Neutron Spectrometer GNEIS

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NEUTRON TIME-OF-FLIGHT SPECTROMETER GNEIS in B.P. Konstantinov Petersburg Nuclear Physics Institute of Russian Academy of Sciences

The GNEIS - the Gatchina neutron time-of-flight spectrometer - is based at the 1 GeV proton synchrocyclotron in Petersburg Nuclear Physics Institute of Russian Academy of Science. GNEIS is intended for investigations of neurton interaction with atomic nuclea in wide energy range from 10^-2 eV up to hundreds MeV. The results of experiments performed with GNEIS facility are presented at page "Results".
The pulse neutron sourse consists with water-cooled lead target and polyethylene moderator placed inside the vacuum chamber of the accelerator.

The main parameters of pulsed neutron source are as follows:

- internal water-cooled rectangular lead target	40 cm ´ 20 cm ´ 5 cm
- rectangular polyethylene moderator	30 cm ´ 10 cm ´ 5 cm
- proton beam energy	1 GeV
- average proton beam current	2.3 mA
- duration of the fast neutron pulse	~ 10 ns
- repetition rate	50 Hz (or less)
- average fast neutron intensity	~ 3·10¹⁴ n/s

Five neutron beams are transported outside the vacuum chamber of the synchrocyclotron through the shielding wall of the machine main room and evacuated flight paths in the GNEIS laboratory building. One beam # 5 axis looks at the lead neutron-production target and others # 1-4 look at the moderator. The 35 - 50 m flight path lengths are determined by dimensions of the experimental area. Space of experimental area (GNEIS building) is 45 ´ 30 m².

General layout of the GNEIS facility:

The comparison of the energy resolution and neutron intensity of GNEIS with the analogous parameters of the other well known TOF-facilities (e.g. IBR-30, LANSCE) shows that GNEIS competes successfully in its energy range. Detaled description of GNEIS facility and demonstration its experimental possibilities are presented at page "Facility". Other GNEIS detales are presented at pages as follows:

How to contact with us:

	Address:	Petersburg Nuclear Physics Institute Gatchina, Leningrad district 188300 Russia
	Phone :	+ 7 - 81271 - 46444
	Fax :	+ 7 - 81271 - 36041
	Email :	shcherba@pnpi.spb.ru laptev@pnpi.spb.ru
	ICQ :	26396187