The system for delivery of IR laser radiaton into high vacuum

Abstract

The system for insertion of a laser beam into the vacuum chamber of high-energy storage ring is described. The main part of the system is the high-vacuum viewport for the IR radiation, based on ZnSe or GaAs crystals. The design of the viewports is presented.

Observation of a fine structure in e+e− → hadrons production at the nucleon-antinucleon threshold

“…energy spread. The beam energy and energy spread have been monitored by the back-scattering-laser-light system [23,24], providing an absolute energy measurement with better than 0.1 MeV uncertainty in every single measurement. During data taking the E c.m.…”

Study of the process e+e− → K+K−η with the CMD-3 detector at the VEPP-2000 collider

“…The integrated luminosity at each energy point was deter-mined using events of the processes e + e − →e + e − and e + e − →2γ [17]. The beam energy was monitored by measuring the current in the dipole magnets of the main ring (in 2011 and 2012), and by using the Back-Scattering-Laser-Light system (in 2017) [18,19]. In the runs of 2011 and 2012 we use the measured average momentum of electrons and positrons in events of Bhabha scattering, as well as the average momentum of proton-antiproton pairs from the process e + e − →pp process [20] to determine the actual E c.m.…”

Measurement of hadronic cross-sections at VEPP-2000

“…During the 2012 season the beam energy monitoring system [8,9] has been installed and commissioned. The system allows to continuously monitor beam energy concurrently with data taking with relative precision < 10 −4 using Compton backscattering of laser photons at the electron beam.…”