A novel three-dimensional non-destructive beam monitor named pi.sup.3 was conceived, realized and tested. It is based on a thin aluminum foil coated with P47 scintillating material mounted on a ...support, together with a miniaturized CCD camera, both moving along the beam axis. This detector allows reconstructing of the beam distribution along the beam path, providing either an on-line video or a graphical reconstruction of the beam envelope in 3D. The pi.sup.3 detector is a general-purpose instrument suitable for any ion accelerator facility. As it is constructed with non-magnetic materials, it can be used to investigate the behavior of the beam inside beam optics components such as magnets. In this paper, we report the development of the first prototype of the pi.sup.3 detector, its associated software and the results of the beam tests performed at the Bern medical cyclotron laboratory. Keywords: 3D beam monitor; beam envelope; particle detector; particle accelerator; cyclotron
The future development of personalized nuclear medicine relies on the availability of novel medical radionuclides. In particular, radiometals are attracting considerable interest since they can be ...used to label both proteins and peptides. Among them, the β
-emitter
Ga is widely used in nuclear medicine for positron emission tomography (PET). It is used in theranostics as the diagnostic partner of the therapeutic β
-emitters
Lu and
Y for the treatment of a wide range of diseases, including prostate cancer. Currently,
Ga is usually obtained via
Ge/
Ga generators. However, their availability, high price and limited produced radioactivity per elution are a major barrier for a wider use of the
Ga-based diagnostic radiotracers. A promising solution is the production of
Ga by means of proton irradiation of enriched
Zn liquid or solid targets. Along this line, a research program is ongoing at the Bern medical cyclotron, equipped with a solid target station. In this paper, we report on the measurements of
Ga,
Ga and
Ga production cross-sections using natural Zn and enriched
Zn material, which served as the basis to perform optimized
Ga production tests with enriched
Zn solid targets.
The degree to which non-human primate behavior is lateralized, at either individual or population levels, remains controversial. We investigated the relationship between hand preference and posture ...during tool use in chimpanzees (
Pan troglodytes) during bipedal tool use. We experimentally induced tool use in a supported bipedal posture, an unsupported bipedal posture, and a seated posture. Neither bipedal tool use nor these supported conditions have been previously evaluated in apes. The hypotheses tested were 1) bipedal posture will increase the strength of hand preference, and 2) a bipedal stance, without the use of one hand for support, will elicit a right hand preference. Results supported the first, but not the second hypothesis: bipedalism induced the subjects to become more lateralized, but not in any particular direction. Instead, it appears that subtle pre-existing lateral biases, to either the right or left, were emphasized with increasing postural demands. This result has interesting implications for theories of the evolution of tool use and bipedalism, as the combination of bipedalism and tool use may have helped drive extreme lateralization in modern humans, but cannot alone account for the preponderance of right-handedness.
The interferometric gravitational wave detectors represent the ultimate evolution of the classical Michelson interferometer. In order to measure the signal produced by the passage of a gravitational ...wave, they aim to reach unprecedent sensitivities in measuring the relative displacements of the mirrors. One of them, the 3-km-long Virgo gravitational wave antenna, which will be particularly sensitive in the low-frequency range (10–100
Hz), is presently in its commissioning phase. In this paper the various techniques developed in order to reach its target extreme performance are outlined.
We monitored the acoustic emission activity of the steel blades to be used for the mirror suspension system of a gravitational wave interferometer. We have collected several sets of events getting ...evidence of a material memory effect (Kaiser effect) associated to the dislocation motion in the steel. This result is more evident when we apply a standard fractal analysis procedure (box counting method) to the timing series of acoustic emission bursts. We conclude that a significant reduction of the emission rate is obtained by applying a few stress cycles to the elastic blades.
The possibility of obtaining geophysical information from the system for controlling the position of the mirrors of the VIRGO laser-interferometric gravitational antenna and from angular ...perturbations of the vertical mirror lines is examined. Results from a study of tidal horizontal deformations are analyzed.
PDF
