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SUMMARY:Registration of neutrons using scintillation detectors in the magn
 etic field of the HELIS facility
DTSTART;VALUE=DATE-TIME:20241024T133000Z
DTEND;VALUE=DATE-TIME:20241024T140000Z
DTSTAMP;VALUE=DATE-TIME:20260518T065718Z
UID:indico-contribution-4200@cern.ch
DESCRIPTION:Speakers: Mikhail Kirsanov (MEPhI)\, Sergey Klimanov (National
  Research Nuclear University MEPhI (Moscow Engineering Physics Institute))
 \, Mikhail Negodaev (P.N. Lebedev Physical Institute of the Russian Academ
 y of Sciences)\nScintillation detectors are successfully used to register 
 fast neutrons in the presence of background gamma radiation. However\, whe
 n scintillation detectors operate near particle accelerators\, a problem a
 rises due to the presence of a magnetic field near the accelerator.\nIn th
 is paper we investigate the influence of the magnetic field of the HELIS a
 ccelerator facility on the parameters of scintillation detector signals an
 d on the efficiency of separating signals from neutrons and gamma quanta. 
 Each detector contains organic monocrystal p-terphenyl and a Hamamatsu R60
 94 photomultiplier tube. The signals from the photomultiplier tube outputs
  are digitized using a CAEN DT5730 Digitizer. \nThe gamma-quantum sources 
 Cs-137 and Co-60 were used to study the change in the amplitude and shape 
 of the detector signals at different locations of the PMT dynode system re
 lative to the magnetic field. The presence of a magnetic field leads to a 
 decrease in the amplitude of the signals and distortion of their shape.\nU
 sing the Cf-252 neutron source\, the dependence of the efficiency of signa
 l separation from neutrons and gamma quanta on the magnetic field strength
  was studied. In the absence of a magnetic field\, the coefficient of effi
 ciency of signal separation Figure of Merit is FOM=1.5. At a magnetic fiel
 d of 0.5 mT\, the efficiency of signal separation from neutrons and gamma 
 quanta (detectors without a magnetic shield) decreases to FOM=1\, and at a
  field of ≈ 1 mT\, it becomes impossible to separate the signals. The us
 e of PMTs with magnetic shields allows neutrons to be registered without d
 eterioration of the efficiency of signal separation in magnetic fields up 
 to 5 mT.\nIt has been demonstrated that scintillation detectors with magne
 tic screens effectively register fast neutrons at the HELIS accelerator fa
 cility.\n\nhttps://indico.particle.mephi.ru/event/436/contributions/4200/
LOCATION:Hotel Intourist Kolomenskoye 4*
URL:https://indico.particle.mephi.ru/event/436/contributions/4200/
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