Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: dose equivalent

Sortuj według:

Ogranicz wyniki do:

Międzynarodowe podstawowe normy ochrony przed promieniowaniem i bezpieczeństwa źródeł promieniowania

Musiałowicz T.

Postępy Techniki Jądrowej

2015

z. 3

15--22

W artykule omówiono wydaną w roku ubiegłym przez MAEA publikację zawierającą „MIĘDZYNARODOWE PODSTAWOWE NORMY OCHRONY PRZED PROMIENIOWANIEM I BEZPIECZEŃSTWA ŹRÓDEŁ PROMIENIOWANIA”. Odrębnie scharakteryzowano wymagania dotyczące różnych sytuacji narażenia: planowanego narażenia, wyjątkowego narażenia i istniejącego narażenia. W zakończeniu artykułu, jego autor i współautor poprzednich wydań NORM (1967, 1996), przedstawia swoją opinię na temat omawianej publikacji.

New IAEA publication entitled “Radiation Protection and Safety of Radiadion Sources: International Basic Safety Standards”. (No.GSR PART 3 IAEA) was described in the paper. The main parts of that publication concerning different exposure situations: planned exposure, emergency exposure, existing exposure are discussed separately. In the conclusion author of the article and simultaneously co-author of former editions (1967, 1996) of the BESIC SAFETY REQUIREMENTS presents his own opinion on the described book.

A study of the photoneutron dose equivalent resulting from a Saturne 20 medical linac using Monte Carlo method

Hashemi F., Hashemi-Malayeri B., Raisali G., Shokrani P., Sharafi A.

Nukleonika

2007

Vol. 52, nr 1

39-43

High energy linacs have several advantages including lower skin dose and higher dose rate at deep sighted tumors. But, at higher energies photonuclear reactions produce neutron contamination. Photoneutron contamination has been investigated from the early days of modern linacs. However, more studies have become possible using Monte Carlo codes developed in recent years. The aim of this study was to investigate the photoneutron spectrum and dose equivalent produced by an 18 MV Saturne linac at different points of a treatment room and its maze. The MCNP4C code was used to simulate the transport of photoneutrons produced by a typical 18 MV Saturne linac. The treatment room of a radiotherapy facility in which a Saturne 20 linac is installed was modeled. Neutron dose equivalent was calculated and its variations at various distances from the center of the X-ray beam was studied. It was noted that by increasing the distance from the center of the beam, fast neutrons decrease rapidly, but thermal neutrons do not change significantly. In addition, the photoneutron dose equivalent was lower for smaller fields. The fast photoneutrons were not recorded in the maze. It can be concluded that the fast photoneutrons are highly attenuated by concrete barrier, while the slow photoneutrons are increased. In addition, increasing the X-ray field size increases the photoneutron dose equivalent around the treatment room and maze. It seems that the walls play an effective role in increasing the photoneutron dose equivalent.