A method of testing of threshold SiO2 aerogel Cherenkov detectors using cosmic radiation is described. The method requires a minimum amount of additional electronics and does not involve massive absorber layers (e.g., lead). The method makes it possible to directly take into account the threshold in determining the efficiency of the detectors under study and to test their operation in different energy ranges for relativistic charged particles. Good agreement between the results of the simulation and measurements was obtained.

A variant of testing threshold SiO2 aerogel Cherenkov detectors using cosmic radiation is described. The implementation requires a minimum amount of additional electronics and does not involve massive absorber layers (lead, etc.). The method makes it possible to accurately determine efficiency of detectors under study and to study operation of detectors in different energy ranges for relativistic particles.

A method for testing threshold SiO2-aerogel Cherenkov detectors using cosmic radiation is described. The implementation requires a minimal amount of additional electronics and does not involve massive absorber layers (such as lead, etc.). The method allows for accurate determination of the efficiency of the investigated detectors and for the study of the detectors' operation in different energy intervals for relativistic particles.

Photonuclear methods used earlier in experiments at electron accelerators have been adapted for femtosecond pulsed lasers. In particular, the problem of measuring wide electron spectra under conditions of a high counting rate and, hence, a high probability of pulse pileup has been solved. To provide long-term stability of electron beams from plasma, a magnetic spectrometer combined with a magnetic-induction sensor has been developed. This spectrometer is capable of measuring the electron-beam characteristics in each ultrashort laser pulse. The results of the experiments carried out with the femtosecond laser system at the International Laser Center of the Moscow State University are presented.

The electron–ion scattering experiment ELISe is part of the installations envisaged at the new experimental storage ring at the International Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany. It offers an unique opportunity to use electrons as probe in investigations of the structure of exotic nuclei. The conceptual design and the scientific challenges of ELISe are presented.

An analysis of errors connected with beam pulse width variation and instrument noise characteristics has been carried out for charge monitoring of a pulsed accelerator beam traversing an experimental target. The formulae necessary for the selection of optimum monitor and preamplifier parameters for a given range and required accuracy are presented.

Absolute cross sections of the electron elastic scattering by a carbon nucleus have been measured in the range of momentum transfers of q/sup 2/=0.037-0.39 Fm/sup -2/ at the energy of incident electrons Esub(0)=27-87 MeV and at the scattering angles of 90 and 130 deg. Targets of pure graphite were installed so that the normal divided the the angle of scattering in half. The scattering angle was fixed with the error of +-0.5 mrad. The charge of electrons passed through the target was recorded by an induction sensor. The spectrum of elastically scattered electrons was taken on varying the magnetic field with a step from 1.5x10/sup -4/ to 5x10/sup -4/ in momentum. The statistical error of a separate spectrum point amounted to about 2.5%. The data obtained were processed in the se cond Born approximation. The value of the root-mean-square radius of a /sup 12/C nucleus was determined by two methods: by the generalized harmonic model (rsup(2))sup(1/2)=2.45 +- 0.25 Fm and by the model-independent met12%.