Yasufumi Susuki

type:Article 本研究は,「GIGAスクール構想」の実現のために「ソフト」面に焦点をあて,デジタル教科書ならではの学びの充実をはかり,将来の学習者用デジタル教科書の有効な利活用も視野に入れつつ,現在配布されている指導者用デジタル教科書を用いた数学と理科の大学及び附属校の授業での利活用を含めたICTを効果的に活用する学習活動や教材化のための素案及び指導者用デジタル教科書を用いた授業実践の分析・考察を行うことを目的とする。 The purposes of this study are the following two points: (1) To focus on the soft wear aspects in order to realize the GIGA school concept and to enhance the learning that only digital textbooks can provide. (2) To analyze and discuss learning activities and teaching materials that effectively utilize ICT, including the use of digital textbooks for teachers in mathematics and science classes at universities and attached schools, as well as classroom practices using digital textbooks for teachers.

真空層内で加熱しているアルカリハライドの表面温度を，仮説に基づいて，熱電対で測定した。結果的に接触熱抵抗が働き，測定値の誤差は±５K以下にはならなかったが，熱電対を張り付けるための貼り付け剤の厚さに対する依存性など有益な情報が得られた。

To observe specular oscillations in ion-surface scattering originating from layer-by-layer desorption of an electron stimulated desorbed (ESD) surface, a 15 keV proton beam was impinged on the surface with an angle of incidence less than 1°. We prepared an experimental system to examine the scattering yields of reflecting protons by conveniently employing a fluorescent screen to view scattering yields (scattering patterns) and a commercial digital camera for yield measurements. Because the present energy of the proton beam was too low to illuminate the screen, a micro-channel plate was inserted in front of the screen. Measurements with electron irradiation show obvious damping specular oscillations the widths of angular distributions of scattered protons simultaneously oscillated with increasing electron fluence. From the measured periods of the oscillations, the ESD rates of thermal desorption from KBr(001) at 1.5 keV electrons irradiation were obtained for sample temperatures.

The surface morphology of KBr (001) irradiated by electrons is observed by first decorating the surface with Au particles and then replicating it with C foils. For the electron irradiation and the subsequent decoration, we integrated an electron-beam gun and a vacuum evaporator. The sample surface was irradiated by a 1.5 keV electron beam small Au particles were then evaporated onto the surface. Although the decorated sample was prepared in an ultra-high vacuum condition, the C foil was evaporated in a separate high-vacuum evaporator. To avoid deliquescence of the sample surface, contact between the sample and the ambient air was minimized by transporting the sample between the two vacuum chambers in a N2-gas-filled enclosure. Imaging the surface with a transmission electron microscope revealed many rectangular monolayer pits. The mean area of the pits and the associated standard deviation are presented versus temperature the mean pit area increases with temperature.

We introduce our handmade image intensifer for visualizing the beam profiles of accelerated ion beams having energy and current in the order of keV and nano-amperes, respectively. The simple image intensifer comprising stainless steel meshes and a fluorescent screen has been designed for the transport of mm-size ion beams. The intensifer is easy to install in the beamline of a vacuum setup, because it is designed to attach on a conflat flange of ICF70. We have used the image intensifer to observe the beam profiles of the ion beams transported from the ion source to an ultra-high vacuum chamber. Through the use of the image intensifer, bright images were obtained, and it was concluded that the intensifer is useful for observing the profiles of the beams having current densities greater than 0.1 nA mm-2.

Growth forms of Au particles prepared by vacuum evaporation methods on KBr(001) and KCl(001) substrates with two types of surface steps prepared by thermal sublimation and by electron stimulated desorption are studied by using a carbon backing method with a transmission electron microscope. Spiral steps of monoatomic height have been prepared on the substrate surfaces by heat sublimation. Epitaxial Au particles with pyramidal shapes and other multiply twined particles are grown by the vacuum evaporation on the substrates at temperatures of 50-450°C. The size distributions of the particles on the substrates are reported and the typical size is measured to be smaller than 20×20 nm2. The ratio of populations of the multiply twined particles along the KBr steps is increased compared with that on the flat area. However, this increase in the ratio is not observed for particles grown on KCl. Additionally, step assemblies are prepared by electron stimulated desorption (ESD). The dependence of the size distributions of the Au particles grown on the substrates on electron Influence is measured for the ESD surfaces. With increasing electron Influence, the peak particle distribution size becomes smaller and particles smaller than 1 nm are observed.

We have examined the surface-channeling of 550 keV protons on electron-bombarded KBr(001) surfaces at grazing incidence. On the surface, electron-stimulated desorption (ESD) resulting from the irradiation of 5 keV electrons changes the surface morphology. In order to investigate the change of the surface morphology, the luminous intensity distributions observed on a fluorescent screen (scattering patterns) of the reflected protons under the surface-channeling conditions are measured. Normalized specular intensity of the protons oscillates, and the results of computer simulations show that the period of the intensity oscillation agrees with the period of layer-by-layer desorption. The measured period of the oscillation is comparable to the simulated one, i.e., the period of the desorption, however, the measured amplitude of the oscillation is weak. This shows that the layer-by-layer desorption of the experimental surface is observed but is not as remarkable as that of the perfect surface introduced in the simulation. (C) 2013 Elsevier B.V. All rights reserved.

Trajectories of fast (0.55 MeV) protons impinging under planar surface channeling conditions with an angle of incidence of several mrad are calculated on KBr(001) surfaces decorated by electron stimulated desorption (ESD). Two-dimensional angular distributions of protons scattered on the surface are obtained. In order to calculate trajectories, a computational technique is needed to form a set of morphologies of the surfaces according to the electron ‰uence. In our method, an assumption is made that the topmost atoms on the low coordinate sites are easily emitted by the ESD processes5). By choosing parameters introduced in the method, the oscillatory behavior of the desorption yields demonstrated by other groups is reproduced2). The resulting peak intensity of the re‰ected protons from the trajectory on the ensemble of surfaces with varying electron ‰uence oscillates as the electron ‰uence increases. Corresponding angular distributions of re‰ected protons have been measured on the electron irradiated KBr(001) surfaces, and a similar oscillation can be seen on the scattered yields with weak amplitudes.

Surface-channeling at grazing incidence of 550 keV protons on electron-bombarded KCl(001) and KBr(001) surfaces is investigated. In order to derive step density of the surfaces as a proportional function of electron-fluence lying in a range below 3×10 15 cm -2, intensity distributions (scattering patterns) of reflected protons on a fluorescent screen are observed. With increasing the fluence, the scattering patterns shift to lower scattering angle. The peak-angles of the luminous intensity are compared with calculated results of computer simulations. For both KCl and KBr surfaces, the electron fluence of 1.0×10 15 cm -2 is equivalent to the density of monolayer steps of 1.3×10 5 cm -1 piled upon in the simulation. Copyright © 2002 - 2012 Hogrefe Publishing.

To demonstrate experimental evidence caused by the lattice strain that was induced by the surface steps introduced by electronic stimulated desorption of ionic-crystals, the ion scattering experiment has been performed. Surface-channeling of protons incident with 5 mrad on an electron-irradiated KBr(001) surface is investigated using a 0.55 MeV beam of protons. The direction of the incident beam is adjusted along the &lt 100&gt channeling condition and the channeling-dips of the scattering yields are observed. The electron dose-dependence of the minimum yields (χmin) and widths of the dips (φ1/2) are compared with those measured on a KCl (001) surface. For the results of the χmin and φ1/2, results of KBr and KCl show similar dependence on the irradiation dose. For the both surfaces, two small peaks appear in symmetric positions on the channeling-dips. Peak-separations between the two peaks and widths of the peaks increase with the irradiation dose. Although no difference of the lattice strain induced on the two surfaces is detected only by the present experimental results, slight difference between the results for the two surfaces is observed and it is expected to be related with experimental evidence to demonstrate the lattice strain.

Angle-dependent energy losses of well-collimated 5-10 keV protons scattered in collisions with CH4, CH6, and C3H8 molecules have been measured. The thickness of the targets is less than 20mPa.m, which is determined from the measured neutral fraction in the scattered beam and the charge-transfer cross sections reported by another group. The scattered protons have slightly expanded tails of the angular distribution. The measured energy losses increase with the angle. The stopping cross sections, which are obtained by integrating the angle-dependent energy losses over the square of the angle, agree well with the compilation values of SRIM-2006. The stopping cross sections are found to have a non-linear relationship with the size of target molecules. The contribution of a carbon atom attached by two hydrogen atoms of a heavier molecule becomes relatively small. This molecular size effect is enhanced with the decreasing energy of protons. Meanwhile, for protons that are deflected significantly, the molecular size effect is decreased.

To understand the various surface morphology of ionic crystal that is irradiated by electrons, the surface channeling technique of ion beam is used. The energy spectra and the channeling-dips are measured by the detection of 550 keV proton beam scattered from the electron-irradiated surface of KCl(001). After the electron-irradiation, the roughness of the sample surface is observed by an Atomic force microscope. The results of these experiments are compared with the calculated results of a computer simulation. The proton beam which directed along the 〈100〉 axis penetrates into the crystal and is scattered at large angle. This result is due to the surface morphology changed by the electron-stimlated-desorption.

Energy loss spectra and angular distributions of 610 keV protons scattered on the (001) surfaces of the ion crystals are measured. The angle of incidence of protons is smaller than 13 mrad. The surfaces have been in-situ irradiated uniformly and the other nonuniformly so that its upstream side for the incident protons is removed preferentially. The surface damages created by the irradiation are observed by an atomic force microscopy (AFM) in air. With increasing the irradiation dose, the energy losses and the peak angles of scattering of the scattered protons are plotted. The results depend largely on the distribution of damages, and are compared with calculated results by a computer simulation. It is found that the change of the angular distributions depends not only on the distribution of damages but also on the angle of incidence of protons to the surface.

A method to develop teaching materials for physics is studied by challenging their practical uses. The teaching materials made are demonstrated in our hand-made science museum and they are revised by summarizing evaluations from students, children and parents. A teaching material is considered to take its position in a classroom teaching applying official school-internship. Educational effect of the material is examined. The method applying the school-internship is effective for developping a teaching material, because revision of a classroom teaching and rapid understanding of the children's response are available. The method tried here is also effective for propagation of physics. Additionally, it is expected that the students, who take part in this work, are grown to be excellent teachers.

Generally, the "wave" treated in the senior high-school physics is difficult for students. A teaching material for learning the wave has been prepared. For the wavesource, a small magnet placed on an electro-magnet whose current is supplied by an AC 100 V line is used. The vibration of the small magnet is propagated on a stressed string and the standing wave on the string is observed. The angle between the string and the direction of given vibration can be changed during the observation. Since the parts are compactly placed on a painted wood plate, the teaching material becomes easy to use for students and easy to prepare for teachers.

Rolling table for balls of pinball' has been made for student's experiment of dynamics and for demonstration to school children. The table is made from a 2-meter'curtain rod and wood plates. The velocity (Vm>2m/s) of the ball is measured with the time of flight method (TOF) on the table. The ball is ejected from the end of the table and the trajectory length of the emitted ball has been measured. The collision dynamics of the balls has also been demonstrated. In these measurements, the kinetic energy is compared under the principle of conservation of mechanical energy. The momentum transfer in a collision is compared under the low of conservation of momentum. The results show that the phenomena ignored in traditional teaching material can be seen in the carefully measured data. It is concluded that the present teaching material is useful to guide undergraduate, high school and elementary school students, to consider dynamics with suitable choice of use in the teaching.

A teaching material for study of Boyle-Charles' law has been prepared for student's experiment. The amount of the gas molecules (i.e., air) inside a vessel is changed by an injector. The pressure and temperature of the air in the vessel are measured by a water gauge and thermometer, respectively. They are also measured by corresponding sensors connected with the "Science Workshop". This teaching material has been used practically by several students in a high school and several students in our university. By observing their experiments, it is concluded that this material is useful for the education of the university students. Since the teaching materials for thermodynamics concerning gas molecules are rarely used compared with those for other fields of physics, we discuss to what the students having studied with this apparatus can extend their teaching in a class-room.

Neutral fractions are measured for (0.4-0.8) MeV H+ ion beams transmitted through aluminum epitaxial foils under the (100) planar channeling condition. Two foils are prepared: the first (Theta=90degrees) is almost perpendicular to the direction of the beam and the second (Theta=30degrees) is inclined at 60degrees compared with the first. The measured neutral fractions, which are in the 10(-3) range, exhibit a minimum at the (100) channeling direction, however, the channeling effect is enhanced for the foil with Theta=30degrees. The fraction is calculated for the two foils from the equilibrium fraction and the charge exchange between the ions and the surface atoms in a vacuum. Both the equilibrium fraction and the charge exchange depend on the exit positions of ions from the midplane of the channel. The measured energy dependence of the ratio (channeling/random) of the fractions is reproduced by calculation. Thus the results indicate that the transmitted charge-state distributions are modified by the charge exchange after the emergence of ions in a vacuum.

Neutral fractions are measured for ions transmitted parallel to the beam direction at the incidence of (0.3-0.6) MeV H+ beams on a poly-crystalline aluminum foil with a variance in the angle of incidence theta. The fraction measured for the equivalent ion-energy decreases with the decreasing angle of incidence. The relative difference between the fractions at the normal (theta = 90degrees) and inclined (theta = 30degrees) incidence increases slightly with the increasing energy of the ions. The dependence of fraction on the angle is calculated by using a model for the charge-exchange that includes not only the electron loss from and electron capture into the 1s state of hydrogen, but also the electron loss after an excitation of hydrogen in collisions with the atoms on the topmost layer of the surface. The electron loss of the excited hydrogen enhances the decrease of the fraction at the inclined incidence and this improves the calculated results to reproduce the experimental one.

Dependence of the neutral fractions contained in the foil-transmitted 0.6 MeV H+ ion beams on the angle of incidence (2.5-90 degree) has been measured at the beam direction: when (0.6-1) MeV H+ ions are impinged on a poly-crystalline Al thin foil. The fraction for ions of the same exit-energy decreases slightly with the decreasing angle of incidence. The dependence on the angle of incidence is calculated with a classical model for charge-exchanges with a modification taking into account the topological effect of the exit-surface of the foil. The surface is observed by a three-dimensional-profile microscope and the parameters of the surface roughness are obtained. The observed parameters are consistent with those calculated from the surface topology assumed to obtain the neutral fractions comparable to the measured ones.

Energy losses of fragment protons from 0.2- and 0.5-MeV/amu H-2(+) were measured at transmission through amorphous carbon foils of thickness less than 25 mu g/cm(2). The energy losses of randomly oriented fragment protons and those of the fragment protons aligned in the direction of motion show how the spatial correlation of the protons affects the energy loss. We use the dielectric formalism to calculate the stopping power of amorphous carbon for two spatially correlated protons and compare with the experimental energy-loss data. We conclude that higher energies or thinner foils are necessary to understand the anomalous energy loss of aligned proton pairs.

Neutral fractions of specularly reflected beams have been measured for the glancing-angle incidence of (0.2-0.5) MeV H+ ions on a clean (001) surface of SnTe. The measured fractions have been compared with the results calculated by a classical model for charge exchanges and by a model based on the first-order perturbation theory. The experimental and calculated results have differed greatly. The disagreements are attributed to collisions with valence electrons on the surface. The electron capture cross-sections of (0.2-0.5) MeV H+ ions for valence electrons have been derived, based on the measured neutral fraction and distribution of valence electrons for jellium background positive charges, and are found to be about ten times larger than those for the outermost electrons of Sn and Te atoms calculated by the classical model.

Samples of Ti and Zr metals have been carbonized or nitrided at high temperature by means of reactive plasma processing. Thickness and hardness of modified layers increased with the processing temperature and time in an experimental range below 1500 degrees C for less 5h. The maximum hardness of TiC-layer modified at 1300 degrees C for 3h was about 5000Hv(kg/mm(2)) and the maximum thickness of ZrC-layer formed at 1400 degrees C for 5h reached about 100 mu m. A TiC-layer was analyzed with EPMP, XRD, EXAFS and PAS(Positron Annihilation Spectroscopy), It was confirmed that the sub-surface layer of Ti metal was the mixture of TiC ceramics and Ti metal, and that the thickness of TiC with NaCl type structure was very large.

The attenuation of hydrogen atoms and H-like He, Li, C and O ions of about 10-MeV/amu due to the electron loss collisions in thin carbon foils was measured as a function of foil thickness. At the thinner foil region, the incident beams attenuated exponentially as the foil thickness increased. From the attenuation rates, we have determined the electron loss cross sections of the ground slate H-like ions. The obtained cross sections are larger than the theoretical predictions based on the Born approximation, especially for projectiles of higher atomic number. They can be well explained quantitatively taking account of the contribution from the projectile excitation which leads to the ionization by the subsequent collision in the foils. (C) 1998 Published by Elsevier Science B.V.

The total secondary electron emission yields from a clean (001) surface of SnTe crystal are studied at the bombardment of hydrogen clusters (H+, H-2(+) and H-3(+) ions) with energies ranging from 7 to 12 keV/amu. The observed yield is not proportional to the number of protons in the cluster ion. The yields are successfully explained by applying the stopping powers of a homogeneous electron gas for the constituents of the clusters in keV energy region, which provide the vicinage effect.

Energy losses of H+ fragments repelled parallel and antiparallel to the beam direction at dissociation are measured for a glancing-angle incidence of 0.15-0.6-MeV/amu H-2(+) ions on a clean (001) surface of SnTe. The sum of the energy losses of the specularly reflected fragments is larger than twice that of protons of the same velocity reflected from the surface. For the interpretation of the vicinage effect on the stopping power of the surface, the energy losses of the pairs of fragments resulting from the dissociation of H-2(+) are calculated at the glancing-angle scattering. The contribution of single-electron excitation to the energy-loss of the pair is calculated with the harmonic-oscillator model [J. Basbas and R. H. Ritchie, Phys. Rev. A 25, 1943 (1982)] and that of collective excitation by the superposition of surface wakes of two protons. A dependence of the vicinage effect on the distance from the surface is found from the calculated stopping powers-where the pronounced effect becomes weak as the distance decreases. The calculated energy losses of the reflected pairs of protons agree fairly with those measured. The agreement of the calculated energy losses with those measured supports the calculated dependence of the vicinage effects.

Mean energy losses of 31.8 MeV neutral He-3 atoms penetrating through thin carbon foils of 1.6-7.2 mu g/cm(2) were measured using a high-resolution magnetic spectrograph. The measured particles are those entered into the carbon foil as He-3(0) and emerged from it as He-3(0). From the attenuation measurement of He-3(0) in the foils, we can regard the measured energy losses as those of He-3(0) in a frozen charge stare. The measured stopping power of carbon for 31.8 MeV He-3(0) is 58.2 +/- 4.9 eV/mu g/cm(2). Including our previous data for other partially clothed ions of the same velocity, the projectile atomic number dependence of the screening effect due to the bound electrons is roughly reproduced by the theoretical predictions based on the Born approximation. (C) 1997 Elsevier Science B.V.

Mean energy losses of 10.4-MeV neutral hydrogen atoms penetrated through thin carbon foils of 3.7-13.4 mu g/cm(2) were measured using a high-resolution magnetic spectrograph. The measured particles are those entered into the carbon foil as H-0 and emerged from it as H-0. From the attenuation measurement of H-0 in the foils, we can regard the energy losses as those of H-0 in a frozen charge state. The measured stopping power of carbon for 10.4-MeV H-0 is 21.3+/-1.8 eV/(mu g/cm(2)) and is about one-half that for H+ at the same speed. This result agrees well with the theoretical predictions based on the first-order Born approximation.