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We present the design of a photon–photon collider based on conventional Compton gamma sources for the observation of secondary γ γ production. Two symmetric electron beams, generated by photocathodes and accelerated in linacs, produce two primary gamma rays through Compton back scattering with two high energy lasers. Tuning the system energy to the energy of the photon–photon cross section maximum, a flux of secondary gamma photons is generated. The process is analyzed by start-to-end simulations from the photocathodes to the propagation of the QED photons towards the detector. The new Monte Carlo code ‘Rate Of Scattering Events’ (ROSE) has been developed ad hoc for the counting of the QED events. Realistic numbers of the secondary gamma yield, referring to existing or approved set-ups and a discussion of the feasibility of the experiment are presented. [ABSTRACT FROM AUTHOR]

We present a new technique to calculate the cross section for diffractive vector meson production and deeply virtual Compton scattering (DVCS) in electron-ion collisions based on the dipole model. The measurement of these processes can provide valuable information on nonlinear QCD phenomena, such as gluon saturation, and is the the only known way to gain insight into the spatial distribution of gluons in nuclei. We present predictions of differential cross-section distribution dσ/dQ² and dσ/dt for J/ψ and φ meson production for diffractive processes of heavy nuclei, and demonstrate the feasibility of extracting the gluon source distribution of heavy nuclei, F(b), from coherent diffraction. We briefly introduce a new event generator based on our method that can be used for studying exclusive diffractive processes at a future electron-ion collider. [ABSTRACT FROM AUTHOR]

Abstract: An accurate knowledge of the colliding beam energies is essential for the current experiments with the KEDR detector at the VEPP-4M collider. Now the experimental activity is focused on the measurements of lepton mass and parameters of narrow resonances of the -family in the c.m.energy range of 3.0–4.0GeV. Two complementary approaches are used for the beam energy measurements. The resonant spin depolarization technique (RD) provides an accuracy about 1–3keV for the instantaneous beam energy value, but requires a special regime of the collider. Between calibrations the interpolation procedure is used providing the accuracy of 6–10keV for the and 15–30keV for the lepton mass determination experiments. Another approach allows to calculate beam energy via the maximum energy of backscattering laser photons. The Compton BackScattering (CBS) monitor allows continuous on-line monitoring of the beam energy with accuracy about 150keV, which is critical during the lepton mass measurement. The statistical error for a 1h period is about 100keV, the present systematic error is 50–70keV. [Copyright &y& Elsevier]

The CAIN simulation program was used to study the outgoing beam profile for the photon collider at ILC. The main aim of the analysis was to verify the feasibility of the photon linear collider running with 20 mrad electron beam crossing angle. The main problem is the distorted electron beam, which has to be removed from the interaction region. It is shown that with a new design of the final dipole, it should be possible to avoid large energy losses at the face of the magnet. [ABSTRACT FROM AUTHOR]

High energy photon colliders (γγ,γe) are based on e-e- linear colliders where high energy photons are produced using Compton scattering of laser light on high energy electrons just before the interaction point. This paper is a part of the Technical Design Report of the linear collider TESLA.1 Physics program, possible parameters and some technical aspects of the photon collider at TESLA are discussed. [ABSTRACT FROM AUTHOR]

A tightly focused laser beam (laser wire) is used for measurement of transverse electron beam sizes in storage rings and linear colliders. It is assumed that the laser beam does nothing with the electron beam except Compton scatterings which happen with a rather small probability. In reality, electrons crossing the laser beam get kicks (with 100% probability) proportional to the square of the laser field and inversely proportional to the beam energy. In practical cases of beam diagnostics this effect is negligible. [Copyright &y& Elsevier]

One of the interaction regions at the linear colliders should be compatible both with e+e- and γγ, γe modes of operation. In this paper, the differences in requirements and possible design solutions are discussed. [ABSTRACT FROM AUTHOR]