Publ. Astron. Obs. Belgrade No. 89 (2010), 359-361 Contributed Paper 359 NEUTRON MEASUREMENTS IN SAHAND PLASMA FOCUS SAMAD SOBHANIAN 1 , M. A.MOHAMMADI 2,3 , MARYAM GOLALIKHANI 3 , MAHMOOD MOSLEHI-FARD 4 and SIRUS KHORRAM 2 1 Sciences and Research Unit of East Azerbaijan Islamic Azad Universit, Tabriz, Iran 2 Research Institute for Applied Physics and Astronomy, university of Tabriz 3 Faculty of Physics, university of Tabriz,Tabriz-Iran.4- Islamic Azad university, Tabriz branch, Department of physics ,Tabriz/Iran E-mail: sobhanian@tabrizu.ac.ir Abstract. Experimental studies of neutron emission from a Filippov type plasma focus machine is reported here for different pressures and voltages in deuterium gas. The calibra- tion method is discussed and time integrated and time resoled neutron signals and also the angular distribution anisotropy are studied in order to clarify the most probable mechanism for neutron production. The results showing the enhancement of neutron yield in the case of some krypton admixture is also presented. 1. INTRODUCTION Plasma focus device is known as a powerful and excellent source of soft and hard x-rays,energetic ions and electrons as well as neutrons. Dense plasma focus(DPF) operation principles are given in different references (Filippov et al. 1962, Mather 1964, Siahpoush et al. 2005). Different stages are: the initial discharge state be- tween the anode and ring-like insulator, the current sheet formation, ionization and capture of neutral gas (snow-plow model), accelerated motion of plasma current sheet (PCS), formation of non-cylindrical shock wave, development of instabili- ties, generation of x-rays and neutrons and finally the interaction of decayed plas- ma with electrodes surfaces. Using deuterium as the filling gas in the discharge chamber, fusion neutrons produced by D-D nuclear reaction are emitted from the device. The mechanism for neutron production in pinched plasmas is not exactly clear. There are two main mechanisms for neutron production in DPF devices. In one of these mechanisms, it is assumed that neutrons are generated in D-D reac- tion through collisions between deuterons. In the second likely mechanism, the ac- celerated deuterons colliding with thermal deuterons in the plasma bulk produce neutrons as the result of beam-target collision. The anisotropy shown in neutron and x-rays emission suggests that beam-target processes may be partly responsible for neutron generation. We give in this paper the variation of neutron yield as