Author/Authors :
Skeppstedt، نويسنده , , Christine O. Paul-Roth، نويسنده , , H.A. and Lindstr?m، نويسنده , , L. and Wadsworth، نويسنده , , R. and Hibbert، نويسنده , , I. and Kelsall، نويسنده , , N. and Jenkins، نويسنده , , D. and Grawe، نويسنده , , H. and G?rska، نويسنده , , M. and Moszy?ski، نويسنده , , M. and Sujkowski، نويسنده , , Z. and Wolski، نويسنده , , D. and Kapusta، نويسنده , , M. and Hellstr?m، نويسنده , , M. and Kalogeropoulos، نويسنده , , S. and Oner، نويسنده , , D. and Johnson، نويسنده , , A. and Cederk?ll، نويسنده , , J. and Klamra، نويسنده , , W. and Nyberg، نويسنده , , J. and Weiszflog، نويسنده , , M. and Kay، نويسنده , , J. and Griffiths، نويسنده , , R. and Garces Narro، نويسنده , , J. and Pearson، نويسنده , , C. and Eberth، نويسنده , , J.، نويسنده ,
Abstract :
The mechanical design of the EUROBALL neutron wall and neutron detectors, and their performance measured with a 246,248Cm fission source are described. The array consists of 15 pseudohexaconical detector units subdivided into three, 149 mm high, hermetically separated segments and a smaller central pentagonal unit subdivided into five segments. The detectors are filled with Bicron BC501A liquid scintillator. Each section of the hexaconical detectors is viewed by a 130 mm diameter Philips XP4512PA photomultiplier while the sections of pentagonal detectors are viewed by Philips XP4312B PMTs. The tests of n–γ discrimination performed by zero-crossing and time-of-flight methods show a full separation of γ- and neutron events down to 50 keV recoil electron energy. These tests demonstrate the excellent timing properties of the detectors and an average time resolution of 1.56 ns. The factors determining the efficiency of neutron detectors are discussed. The total efficiency for the full array for a symmetric fusion-evaporation reaction is predicted to be 0.30.
