A quantity of considerable interest in studies of polarized light is the degree of polarization of a beam of radiation. Every transformation of Stokes parameters described by a Mueller matrix may change the degree of polarization. The nature of this change, however, is not so obvious (see, e.g., Ref. 1). The main purpose of this Letter is to present simple upper and lower bounds for the change ...

The Ni i 676.8 nm line is used by the Solar and Heliospheric Observatory Michelson Doppler Imager to measure the magnetic field and velocity field in the solar atmosphere. We make non-LTE calculations of this line in an atmosphere that is bombarded by an energetic electron beam. This case is associated with the occurrence of solar flares. The electron beam produces nonthermal ionization and exc...

The program of measurements at SLAC on superconduct. I ;r. ing niobium cavities is described. Results for TE and TM mode X-band cavities are presented. An RF magnetic breskdown field of 960 gauss and Q values greater than 1011 were measured for an electron beam welded TEOII mode cavity at ‘I 10.5 GHz. The best result for a TM mode cavity was a Q of 1.4 x log and a breakdown field of 360 gauss, ...

A common approach to the determination of the photoreflectance signal within the framework of wave optics is developed. It is shown that different modes of operation of the thermal wave photoreflectance microscope are possible. In recent years there has been increasing interest in the development and application of a photoreflectance thermal wave method. It has been successfully used as a power...

For J/ψ, ψ′, and τ masses measurement with the KEDR detector, the VEPP-4M collider is planned to operate at 1200–2000 MeV beam energies. Electron beam energy calibration with backscattered laser photons, performed at BESSY I storage ring [1], has shown the accuracy compatible with that obtained by resonant spin depolarization technique. We propose the non-head-on configuration of electron-laser...

We consider the process ee → χ̃+i χ̃−j at a linear collider with transverse e beam polarization. We investigate the influence of the CP phases on azimuthal asymmetries in ee → χ̃+i χ̃−j with subsequent two-body decays χ̃−j → ν̃ll− and χ̃−j → W−χ̃01. We show that triple product correlations involving the transverse e beam polarization vanish if at least one subsequent chargino decay is not observed. We ...

The image displacement instability (IDI) has been measured on the 20 MeV Axis I of the dual axis radiographic hydrodynamic test facility and compared to theory. A 0.23 kA electron beam was accelerated across 64 gaps in a low solenoid focusing field, and the position of the beam centroid was measured to 34.3 meters downstream from the cathode. One beam dynamics code was used to model the IDI fro...

This contribution will present the role of beam diagnostics in facing the challenges posed by running the LHC close to its design energy of 7TeV. Machine protection will be ever more critical, with the quench level of the magnets significantly reduced, so relying heavily on the beam loss system, abort gap monitor, interlocks on the beam position and fast beam current change system. Non-invasive...

background: physical wedges are still widely used as beam modifiers in external beam radiotherapy. however the presence of them in the beam trace may cause beam hardening which may not be considered in many treatment planning systems. the aim of this study is to investigate the beam hardening effect generated by physical wedges via different beam quality indexes as photon spectrum, half value l...

The photodissociation dynamics of bare I 2 and I 2 Ar at 413 and 390 nm have been investigated using a fast beam instrument coupled with a new photofragment coincidence imaging detector. Results from the application of this technique to the dissociation of I 2 and I 2 Ar yielded the dissociation energy of I 2 (D0ðI 2 Þ 1⁄4 1:012 0:008 eV) and I 2 –Ar binding energy (D0ðI 2 –ArÞ 1⁄4 45 8 meV). T...