E. A. Simonov

Experimental investigation of high-energy photon splitting in atomic fields

Data analysis of an experiment in which photon splitting in atomic fields was observed is presented. The experiment was performed at the tagged photon beam of the ROKK-1M facility at the VEPP-4M collider. In the energy region of 120-450 MeV, statistics of 1.6x10(9) photons incident on the BGO target was collected. About 400 candidate photon-splitting events were reconstructed. Within the attained experimental accuracy, the experimental results are consistent with the calculated exact atomic-field cross section. The predictions obtained in the Born approximation differ significantly from the experimental results.

A detailed test of the CsI(Tℓ) calorimeter for BELLE with photon beams of energy between 20 MeV and 5.4 GeV

Abstract The results of a beam test of a prototype of the BELLE CsI(Tl) calorimeter are reported. The test used beams of photons with energies spanning the range from 20 MeV to 5.4 GeV, produced at ROKK-1M facility of the Budker Institute of Nuclear Physics. The single-counter energy-equivalent noise was measured to be ∼200 keV. The design goals for the energy resolution, e.g. 4% at 20 MeV and 1.7% at 5.4 GeV, were achieved using the sum of energy deposits in a 5×5 crystal matrices with a single crystal energy threshold of 0.5 MeV; the summed energy deposit measured in the array corresponds to 97±2% of the incident photon energy over the entire energy range. The average position resolution for 470 MeV energy photons was measured to be 8 mm.

Delbrück scattering at energies of 140–450 MeV

The differential cross section of Delbr{u}ck scattering is measured on a bismuth germanate

Absolute calibration of particle energy at VEPP-4M

Bi_4Ge_3O_{12}

Study of characteristics of the BELLE CsI calorimeter prototype with a BINP tagged photon beam

target at photon energies

ROKK‐1M is the Compton source of the high intensity polarized and tagged gamma beam at the VEPP‐4M collider

140 - 450 MeV

The test of the LKr calorimeter prototype at the tagged photon beam

and scattering angles

Fissility of Bi, Pb, Au, Pt, W, Ta, V and Ti nuclei measured with 100 MeV Compton backscattered photons

2.6 - 16.6 mrad

Use of the methods of accelerator physics in precision measurements of particle masses at the VEPP-4 complex with the KEDR detector

. A good agreement with the theoretical results, obtained exactly in a Coulomb field, is found.

Photofission cross section and fissility of pre-actinide and intermediate-mass nuclei by 120 and 145 MeV Compton backscattered photons

We have started a new series of experiments on a precise measurement of J/Ψ-, Ψ′- mesons and τ-lepton masses at VEPP-4M collider with KEDR detector. Features of the method used for an absolute particle energy calibration based on the resonance depolarization are described.