Abstract A portable monoenergetic 24 keV neutron source based on the 124 Sb- 9 Be photoneutron reaction and an iron filter has been constructed characterized. The coincidence of energy from SbBe low interaction cross-section with (mean free path up to 29 cm) makes pure specially suited shield against gamma rays Sb decays while letting through neutrons. To increase activity thus flux, a >1 GB...

Background: High-energy linear accelerator (linac) is a valuable tool and the most commonly device for external beam radiation treatments in cancer patients. In the linac head, high-energy photons with energies above the threshold of interaction produce photoneutrons. These photoneutrons deliver the extra dose to the patients in the planning treatment and increase the risk of secondary cancer.O...

abstract background: with respect to the difference in the interaction of thermal neutron and x rays with matter, using two radiography systems of thermal neutron and x rays will yield highly valuable information for studying the inner structure of biologic samples. methods: the high sensitivity of thermal neutron to hydrogen, in particular, has led to recognizing this system as a useful tool i...

The possible effect of contrails in modifying the weather is reconsidered in the light of information obtained from ground-level contrails in Alaska. It appears likely that inadvertent cloud seeding b y jet aircraft may be of the same order of magnitude as that attained in commercial cloud seeding operations. Further investigation is needed; but in the meantime, the possibility of contrail cont...

Out-of-field doses from radiotherapy can cause harmful side effects or eventually lead to secondary cancers. Scattered doses outside the applicator field, neutron source strength values, and neutron dose equivalents have not been broadly investigated for high-energy electron beams. To better understand the extent of these exposures, we measured out-of-field dose characteristics of electron appl...