Design, Commissioning and Performance of the PIBETA Detector at PSI

We describe the design, construction and performance of the PIBETA detector built for the precise measurement of the branching ratio of pion beta decay, pi+ -> pi0 e+ nu, at the Paul Scherrer Institute. The central part of the detector is a 240-module spherical pure CsI calorimeter covering 3*pi sr solid angle. The calorimeter is supplemented with an active collimator/beam degrader system, an active segmented plastic target, a pair of low-mass cylindrical wire chambers and a 20-element cylindrical plastic scintillator hodoscope. The whole detector system is housed inside a temperature-controlled lead brick enclosure which in turn is lined with cosmic muon plastic veto counters. Commissioning and calibration data were taken during two three-month beam periods in 1999/2000 with pi+ stopping rates between 1.3*E3 pi+/s and 1.3*E6 pi+/s. We examine the timing, energy and angular detector resolution for photons, positrons and protons in the energy range of 5-150 MeV, as well as the response of the detector to cosmic muons. We illustrate the detector signatures for the assorted rare pion and muon decays and their associated backgrounds.Comment: 117 pages, 48 Postscript figures, 5 tables, Elsevier LaTeX, submitted to Nucl. Instrum. Meth.

ТОТАЛЬНОЕ ЭНДОПРОТЕЗИРОВАНИЕ ТАЗОБЕДРЕННОГО СУСТАВА С ИСПОЛЬЗОВАНИЕМ АУГМЕНТОВ ИЗ ТРАБЕКУЛЯРНОГО МЕТАЛЛА ПРИ ПОСЛЕДСТВИЯХ ПЕРЕЛОМОВ ВЕРТЛУЖНОЙ ВПАДИНЫ

The authors presented the experience of treatment of two patients with hip arthritis after acetabular fracture. Both patients were treated with total hip replacement. During the operation, to manage posterior-superior bone defects of the acetabulum, augments of trabecular metal were used. Pain and limitation of motions in hip were indications for operative treatment. After a year of follow up there was no pain in hip; also recovery of motion and improved quality of life were observed.Представлен опыт тотального эндопротезирования тазобедренного сустава у двух пациентов с последствиями переломов вертлужной впадины. Во время операции для замещения костного дефекта задневерхнего отдела вертлужной впадины были использованы аугменты из трабекулярного металла. Показанием к оперативному вмешательству явились боль и ограничение движений в тазобедренном суставе. Спустя год после операции пациенты отмечают отсутствие болей, увеличение амплитуды движений, улучшение качества жизни