background: neutron contamination in our environment can cause harmful biological effects on human body. therefore, many efforts have been made to construct a neutron dosimeter to estimate the received dose. objective: to design a simple neutron dosimeter. methods: the primary dosimeter had 3he as a spherical thermal neutron detector encircled by paraffin 10 cm in radius. then, the paraffin sph...

With the use of theory developed earlier, bulk effects in ultracold neutron coherent inelastic scattering are considered both for solid and liquid target samples related to energy and momentum exchange with phonon and diffusion-like modes. For the neutron in a material trap, differential and integral probabilities for the energy transfer per bounce are presented in a simple analytic form which ...

forty seven sediment cores recovered from the south china sea coasts along the east coast of peninsular malaysia were analysed for as, cd, cr, cu, hg, ni, pb and zn using instrumental neutron activation analysis. the results indicate a homogeneous distribution except for as and pb in all stations. assessment of heavy metal pollution in marine sediments requires knowledge of pre-anthropogenic me...

The use of epithermal neutron beam in clinical trials of Boron Neutron Capture Therapy for patients with malignant brain tumors had been carried out for half a decade at the Brookhaven's Medical Reactor. The decision to permanently close this reactor in 2000 cut short the efforts to implement a new conceptual design to optimize this beam in preparation for use with possible new BNCT protocols. ...

Using neutron reflectivity, we found that there is no intrinsic depletion layer at a deuterated polystyrene (dPS) film and deuterium oxide (D(2)O) interface. A spun-cast film is susceptible to contamination on its surface from its surroundings during sample preparation. A contamination layer of hydrogenated organic material will be detected as a reduced scattering length density layer at the in...

In this paper, the contamination level of fourteen elements (Al, Ca, Mg, V, Ti, Na, Mn, As, Br, La, Sm, Sc, U, Yb) from different soil samples of the nuclear reactor surrounding areas in Savar, Bangladesh was investigated with instrumental neutron activation analysis (INAA) method. Generally, neutron activation is most reliable tool for determining the concentration of the trace elements and he...

An often overlooked problem in the use of radiotracers is the possibility of isotopic contamination. Commercially available silver 110mAg was used to study silver uptake and depuration in rainbow trout and European eel. Quality control by means of comparative gamma and beta counting brought our attention to a contamination of the 110mAg stock with 109Cd, which could be seen only because the 109...

Bystander effects have been observed repeatedly in mammalian cells following photon and alpha particle irradiation. However, few studies have been performed to investigate bystander effects arising from neutron irradiation. Here we asked whether neutrons also induce a bystander effect in two normal human lymphoblastoid cell lines. These cells were exposed to fast neutrons produced by targeting ...

At INFN LNL (Legnaro Italy) it has been built a high intensity Radio Frequency Quadrupole (RFQ) structure, able to produce a 5 MeV proton beam of 30 mA. Coupled with a Be target such a beam can generate a neutron flux of 1014 n/s, with a spectrum centred in the MeV region (that has been recently characterized in detail at LNL accelerators). This neutron flux can be moderated to generate a therm...

BACKGROUND Electron linear accelerators in medical radiotherapy have replaced cobalt and caesium sources of radiation. However, medical accelerators with photon energies over 10 MeV generate undesired fast neutron contamination in a therapeutic X-ray photon beam. Photons with energies above 10 MeV can interact with the atomic nucleus of a high-Z material, of which the target and the head of an ...