OBJECTIVE To compare neutron treatment and megavoltage (photon) radiotherapy in locally advanced squamous cell carcinoma of the head and neck. DESIGN Randomised trial of patients stratified by site of primary tumour and presence or absence of lymph node metastases. Follow up of patients after treatment. SETTING Department of clinical oncology, Western General Hospital, Edinburgh. PATIENTS...

PURPOSE To evaluate the neutron and photon dose equivalent rate (H(n,D) and H(G)) at the outer maze entrance and the adjacent treatment console area after the installation of a Varian Clinac 23EX accelerator with a higher beam energy than its predecessor. The evaluation was based on measurements and comparison with several empirical calculations. The effectiveness of borated polyethylene (BPE) ...

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...

We report a fast neutron and gamma induced radiation dose and flux monitoring study during the nano-particle production at the proton beam irradiation facility. The monitoring results will be used for understanding of the activation of irradiated samples and the effect to the nano-particle production. A cylindrical shape of BC523A liquid scintillator was used for the fast neutron and gamma moni...

BACKGROUND The results of RTOG-MRC randomized trial of photon (n=15) versus neutron (n=17) therapy in the 1980's reported an improved local control (LC) with neutron radiotherapy for unresectable salivary gland tumors. Due to increased severe toxicity with neutron radiotherapy and the paucity of neutron-therapy centers, we analyzed our institution's results of photon radiotherapy for unresectab...

The most challenging type of reactors to convert to low-enriched fuel are high-flux research reactors, which, along with some spallation sources, are the most important neutron sources for modern neutron scattering experiments. Advanced Monte-Carlo computer codes are now available that make it possible to track neutrons from the reactor core, through neutron guides, to instruments and detectors...

Photosynthesis is fundamentally driven by photon flux rather than energy flux, but not all absorbed photons yield equal amounts of photosynthesis. Thus, two measures of photosynthetically active radiation have emerged: photosynthetic photon flux (PPF), which values all photons from 400 to 700 nm equally, and yield photon flux (YPF), which weights photons in the range from 360 to 760 nm accord...

We report the finding of an unusual, weak precursor to a thermonuclear X-ray burst from the accreting millisecond pulsar SAX 51808.4-3658. The burst in question was observed on Oct. 19, 2002 with the Rossi X-Ray Timing Explorer (RXTE) proportional counter array (PCA). The precursor began M 1 s prior to the onset. of a strong radius expansion burst, lasted for about 0.4 s, and exhibited strong o...

We report the finding of an unusual, weak precursor to a thermonuclear X–ray burst from the accreting millisecond pulsar SAX J1808.4–3658. The burst in question was observed on Oct. 19, 2002 with the Rossi X-Ray Timing Explorer (RXTE) proportional counter array (PCA). The precursor began ≈ 1 s prior to the onset of a strong radius expansion burst, lasted for about 0.4 s, and exhibited strong os...

The 250kW TRIGA Mark II research reactor, Vienna, is equipped with experimental facilities inside and outside the reactor core. Outside the core, there are four beam tubes (three radial and one tangential beam tube), a thermal column and a neutron radiography collimator, supplying neutrons for irradiation experiments. These experiments include neutron radiography, neutron tomography, neutron ac...