Surface nanoscale axial photonics structures introduced by bending of optical fibers

The new manufacturing method for fabrication of Surface Nanoscale Axial Photonics (SNAP) structures has been developed. We showed experimentally that the bent fiber can achieve the nanometer-scale variation in the effective fiber radius sufficient for fabrication of SNAP microresonators. The advantage of the demonstrated method is in its simplicity, robustness, and mechanical tunability of the fabricated devices

Production of the short-lived radionuclides for positron-emission tomography: cyclotron or linear electron accelerator

Analysis of the methods of the short-lived positron emitting radionuclides production on linear electron accelerators for positron-emission tomography (PET) was performed. Methods of extraction of short-lived isotopes from the irradiated samples are considered. It is shown that specific activity of radionuclides produced on linear electron accelerators is sufficient for the gamma-camera and PET diagnostic.Проведено аналіз методів напрацювання недовгоживучих радіонуклідів на лінійних прискорювачах електронів для позитронної емісійної томографії. Розглянуто методи здобування недовгоживучих ізотопів із опромінених зразків. Показано, що питома активність радіонуклідів, одержаних на лінійних прискорювачах електронів, може бути достатньою для діагностики на гамма-камерах та для позитронної емісійної томографії.Проведен анализ методов наработки короткоживущих радионуклидов на линейных ускорителях электронов для позитронной эмиссионной томографии. Рассмотрены методы извлечения короткоживущих изотопов из облученных образцов. Показано, что удельная активность радионуклидов, полученных на линейных ускорителях электронов, может быть достаточной для диагностики на гамма-камерах и для позитронной эмиссионной томографии

1.2 GeV electron radiation spectra in thick tungsten single crystals and total radiation losses in tungsten, germanium and silicon single crystals

The experimental investigation of radiation energy losses of ultra relativistic electrons in aligned crystals of various atomic number are of great interest for several reasonye

Intensive X-ray source optimization

Possibility of optimization of an intensive source of the electron radiation in crystals based on the Compton scattering of X-radiation is considered.Розглядається можливість оптимізації джерел інтенсивного рентгенівського випромінювання прискорених електронів з використанням методики на основі комптонівського розсіяння.Рассматривается возможность оптимизации источников интенсивного рентгеновского излучения ускоренных электронов с использованием методики на основе комптоновского рассеяния

Orientation effects in ultrarelativistic electron transmission through a single crystal

The results of experimental investigations of the 1.2 GeV electron transmission dynamics in a thin single crystal of Si are discussed. The interpretation of the electron scattering orientation dependencies measured under different scattering angles is carried out. The existence of scattering direction, where one can observe the scattering intensity independence on the crystallographic plane orientation is shown. Besides the existence of crystallographic axis orientation, where one can observe the region of uniform angle distribution of scattering intensity, is shown

Photonuclear transmutation doping of the n-type detector silicon

New experimental quantitative data on the efficiency of photonuclear transmutation doping of n-type detector silicon were obtained. The express technique for measurement of the efficiency of producing the acceptor minority (Al) in high resistant detector silicon was developed. The transmutation doping is studied for increase of the detector silicon resistivity from about 1 to 5 kOhm x cm and for correction of the resistivity distribution over the silicon bulk. The studies of photonuclear doping were performed applying the beams of gamma-bremsstrahlung with Egmax ~ 25 MeV. Using the doping efficiency data, the cost of detector silicon doping was calculated for case of the bremsstrahlung of 25 MeV energy electrons

Silicon pad detectors for a simple tracking system and multiplicity detectors creation

Silicon pad detectors are working at room temperatures, what is very convenient for creation of simple tracking system and multiplicity detectors. Silicon pad detectors are studied to create a compact detecting systems for active beam collimation and for gamma-radiation multiplicity measurements. The registration efficiency and spectral distributions of gamma-radiation and electrons were studied using isotope radiation sources. The silicon pad detectors were designed at NSC "KIPT"