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Information × Registration Number 0215U004436, 0114U007357 , R & D reports Title Participation in service of a hadron calorimeter of the detector CMS and its modernization for conditions of the increased luminosity of the Large Hadron Collider popup.stage_title Head Sorokin Pavel Vladimirovich, Registration Date 16-04-2015 Organization National Science Center "Kharkiv Institute of Physics and Technology popup.description2 Studying of dependence of degradation of a light yield on dose power for SCSN-81 scintillator (Kuraray, Japan) is continued from which active elements of a hadron calorimeter (HCAL) to the detector CMS are made. Radiation was carried out by brake photons on linear accelerators of electrons of NSC KIPT of 10 MEV to an integrated dose 4.3 Mrad at rate of 0.23, 0.12 and 0.018 Mrad / hour. The damage rate of scintillator was determined by the size of the relation of position of the center ?-пика (a source 239Pu) after radiation before position of the center ?-пика before radiation. It is shown that the light yield at the minimum power of a dose makes only 54% of size which answers unirradiated samples. The results received in NSC KIPT allowed to explain also an essential difference between real reduction of a signal from active elements of face hadron calorimeters (HE) of CMS after end of the first session of measurements on a superkolayder of LHC and the estimates made at a CMS installation design stage. Radiation of samples of SCSN-81 and UPS scintillators - 923a is executed (ISMA, Kharkov) at rather small (20 крад / hour) dose capacities in pure (99.9%) nitrogen, the light yield from these samples is also measured. Radiation in pure nitrogen didn't lead to any increase in radiation firmness for both types of scintillators. Also research of radiation firmness of liquid EJ-309 scintillator (Eljen Tech is executed., the USA) which has high brightness and it is considered perspective option of replacement for SCSN - 81. For a portion of EJ-309 which was isolated from air at radiation to 5 Mrad at rate of 0.16 Mrad / hour, any degradation of a light yield within errors of measurements (±0.03%) it isn't recorded. Contact of a surface of scintillator with air in the course of radiation brings to ~ to 2-fold reduction of a signal. Results on studying of radiation firmness of scintillators which were received in NSC KIPT within implementation of this project, were reported at seminars and conferences of experiment of CMS, and these results were confirmed in FNAL (USA) and in other laboratories of the world. Product Description popup.authors Бунецький Олег Олегович Горбенко Євген Степанович Кізка Валерій Олександрович Кліменко Кім Олександрович Левчук Леонід Геннадійович Лук'яненко Сергій Тимофійович Попов Віктор Пилипович Приставка Олександр Сергійович Сорокін Павло Володимирович popup.nrat_date 2020-04-02 Close