Masaaki Takashina

Evidence for an alpha cluster condensed state in 16O(alpha,alpha') at 400 MeV

Inelastic

Probing effect of tensor interactions in 16O via (p, d) reaction

\alpha

Respiratory monitoring with an acceleration sensor

scattering on 16O is studied at 400 MeV by using an ice target. Near the 4-alpha breakup threshold of 14.4 MeV, a broad peak is observed at an excitation energy of 13.6+/-0.2 MeV with a width of 0.6+/-0.2 MeV. The spin-parity is estimated to be 0+ from the momentum-transfer dependence. The observed width is significantly larger than those of the neighboring 0+ states indicating a state with a well-developed alpha cluster structure. The magnitude of the cross section is sensitive to the density distribution of the constituent alpha clusters. The observed cross section is consistent with the theoretical prediction for the alpha cluster condensed state characterized by its dilute density distribution with a large root-mean-square radius of about 4.3 fm.

Coulomb Breakup Reactions in Complex-Scaled Solutions of the Lippmann-Schwinger Equation

Abstract We have measured the 16O(p, d) reaction using 198-, 295- and 392-MeV proton beams to search for a direct evidence on an effect of the tensor interactions in light nucleus. Differential cross sections of the one-neutron transfer reaction populating the ground states and several low-lying excited states in 15O were measured. Comparing the ratios of the cross sections for each excited state to the one for the ground state over a wide range of momentum transfer, we found a marked enhancement of the ratio for the positive-parity state(s). The observation is consistent with large components of high-momentum neutrons in the initial ground-state configurations due to the tensor interactions.

Enhanced collectivity in 74Ni

Respiratory gating radiotherapy is used to irradiate a local area and to reduce normal tissue toxicity. There are certain methods for the detection of tumor motions, for example, using internal markers or an external respiration signal. However, because some of these respiratory monitoring systems require special or expensive equipment, respiratory monitoring can usually be performed only in limited facilities. In this study, the feasibility of using an acceleration sensor for respiratory monitoring was evaluated. The respiratory motion was represented by means of a platform and measured five times with the iPod touch® at 3, 4 and 5 s periods of five breathing cycles. For these three periods of the reference waveform, the absolute means ± standard deviation (SD) of displacement were 0.45 ± 0.34 mm, 0.33 ± 0.24 mm and 0.31 ± 0.23 mm, respectively. On the other hand, the corresponding absolute means ± SD for the periods were 0.04 ± 0.09 s, 0.04 ± 0.02 s and 0.06 ± 0.04 s. The accuracy of respiratory monitoring using the acceleration sensor was satisfactory in terms of the absolute means ± SD. Using the iPod touch® for respiratory monitoring does not need special equipment and makes respiratory monitoring easier. For these reasons, this system is a viable alternative to other respiratory monitoring systems.

Global optical potential for nucleus-nucleus systems from 50 MeV/u to 400 MeV/u

We propose a new method to describe three-body breakups of nuclei, in which the Lippmann-Schwinger equation is solved in combination with the complex scaling method. The complex-scaled solutions of the Lippmann-Schwinger equation (CSLS) enable us to treat boundary conditions of many-body open channels correctly and to describe a manybody breakup amplitude from the ground state. The Coulomb breakup cross section from the 6 He ground state into 4 He+n+n three-body decaying states as a function of the total excitation energy is calculated using CSLS, and the result well reproduces the experimental data. Furthermore, the two-dimensional energy distribution of the E1 transition strength is obtained and the importance of the 5 He(3/2 � ) resonance is confirmed. It is shown that CSLS is a promising method to investigate correlations of subsystems in three-body breakup reactions of weakly bound nuclei. Subject Index: 213, 221, 227

Can clinically relevant dose errors in patient anatomy be detected by gamma passing rate or modulation complexity score in volumetric-modulated arc therapy for intracranial tumors?

Abstract The neutron-rich nucleus 74Ni was studied with inverse-kinematics inelastic proton scattering using a 74Ni radioactive beam incident on a liquid hydrogen target at a center-of-mass energy of 80 MeV. From the measured de-excitation γ rays, the population of the first 2+ state was quantified. The angle-integrated excitation cross section was determined to be 14(4) mb. A deformation length of δ = 1.04 ( 16 ) fm was extracted in comparison with distorted wave theory, which suggests that the enhancement of collectivity established for 70Ni continues up to 74Ni. A comparison with results of shell model and quasi-particle random phase approximation calculations indicates that the magic character of Z = 28 or N = 50 is weakened in 74Ni.

Couch height–based patient setup for abdominal radiation therapy

We present a new global optical potential (GOP) for nucleus-nucleus systems, including neutron-rich and proton-rich isotopes, in the energy range of 50\char21{}400 MeV/u. The GOP is derived from the microscopic folding model with the complex

{sup 16}C inelastic scattering studied with the microscopic coupled-channels method

G

Assessment with cone-beam computed tomography of intrafractional motion and interfractional position changes of resectable and borderline resectable pancreatic tumours with implanted fiducial marker

-matrix interaction CEG07 and the global density presented by the S\~ao Paulo group. The folding model accounts for realistic complex optical potentials of nucleus-nucleus systems well and reproduces the existing elastic scattering data for stable heavy-ion projectiles at incident energies above 50 MeV/u. We then calculate the folding-model potentials (FMPs) for projectiles of even-even isotopes,