Experimental investigation of high-energy photon splitting in atomic fields

The new data analysis of the experiment, where the photon splitting in the atomic fields has been observed for the first time, is presented. This 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, the statistics of $1.6\cdot 10^9$ photons incident on the BGO target was collected. About 400 candidates to the photon splitting events were reconstructed. Within the attained experimental accuracy, the experimental results are consistent with the cross section calculated exactly in an atomic field. The predictions obtained in the Born approximation significantly differ from the experimental results.Comment: 11 pages, 6 figures, LaTe

Status of VEPP-4M collider: current activity and plans

Presented are the results of a VEPP-4M collider operation at Budker Institute of Nuclear Physics during 2004-2005 as well as the plans for the nearest future.Представлены результаты, полученные на накопителе ВЭПП-4М Института Ядерной физики им. Будкера, за период 2004-2005 г., а также планы на ближайшее будущее.Представлено результати, отримані на накопичувачі ВЕПП-4М Інституту Ядерної фізики ім. Будкера, за період 2004-2005 р., а також плани на найближче майбутн

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

Alors qu’avec les plate-formes collaboratives la formation à distance tend à participer d’un modèle pédagogique socioconstructiviste, comment des étudiants habitués à l’enseignement transmissif en présentiel (s’)adaptent-ils (à) ce nouveau mode d’apprentissage ? Analysant les relevés d’activité et entretiens effectués auprès d’apprenants préparant le diplôme d’accès aux études universitaires (DAEU) à distance, nous observons que les usages réservés aux outils ne correspondent pas toujours à ceux prévus. Nous interrogeons alors la pertinence de ce modèle technico-pédagogique dans le cadre de la préparation d’examens fondés sur une restitution de savoirs évaluée individuellement.   <br>As students have been used to face-to-face teaching, we wonder how they adapt to the socio-constructivist type of pedagogy implemented by collaborative platforms through e-learning. We carried out analyses based on activity statements and interviews with learners who suspended their education, but are now preparing to continue their education via on-line education. The use of different technologies allows us to think about the large field of e-learning practices which do not always correspond to those envisioned. We then question the point of such a technico-pedagogic model for preparing for exams based on individually evaluated restitutions of academic knowledge