We have studied the structure of the Borromean nucleus Li via the Coulomb breakup with a Pb target at 70 MeV/nucleon. Momentum vectors of the breakup particles, Li and two neutrons, were measured in coincidence to reconstruct the B(E1) energy spectrum. The strong E1 transitions were observed at Erel ∼ 0.3 MeV with the B(E1)=1.42(18)efm (=4.5(6)W.u.), which is the largest E1 strength ever observ...

Neutron sources employed in different applications in both medicine and industry. Due to the harmful effects of neutron particles on living organisms, radiation shields have played a vital role in radiation protection against neutrons. In recent decade, numerous investigations conducted on the design and fabrication of nanocomposites as more efficient shielding materials against fast and therma...

We report progress on an experiment to measure the neutron lifetime using magnetically trapped neutrons. Neutrons are loaded into a 1.1 T deep superconducting Ioffe-type trap by scattering 0.89 nm neutrons in isotopically pure superfluid (4)He. Neutron decays are detected in real time using the scintillation light produced in the helium by the beta-decay electrons. The measured trap lifetime at...

Medical linear accelerators are one of the most widespread methods for cancer treatment. Despite their advantages, unwanted photoneutrons are produced by high energy linacs. This photoneutrons are as undesired doses to patients and a significant problem for radiation protection of the staffs and patients. Photoneutrons radiological risk must be evaluated because of their high LET and range.in o...

Neutrons constitute a major component in the radiation fi eld outside the shielding of particle accelerators. Consequently appropriate neutron dose meters are needed to survey the radiation levels. A thermo-luminescence based neutron dosemeter is used at the UNILAC as well as at the SIS. It has been modifi ed to improve the response for high energetic neutrons (extended range). We report on a t...

The production of fast neutrons (1 MeV 1 GeV) in high energy muon-nucleus interactions is poorly understood, yet it is fundamental to the understanding of the background in many underground experiments. The aim of the present experiment (CERN NA55) was to measure spallation neutrons produced by 190 GeV/c muons scattering on carbon target. We have investigated the energy spectrum and angular dis...

Fast neutrons are useful for activation analysis of several light elements. For example, oxygen analyses are routinely made in our reactor laboratory and elsewhere by the 160(n, p)]6N reaction. The threshold for this reaction is over 10 MeV. Napier et al. ~) have described a device which was intended to convert thermal neutrons into 14 MeV neutrons by the reaction sequence 6Li(n, o~)3H ... 2H(3...

Nuclear power production can benefit from the development of more comprehensive alternatives for dealing with long-term radioactive waste. One such alternative is an accelerator-driven subcritical reactor (ADSR) which has been proposed for both energy production and for burning radioactive waste. Here we investigate the effects of the size of the ADSR spallation target on the total neutron yiel...