High luminosity interaction region design for collisions with detector solenoid

An innovatory interaction region has been recently conceived and realized on the Frascati DA{\Phi}NE lepton collider. The concept of tight focusing and small crossing angle adopted until now to achieve high luminosity in multibunch collisions has evolved towards enhanced beam focusing at the interaction point with large horizontal crossing angle, thanks to a new compensation mechanism for the beam-beam resonances. The novel configuration has been tested with a small detector without solenoidal field yielding a remarkable improvement in terms of peak as well as integrated luminosity. The high luminosity interaction region has now been modified to host a large detector with a strong solenoidal field which significantly perturbs the beam optics introducing new design challenges in terms of interaction region optics design, beam transverse coupling control and beam stay clear requirementsComment: 3 pages, 4 figures, presented to the IPAC10 conferenc

Crab Waist Scheme Luminosity and Background Diagnostic at DAFNE

TUPTPF029International audienceTest of the crab waist scheme, undergoing at the Frascati DAFNE accelerator complex, needs a fast and accurate measurement of the luminosity, as well as a full characterization of the background conditions. Three different monitors, a Bhabha calorimeter, a Bhabha GEM tracker and a gamma bremsstrahlung proportional counter have been designed, tested and installed on the accelerator at the end of January 2008. Results from beam-test measurements, comparison with the Monte Carlo simulation and preliminary data collected during the SIDDHARTA run are presented

Sector DC Dipoles Design for the Beam Test Facility Upgrade

The Beam Test Facility (BTF) is part of the DAΦNE accelerators system of INFN Frascati National Laboratory (LNF). It is a transfer-line optimized for selection, attenuation and manipulation of electrons and positrons extracted from the DAΦNE LINAC. An upgrade of the line is scheduled by the end of 2018 in order to reach a beam energy of 920 MeV (compared to the actual 750 MeV), and adding a new branch to the present transfer line, in order to use two different beam lines. The layout of the new lines foresees seven new quadrupoles, one fast ramped dipole, two H-shape sector dipoles, and finally a C-shape sector dipole. In this paper, the magnets requirements, all the magnetic design aspects of the two H-shape and of the C-shape sector dipoles shall be presented, including the Finite Elements Analysis (F.E.A.), the sizing of the water-cooling and an overview of the status of the manufacturing

Detectors for absolute luminosity measurement at DAFNE

Dedicated to the memory of Pietro Tiseo, INFN LNF.International audienceSince the second half of year 2007, the Frascati Φ-factory DAFNE has been running with an upgraded interaction region in order to test the crabbed waist collision scheme. The aim is to reach a large improvement of the specific luminosity of the accelerator. We describe the various detectors realized to have a reliable and fast absolute luminosity measurement, the on-line analysis in order to get rid of the machine background contribution, and the performances of the system

Description and performances of luminosity and background detectors at the upgraded e+e− DAΦNE collider

Testing the new crab waist collision scheme at the e+e− Frascati DAΦNE accelerator complex requires a fast and accurate measurement of the absolute luminosity, as well as a full characterization of the background conditions. To fulfill these requirements, dedicated detectors have been built by the LUMI Collaboration and operated during the 2008 and 2009 DAΦNE runs, providing valuable inputs for the accelerator team. This article motivates their design, describes their installation in the modified interaction region and presents their performances. Another article in the same issue focuses on the results achieved using these detectors

Luminosity and background measurements at the e^+e^− DAΦNE collider upgraded with the crab waist scheme

The crab waist collision scheme has been successfully tested at the e+e− Frascati collider during the 2008–2009 runs: the gain in luminosity is consistent with the predictions while the background remains sustainable. Among the various inputs used by the DAΦNE accelerator team to steer this new machine and improve its performances, key online information, absolute luminosity and background level measurements, has been provided by the LUMI detectors: a Bhabha calorimeter and two gamma bremsstrahlung proportional counters. This paper focuses on the results achieved with this experimental setup, described in details in another article