Design study on a microbeam system of Q/A=1/2 K100 cyclotron for biomedical and space radiation research

At the neutron time-of-flight facility n_TOF at CERN a new vertical beam line was constructed in 2014, in order to extend the experimental possibilities at this facility to an even wider range of challenging cross-section measurements of interest in astrophysics, nuclear technology and medical physics. The design of the beam line and the experimental hall was based on FLUKA Monte Carlo simulations, aiming at maximizing the neutron flux, reducing the beam halo and minimizing the background from neutrons interacting with the collimator or back-scattered in the beam dump.The present paper gives an overview on the design of the beam line and the relevant elements and provides an outlook on the expected performance regarding the neutron beam intensity, shape and energy resolution, as well as the neutron and photon backgrounds.

The SC200 proton therapy facility is consisting of a superconducting cyclotron, a gantry treatment room and a fixed beam room. The proton beams are transported mainly with beam transport devices, such as dipole magnets, quadrupole magnets, and corrector magnets which lie on the beam transport line layout of which is based on the beam optics design. A series of dipole, quadrupole, and corrector magnets ultimately make high-quality transmission of proton beams possible. Dipole magnets are mainly for beams deflection, quadrupole magnets are for beam focusing, and corrector magnets for orbit correction of beams. This paper shows the design of such magnets for the beam transport line. Besides, main parameters of magnets are presented and magnetic analysis work is also illustrated in this paper. The magnetic fields of dipole and quadrupole magnets are measured by hall mapping system and rotary coil measuring system. The results show that the measuring results are a little worse than the simulation results. However, both methods can meet the design requirement and the basic trend is similar to each other.

Iranian Light Source Facility (ILSF) is a 3 GeV Synchrotron light source with the circumference of 489.6m. Using locally available material and the emittance of less than 1 nm-rad are two main points of the ILSF storage ring lattice, consisting of 56 low field pure bending magnets, 252 quadrupoles and 196 sextupoles with additional coils for the correctors and skew quadrupoles. The physical designs of these magnets have been performed relying on two dimensional codes POISSON [1] and FEMM [2]. Three dimensional RADIA [3] was practiced too, to audit chamfering values. INTRODUCTION Using locally accessible materials has bound the beam dynamic group to utilize the magnets with upper field limits of 1.6 T for the dipoles, 0.8 T for the pole tip of quadrupoles and 0.4 T for the pole tip of sextupoles in their design [4].No gradient in the low field dipoles has been considered in the design stage of the lattice to ease alignment. The focusing in horizontal and vertical direction is performed in each super period with 8 focusing quadrupoles in three families and 10 defocusing quadrupoles in 4 families, with 14 sextupoles within 6 families [4]. All quadrupole magnets have the same cross section. This is the same for sextupole magnets that differ by their sextupole components and lengths. STORAGE RING MAGNETS Dipoles Through a none symmetric standard shim the field quality would be lower than 0.02% within the good field region ±18mm. Figure 1 shows the magnet’s dimensions and magnetic field lines inside one half of the dipole as simulated by “POISSON” code. Figure 1: Magnetic field lines and geometry of the dipole magnet in ILSF. Stainless steel M800-100A, a low-carbon ( The magnetic design of the magnets for ILSF storage ring is done and the magnets are now in the production phase. Using typical 2-D codes, POISSON and FEMM along with the 3-D code, RADIA, to provide an authentic investigation on the magnets end fields have been fruitful. REFERENCES [1] uspas.final.gov/PCprog [2] www.FEMM.info [3] www.esrf.fr/machine.groups/inserion_devices/Codes/ Radia/Radia [4] H. Ghasem, F. Saeidi, I. Ahmadi, “Low field low emittance lattice for the storage ring of Iranian Light Source Facility”, Journal of Instrumentation 8, P02023 (2013). [5] Jack Tanabe, “Iron Dominated Electromagnets Design, Fabrication, Assembly and Measurements”, SLAC-R-754, June 2005.

Summary form only given. Although it is often assumed that all light-matter interactions at optical frequencies are mediated by electric dipole transitions, strong optical-frequency magnetic dipoles do exist. In fact, we see magnetic dipole emission every day from the many lanthanide ions (such as erbium, europium, and terbium) that help to illuminate everything from fluorescent lighting to telecom fiber amplifiers. Higher-order processes such as magnetic dipole and electric quadrupole transitions also play an important part in the light emission from transition metal ions and semiconductor quantum dots. Nevertheless, most applications have overlooked the device implications of these electric-dipole-forbidden transitions throughout the visible and near-infrared regime, and their contributions to many important emitters have not been fully characterized.In this presentation, we will experimentally characterize the "forbidden" transitions in a range of solid-state emitters and investigate their applications and implications for nanophotonics. We will examine the electric dipole approximation commonly used to describe light-matter interactions and discuss naturally occurring systems that exhibit higher-order magnetic dipole and electric quadrupole emission. We will illustrate how these nanoscale quantum transitions can provide both a new way to probe magnetic light-matter interactions and a new degree of design freedom for active electronic and photonic devices. Specifically, we will demonstrate how the different symmetries of multipolar transitions can be exploited to identify, quantify, and control light emission, even at sub-lifetime scales. Despite similar radiation patterns, magnetic and electric dipole emitters have different symmetries with respect to polarization and phase. Thus, in an inhomogeneous environment, we can tailor interference effects and the local density of optical states to selectively enhance either electric or magnetic dipole emission [1,2]. To examine the scope of such higher-order transitions, we will present quantum mechanical calculations that identify all the magnetic dipole and electric quadrupole emission lines in the trivalent lanthanide series in the visible to near-infrared spectrum [3]. Then, we will present an energyand momentum-resolved spectroscopy technique to directly quantify the electric and magnetic dipole contributions from any mixed transition. [4] Using energy-momentum spectroscopy, we will experimentally examine the higher order transitions in lanthanide ions [4,5], transition metal ions [6], and epitaxial quantum dots [7]. If time permits, we will then show how the symmetry differences between magnetic and electric dipoles can be used to address specific electronic states [6] and to dynamically tune emission spectra at sub-lifetime-scales [8].

Magnet system for the KEKB main ring

For four pigeons key-peck responding was reinforced on a variable-interval reinforcement schedule in the presence of a vertical white line. When response rates had stabilized a horizontal white line was introduced, in the presence of which reinforcement was not available (extinction). The horizontal line was presented once per session, immediately before the vertical line was presented. The duration of the horizontal line varied randomly from session to session, being either 0 sec (i.e., no presentation), 10 sec, 30 sec, 2 min, 10 min, 40 min, or 120 min. When the horizontal line was present for more than 0 sec, behavioral contrast was obtained in the presence of the following vertical line. Contrast increased with increasing durations of the horizontal line, asymptoting when the horizontal line was present for 40 min.

This study explored the mechanisms that underlie asymmetries for the horizontal vertical illusion (HVI), which deceives length perception, so that a vertical line is perceived as longer than a horizontal line of equivalent length. In Experiment 1, university students (n=14) made length judgements for vertical and horizontal lines. The vertical line was shifted in eight steps from the far left of the horizontal line (⌊) to the far right (⌋). An HVI was observed for the medial positions (⊥), which diminished towards the lateral positions. The HVI was also stronger when the vertical line was on the left. Because the left/right asymmetry changed as a function of lateral/medial position, the asymmetry within the HVI stimulus is most likely the result of pseudoneglect, which affects judgements of horizontal length. In Experiment 2, participants (n=15) made judgements for HVI stimuli presented to the left- and right-hemispace and the midline. The HVI was stronger in the left hemispace. Because the asymmetry between the left- and right-hemispaces did not interact with the asymmetry within the stimuli, it was concluded that the asymmetry between hemispatial positions was the result of right hemisphere susceptibility to illusory geometrical effects whereas the asymmetry within the stimulus is related to an object-centred attentional asymmetry. The HVI is affected by asymmetries in length judgements and susceptibility to illusions and may provide interesting insights into attentional disorders in clinical populations, such as neglect.

Visuospatial biases in preschool children: Evidence from line bisection in three-dimensional space

The axial injection system of the SIN injector cyclotron: II. Description and experiments

PURPOSE. Previous experiments reveal that color-motion misbinding occurs in the periphery when central and peripheral objects share the same color, but move in opposite directions (Wu et al., 2004): The perceived illusory direction of peripheral objects is the same as the physical direction of central objects. This study tested whether color is necessary to elicit the illusory motion direction in the periphery, or whether shape-motion misbinding occurs without color. METHODS. The stimulus had moving objects in a central visual region and in adjacent peripheral regions. The objects were 0.3 deg long lines, half oriented vertically and half horizontally. In the central region, vertical lines moved in one vertical direction (say, upward) and horizontal lines in the opposite direction (downward). In peripheral regions, horizontal and vertical lines moved in the opposite directions (say, vertical lines moved downward, horizontal lines upward). All of the objects were either achromatic (metameric to EES 'white') or, in separate sessions, chromatic. In the chromatic condition, vertical lines were (say) red and horizontal lines green. In both conditions, observers fixated on a small cross in the center and judged the direction of motion of vertical lines in the periphery during a 20-second trial. The proportion of time with peripheral illusory motion in the chromatic condition was compared with the proportion in the achromatic condition. RESULTS & DISCUSSION. The proportion of time with illusory motion, and thus feature-binding errors, was greater in the achromatic condition than the chromatic condition (p<0.01 for each of three observers). Although introducing color increased the number of shared features between central and peripheral objects, feature misbinding was more likely without color. This shows that color is not necessary for motion misbinding, and that shape-motion misbinding in the periphery is at least as common as color-motion misbinding. Meeting abstract presented at VSS 2014

Horizontal bright lines are analyzed using high-speed photography. Although the shutter speed is set to the scan period, multiple scan buslines emit light. This is because the scan voltage is simultaneously applied to the multiple scan buslines. Therefore, the horizontal lines seem to be caused by short circuits between neighboring cathode electrodes, which are simultaneously used for the scan buslines. Vertical bright lines are also analyzed using high-speed photography. The vertical lines emit light when the corresponding scan buslines are selected. This is because the signal voltage applied to the vertical lines becomes higher. Therefore, the vertical lines seem to be caused by short circuits between anode electrodes and cathode electrodes in OLED pixels. Although the occurrence mechanisms of the horizontal lines and vertical lines may be different for each panel, it is found that the high-speed photography is a useful and interesting to analyze defects in passive-matrix OLEDs.

CORR Synthesis: When Should the Orthopaedic Surgeon Use Artificial Intelligence, Machine Learning, and Deep Learning?

The Neural Basis of Vertical and Horizontal Line Bisection Judgments: An fMRI Study of Normal Volunteers

The JHF 50-GeV Synchrotron, a high intensity proton synchrotron, consists of 96 bending magnets, 176 quadrupole magnets and 48 sextupole magnets. The design study of the magnets is now in progress. Also, the conceptual design study of the power supply system has been started. The bending magnet is of a modified window frame type, 6.2 m in length and 1.8 T in magnetic field in peak. The field gradient of the quadrupole magnet is 20 T/m in peak and the bore radius is 66 mm. The total active power of bending and quadrupole magnets is estimated to be 80 MW in peak. Recent results of the design studies of magnets and power supply system are described in this paper.

A nanoantenna is a nanodevice that manipulates light propagation and enhances light-matter interaction at the nanoscale. Integration of an emitter into a nanoantenna capable of increasing local density of photonic states at the emission wavelength results in the enhanced spontaneous emission rate (Purcell effect). The most widely studied nanoantennas for the Purcell enhancement are plasmonic nanoantennas made from gold or silver nanostructures supporting surface plasmon resonances. In most cases, nanoantennas have been used for the enhancement of electric dipole-allowed transition of a molecule. In addition, recently, nanoantennas capable of enhancing magnetic dipole transition of a molecule are attracting attention. For the magnetic Purcell enhancement, nanoantennas have to have magnetic resonances at the optical frequency. Although it is possible to achieve magnetic resonances at the optical frequency by plasmonic nanostructures, the inherent absorption loss of noble metals limits the magnetic Purcell enhancement. On the other hand, nanoparticles of high refractive index dielectrics inherently have low-loss magnetic-type Mie resonances at the optical frequency, and thus are potentially more attractive as a material to realize large magnetic Purcell enhancement.We have developed spherical nanoparticles of crystalline silicon (Si) having the magnetic dipole (MD) and quadrupole (MQ) Mie resonances at the optical frequency [1]. In this work, to demonstrate the potential of a Si nanoparticle as a nanoantenna for the magnetic Purcell enhancement, we develop a composite nanoparticle, that is, a Si nanosphere decorated with europium ion (Eu3+) complexes, in which magnetic dipole emission of Eu3+ is efficiently coupled to the magnetic Mie modes of the nanosphere [2]. We systematically investigate the light scattering and photoluminescence spectra of the coupled system by means of single particle spectroscopy. The results are shown in Figure 1. By tuning the MQ Mie resonance of a Si nanosphere to the 5D0-7F1 magnetic dipole transition of Eu3+, the branching ratio between the magnetic and electric dipole (5D0-7F2) transitions is enhanced up to 7 times. The observed large magnetic Purcell enhancement offers an opportunity to develop novel fluorophores with enhanced magnetic dipole emission. Furthermore, the enhanced magnetic field of dielectric Mie resonators enhances otherwise very weak absorption due to magnetic dipole transition, and makes direct excitation of triplet states of a molecule possible [3]. Direct excitation of triplet states reduces photon energy necessary for energy conversion and chemical reactions utilizing a triplet state compared to a conventional process involving singlet-singlet excitation and singlet-triplet intersystem crossing.[1] H. Sugimoto, et. al., "Mie Resonator Color Inks of Monodispersed and Perfectly Spherical Crystalline Silicon Nanoparticles" Advanced Optical Materials, 8 (2020) 2000033.[2] H. Sugimoto, and Minoru Fujii, "Magnetic Purcell Enhancement by Magnetic Quadrupole Resonance of Dielectric Nanosphere Antenna", ACS Photonics, 8 (2021) 1794.[3] H. Sugimoto, et. al., "Direct Excitation of Triplet State of Molecule by Enhanced Magnetic Field of Dielectric Metasurfaces", Small, 2021, DOI: 10.1002/smll.202104458.Figure 1: Photoluminescence (red curves) and scattering (black curves) spectra of single Si naosphere-Eu3+ complex composite nanoparticles with different Si nanosphere diameters. The diameters are shown at the right end of the figure. Figure 1