Three-dimensional proton trajectory analyses and simulation of neutral particle transport in an ICRF heated long pulse discharge on the large helical device

A three-dimensional neutral particle transport simulation code is applied to identify a source of the hydrogen outgas in a LHD long pulse discharge by ICRF heating. Radiation collapse induced by uncontrollable plasma density rise terminated the long pulse discharge. Toroidally non-uniform increases in the Hα emission and divertor temperature were observed. A CCD camera detected local heating of a vertically installed divertor plate, which is consistent with the strike points of the trajectories of protons accelerated by ICRF waves. The neutral particle transport simulation with the proton trajectory analyses shows that outgas from the divertor plates heated by the protons is necessary for explaining the observed toroidal non-uniform distribution of the Hα emission in the long pulse discharge

Risk factors for incisional hernia according to different wound sites after open hepatectomy using combinations of vertical and horizontal incisions: A multicenter cohort study.

Background:Although several risk factors for incisional hernia after hepatectomy have been reported, their relationship to different wound sites has not been investigated. Therefore, this study aimed to examine the risk factors for incisional hernia according to various wound sites after hepatectomy.Methods:Patients from the Osaka Liver Surgery Study Group who underwent open hepatectomy using combinations of vertical and horizontal incisions (J-shaped incision, reversed L-shaped incision, reversed T-shaped incision, Mercedes incision) between January 2012 and December 2015 were included. Incisional hernia was defined as a hernia occurring within 3 y after surgery. Abdominal incisional hernia was classified into midline incisional hernia and transverse incisional hernia. The risk factors for each posthepatectomy incisional hernia type were identified.Results:A total of 1057 patients met the inclusion criteria. The overall posthepatectomy incisional hernia incidence rate was 5.9% (62 patients). In the multivariate analysis, the presence of diabetes mellitus and albumin levels <3.5 g/dL were identified as independent risk factors. Moreover, incidence rates of midline and transverse incisional hernias were 2.4% (25 patients), and 2.3% (24 patients), respectively. In multivariate analysis, the independent risk factor for transverse incisional hernia was the occurrence of superficial or deep incisional surgical site infection, and interrupted suturing for midline incisional hernia.Conclusions:Risk factors for incisional hernia after hepatectomy depend on the wound site. To prevent incisional hernia, running suture use might be better for midline wound closure. The prevention of postoperative wound infection is important for transverse wounds, under the presumption of preoperative nutrition and normoglycemia

Extension and its characteristics of ECRH plasma in the LHD

One of the main objectives of the LHD is to extend the plasma confinement database for helical systems and to demonstrate such extended plasma confinement properties to be sustained in steady state. Among the various plasma parameter regimes, the study of confinement properties in the collisionless regime is of particular importance. Electron cyclotron resonance heating (ECRH) has been extensively used for these confinement studies of the LHD plasma from the initial operation. The system optimizations including the modification of the transmission and antenna system are performed with the special emphasis on the local heating properties. As the result, central electron temperature of more than 10 keV with the electron density of 0.6 x 10$^{19}$ m$^{-3}$ is achieved near the magnetic axis. The electron temperature profile is characterized by a steep gradient similar to those of an internal transport barrier observed in tokamaks and stellarators. 168 GHz ECRH system demonstrated efficient heating at over the density more than 1.0 x 10$^{20}$ m$^{-3}$. CW ECRH system is successfully operated to sustain 756 s discharge.Comment: 12th International Congress on Plasma Physics, 25-29 October 2004, Nice (France

Forward photon energy spectrum at LHC 7 TeV p-p collisions measured by LHCf

Abstract The LHCf experiment is one of the LHC forward experiments. The aim is to measure the energy and the transverse momentum spectra of photons, neutrons and π 0 's at the very forward region (the pseudo-rapidity range of η > 8.4 ), which should be critical data to calibrate hadron interaction models used in the air shower simulations. LHCf successfully operated at s = 900 GeV and s = 7 TeV proton–proton collisions in 2009 and 2010. We present the first physics result, single photon energy spectra at s = 7 TeV proton–proton collisions and the pseudo-rapidity ranges of η > 10.94 and 8.81 η 8.9 . The obtained spectra were compared with the predictions by several hadron interaction models and the models do not reproduce the experimental results perfectly

High Energy Particle Measurements during Long Discharge in LHD

The spatial resolved energy spectra can be observed during a long discharge of NBI plasma bycontinuously scanning the neutral particle analyzer. In these discharges, the plasmas are initiated by the ECH heating, after that NBI#2 (Co-injection) sustains the plasma during 40-60 seconds. The scanned pitch angle is from 44 degrees to 74 degrees. The injected neutral beam (hydrogen) energy of NBI#2 is only 130 keV because the original ion source polarity is negative. The shape of spectra is almost similar from 44 degrees to 53 degrees. However the spectra from 55 degrees are strongly varied. It reflects the injection pitch angle of the beam according to the simulation (53 degrees ot R* = 3.75 m in simulation). The beam keeps the pitch angle at incidence until the beam energy becomes to the energy, which the pitch angle scattering is occurred by the energy loss due to the electron collision. The low flux region can be observed around 10-15 keV, which is 15 times of the electron temperature. The energy region may be equal to the energy at which the pitch angle scattering is occurred. At the energy, the particle is scattered by the collision with the plasma ions and some of particles may run away from the plasma because they have a possibility to enter the loss cone. According to the simulation, the loss cone can be expected at the 10 keV with the small angular dependence. The depth of the loss cone is deep at the small pitch angle. The hollow in the spectrum may be concluded to be the loss cone as the tendency is almost agreed with the experimental result