machine studies. An increase of the single bunch luminosity has been achieved essentially by the reduction of the effects of machine non-linearities. The integrated luminosity was improved by the capability of topping up the beam currents while keeping the KLOE detector on, together with an increase of the stored currents.

43 PARTICLE ACCELERATORS↗

DOE OSTI2011

Crabbed Waist Collisions in DAFNE and Super-B Design

The new idea of increasing the luminosity of a collider with crab waist collisions and first experimental results from the DA{Phi}NE {Phi}-Factory at LNF, Frascati, using this concept are presented. Consequences for the design of future factories will be discussed. An outlook to the performance reach with crab waist collisions is given, with emphasis on future B Factories.

43 PARTICLE ACCELERATORS↗

DOE OSTI2011

DAFNE Setup And Operation With the Crab-Waist Collision Scheme

In the second half of 2007 a major upgrade has been implemented on the Frascati DA{Phi}NE collider in order to test the novel idea of Crab-Waist collisions. New vacuum chambers and permanent quadrupole magnets have been designed, built and installed to realize the new configuration. At the same time the performances of relevant hardware components, such as fast injection kickers and shielded bellows have been improved relying on new design concepts. The collider has been successfully commissioned in this new configuration. The paper describes several experimental results about linear and non-linear optics setup and optimization, damping of beam-beam instabilities and discusses the obtained luminosity performances. DA{Phi}NE [1] is the Frascati lepton collider working at the c m. energy of the {Phi} meson resonance (1020). It came in operation in 2001 and till summer 2007 provided luminosity, in sequence, to three different experiments which logged a total integrated luminosity of {approx} 4.4 fb{sup -1}. During these years the collider reached its best performances in terms of luminosity and background (L{sub peak} = 1.6 x 10{sup 32} cm{sup -2}s{sup -1} L{sub day} {approx} 10 pb{sup -1}) by means of several successive upgrades, relying on the experience gathered during the collider operations and implemented exploiting the shutdowns required for the experiment change over [2, 3, 4].

43 PARTICLE ACCELERATORS↗

DOE OSTI2011

The Super-B Project Accelerator Status

The SuperB project is an international effort aiming at building in Italy a very high luminosity e{sup +}e{sup -} (10{sup 36} cm{sup -2} sec{sup -1}) asymmetric collider at the Y(4S) energy in the CM. The accelerator design has been extensively studied and changed during the past year. The present design, based on the new collision scheme, with large Piwinski angle and the use of 'crab waist' sextupoles already successfully tested at the DA{Phi}NE {Phi}-Factory at LNF Frascati, provides larger flexibility, better dynamic aperture and spin manipulation sections in the Low Energy Ring (LER) for longitudinal polarization of the electron beam at the Interaction Point (IP). The Interaction Region (IR) has been further optimized in terms of apertures and reduced backgrounds in the detector. The injector complex design has been also updated. A summary of the project status will be presented in this paper. The SuperB collider can reach a peak luminosity of 10{sup 36} cm{sup -2} sec{sup -1} with beam currents and bunch lengths similar to those of the past and present e{sup +}e{sup -} Factories, through the use of smaller emittances and new scheme of crossing angle collision. The beams are stored in two rings at 6.7 GeV (HER) and 4.2 GeV (LER). Unique features of the project are the polarization of the electron beam in the LER and the possibility to decrease the energies for running at the {tau}/charm threshold. The option to reuse the PEP-II B-Factory (SLAC) hardware will allow reducing costs. The SuperB facility will require a big complex of civil infrastructure. The main construction, which will house the final part of the LINAC, the injection lines, the damping rings, and the storage rings, will be mainly underground. Two sites have been considered: the campus of Tor Vergata University near Frascati, and the INFN Frascati Laboratory. No decision has been made yet. A footprint of the possible SuperB layout on the LNF area is shown in Fig. 1.

43 PARTICLE ACCELERATORS↗