The design and the characteristics of a drift tracker for the SVD-2 setup at the U-70 accelerator of the Institute for High Energy Physics (Protvino, Russia) are described. The drift tracker has been developed to improve the quality of track reconstruction in high-multiplicity events. It is composed of 2304 drift tubes with a diameter of 6 mm and a sensitive region 500–900 mm long. The distance between a track and the anode wire is determined from the drift time. The coordinate resolution and the detection efficiency of the tubes have been determined from the data of the accelerator run in 2006.
Описывается прецизионный вершинный микростриповый детектор, созданный для установки “Спектрометр с вершинным детектором”, на которой исследуются свойства адронов и короткоживущих нестабильных частиц на ускорителе ГНЦ “Институт физики высоких энергий”. Приведены структура, конструкция и технология изготовления основных компонентов детектора микростриповых сенсоров и активной мишени; описываются также электроника съема и регистрации сигналов, система сбора данных и ее программное обеспечение. Точность определения положения вершин составляет 70250 мкм вдоль оси пучка и 815 мкм поперек оси при быстродействии 5001000 событий/с.
A precision vertex microstrip detector has been developed for the spectrometer with a vertex detector (SVD) setup on which the properties of hadrons and short-lived unstable particles are investigated on the accelerator of the Institute for High Energy Physics. The structure and the design of the main detector components—microstrip sensors and an active target—are presented, as well as techniques for manufacturing them. The readout electronics, the data acquisition system, and its software are also described. The accuracy in determining the vertex position is 70–250 µm along the beam axis and 8–15 µm in a transverse direction at a throughput of 500–1000 events/s.
The methods for reconstructing the coordinates of charged-particle tracks in silicon microstrip detectors are analyzed thoroughly. It is shown that the accuracy depends on the reconstruction procedure. The methods are applied to model calculations with the GEANT program of the SVD vertex detector in the experiment E-184.
A new method for the charged-particle track recognition and reconstruction in a hybrid wide-aperture spectrometer with a vertex detector is described. The proposed variable-momentum method is based on a simple procedure of fitting the particle momentum in the spectrometer by the angular track characteristics and interaction-vertex coordinates, measured in the vertex detector. The characteristics of the new and conventional methods are analyzed and compared. Many of the advantages of the new method are shown. The method was evaluated by analyzing the events of the proton-proton interactions at 70-GeV energy, which were recorded in the spectrometer with the vertex detector at the IHEP accelerator. The results of the evaluation are presented.