introduction: image quality and accuracy of in vivo activity quantification in spect are affected by collimator penetration and scatter components, especially in high energy imaging. these phenomena highly depend on the collimator characteristic and photon energy. the presence of penetrated and scattered photons from collimator in spect images degrades spatial resolution, contrast and image qua...

The applicability of the dual-wavelength reflectance-ratio (DWR) method to emissivity-free radiation thermometry electromagnetically levitated high-temperature liquid metals was investigated. To establish measurement technique, DWR applied Ni in a static magnetic field, which suppresses surface oscillation and translational motion. In previous study, temperature measured by showed deviations ab...

Vehicle speed guns are usually used in normal sunlight conditions (daytime). If we want to use vehicle low light (nighttime), the illuminator is needed provide sufficient for gun take photos. The must fulfill two requirements: (i) using infrared wavelength ensure that driver not startled by dazzling eyes of proposed system and (ii) high energy efficiency make compact leading a small battery imp...

The importance of collimator R&D with test beam facilities is demonstrated with the example of ILC collimator studies at SLAC End Station A. Related LHC collimator aspects and longer term plans are addressed. Presented at IDTB07, ILC Detector Test Beam workshop, Fermilab, USA, 2007.

Because background radiation in an irradiation room creates a problem with the PG-SPECT (Prompt Gamma-ray Single Photon Emission Computed Tomography) system, which evaluates the absorbed dose for the Boron Neutron Capture Therapy treatment, optimization of a collimator system was performed while taking the shielding of background gamma-rays into consideration. Assuming that a parallel-beam coll...

An integrated imaging sensor system is being developed to enhance operations of robots and telerobotic systems used in nuclear industry . This system combines a gamma ray image of the distribution of radioactivity with a video image of the area, allowing a rapid and intuitive determination of the source location . The gamma ray imaging system is based upon a position sensitive photomultiplier t...

Collimator systems used in Intensity Modulated Radiation Therapy can form different geometric aperture shapes depending on their physical capabilities. We compare the efficiency of using regular, rotating and dual multileaf collimator (MLC) systems under different combinations of consecutiveness, interdigitation and rectangular constraints. We also create a virtual freeform collimator, which ca...

To more easily estimate accurate values of collimator scatter facor, S(c), we suggest a two-component saturation model that accounts for scatter from the primary collimator and flattening filter and from the collimator jaws. This model, which assumes an exponential distribution of scatter intensity, was tested by in-air measurements using a mini-phantom for 4 MV and 10 MV X-rays of a Clinac 210...