Compton γ-ray sources have been in operation for over 30 years with new facilities being under construction or proposed. The gamma beam system under implementation at the Extreme Light Infrastructure ...- Nuclear Physics facility in Romania will deliver brilliant γ-ray beams with energies up to 19.5 MeV. Several instruments for measuring the parameters of the γ-ray beam are under development at ELI-NP. One of these instruments based on a High Purity Germanium detector is routinely used for beam energy measurements at other facilities. Here we investigate the use of a High Purity Germanium detector to continuously monitor the intensity of the ELI-NP gamma beam by measuring the inelastic scattering of photons. This method relies on both experimental and simulated data and it has been successfully tested during a recent experiment at the High Intensity γ-ray Source facility.
To evaluate the clinical utility of the meniscal extrusion transverse ratio of the medial meniscus in the diagnosis of meniscal root tear compared with the gold standard of arthroscopic diagnosis.
...This retrospective study sample included 32 males and 35 females who underwent MRI at our institution. There were 24 meniscal root tear cases. The control groups were 18 cases of medial meniscal tears without root tears and 25 cases of negative meniscal findings on arthroscopy. Meniscal extrusion (L) and maximal transverse lengths (T) of the medial meniscus were measured, and L/T ratios were calculated. These results were correlated with arthroscopic findings and analysed statistically. With arthroscopic findings used as the standard of reference, the sensitivity and specificity of 10%, 11% and 12% extrusion thresholds, and 3 mm of medial meniscal extrusion (MME) as diagnostic thresholds, were calculated.
The mean length of the meniscal extrusions of meniscal root tears was twice as long as the control group. The mean L/T ratio of the meniscal root tears was approximately 13%, while those of the control groups were 5%. The differences in the L and L/T between the meniscal root tears and normal and meniscal root tears and other meniscal tears were statistically significant (p<0.001), but those between normal and other meniscal tears were not. The best diagnostic discrimination was achieved using an extrusion ratio threshold of 10% (79% sensitivity, 86% specificity). The 3 mm of MME threshold demonstrated high specificity (98%), but not high sensitivity (54%).
The mean L/T ratio of the meniscal root tears was approximately 13% and was statistically significant. The best diagnostic discrimination was achieved using an extrusion ratio threshold of 10%. Advances in knowledge The use of the L/T ratio in combination with MME can be a useful method for evaluating medial meniscal root tears.
In-vessel components of the Korea Superconducting Tokamak Advanced Research (KSTAR) were developed for 2010 campaign to provide a crucial circumstance for achieving the strongly shaped and diverted ...plasma. Moreover, the in-vessel components such as limiter, divertor, passive stabilizer, in-vessel control coil (IVCC) system demonstrated good performances satisfying the original design concepts. In addition to the plasma facing components and the IVCC, in-vessel cryo-pump (IVCP) system was also installed to leverage divertor operation. Besides the in-vessel components, there have been substantial progresses in development of the heating and current drive system. The KSTAR heating and current drive system includes all kinds of the major heating systems such as neutral beam injection (NBI), ion cyclotron range of frequency (ICRF), electron cyclotron resonance heating and current drive (ECH and ECCD), lower hybrid current drive (LHCD) systems. As an initial stage for full equipment of the heating systems to total power of 26
MW, several key systems such as 1st NBI (called NBI-1), ICRF, and ECH-assisted startup system successfully demonstrated their excellent feasibilities in the design and performances for dedication to the 2010 campaign.
Studies on nuclear astrophysics, nuclear structure, and other interests have been performed using the radioactive-isotope (RI) beams at the low-energy RI beam separator CRIB, operated by Center for ...Nuclear Study (CNS), the University of Tokyo. The elastic resonant scattering is a striking tool to study astrophysical reactions and nuclear clusters. In particular, when it is coupled with a thick target and inverse kinematics, the measurement can be very efficient and even feasible with RI beams. By measuring resonant scattering, we can study the properties of resonant states which could play an important role in the astrophysical reaction, or have an exotic nuclear structure. The 10Be+α elastic scattering has been measured at CRIB, and three resonances which are in agreement with the prediction of a linear-chain structure by Suhara-En'yo were observed, giving a strong indication of the existence of such an exotic structure. Measurements based on the indirect technique of the reaction measurement, such as the Trojan horse method, have also been performed at CRIB.
In the response to the demand for electrical energy, much effort aimed to develop and commercialize high temperature superconducting (HTS) power equipments has been made around the world. In Korea, ...companies and universities are developing a power distribution and transmission class HTS transformer that is one of the 21st century superconducting frontier projects. The composite winding of transmission class HTS transformer is concentrically arranged primary winding (High)-Secondary winding (Low)-tertiary winding (High) from center. Primary winding is continuous disk type, Secondary winding is layer type and tertiary winding is Double pancake type. For the development of transmission HTS transformer with composite winding, the cryogenic insulation technology should be established. We have been analyzed insulation composition and investigated electrical characteristics such as breakdown of , barrier, kapton films and surface flashover on Fiber Reinforced Plastic (FRP) in Liquid nitrogen . We are going to compare with measured each value and apply the value to most suitable insulating design of the HTS transformer.
Stability Analysis of the KSTAR PF Busline Park, Y. M.; Lee, H. J.; Chu, Y. ...
IEEE transactions on applied superconductivity,
06/2012, Volume:
22, Issue:
3
Journal Article, Conference Proceeding
Peer reviewed
The Cable-In-Conduit Conductor (CICC) for the KSTAR buslines is made of NbTi superconducting (SC) strands. A busline consists of several electrical joints, which are the major heat load contributors ...to the busline cryo-system. In the poloidal field (PF) busline helium circuit, the supercritical helium is fed to the electrical joint of current lead end and comes out to the magnet terminal joint. This helium flow configuration has been verified to maintain the cryogenic stability of the buslines through the KSTAR operation. During the normal operation of the KSTAR PF coil, the heated helium coming out to both the coil and the busline meets at the magnet terminal and exchange heat, but the busline outlet temperature still remained less than magnet outlet temperature. As the buslines for the electrical connection in series of the upper and lower coils for PF1 and PF2 have the helium path through the two terminal joints of magnet, they experience higher temperature than the other buslines mainly due to the larger heat exchange. In this case, the connection buslines are considered to have very low safety margin and have the strong possibility of quenches.
Abstract
The dynamics of a nuclear open quantum system could be revealed in the correlations between the breakup fragments of halo nuclei. The breakup mechanism of a proton halo nuclear system is of ...particular interest as the Coulomb polarization may play an important role, which, however, remains an open question. Here we use a highly efficient silicon detector array and measure the correlations between the breakup fragments of
8
B incident on
120
Sn at near-barrier energies. The energy and angular correlations can be explained by a fully quantum mechanical method based on the state-of-the-art continuum discretized coupled channel calculations. The results indicate that, compared to the neutron halo nucleus
6
He,
8
B presents distinctive reaction dynamics: the dominance of the elastic breakup. This breakup occurs mainly via the short-lived continuum states, almost exhausts the
7
Be yield, indicating the effect of Coulomb polarization on the proton halo state. The correlation information reveals that the prompt breakup mechanism dominates, occurring predominantly on the outgoing trajectory. We also show that, as a large environment, the continuum of
8
B breakup may not significantly influence elastic scattering and complete fusion.
A position-sensitive ionization chamber has been constructed and commissioned at the Physics Department of Sungkyunkwan University to extract position information on incident charged particles for ...future nuclear reaction measurements. By utilizing the newly-designed position-sensitive anodes and the previously-commissioned portable gas-filled ionization chamber by Chae
et al.
, position information on incident particles could be obtained. The device was tested with an
241
Am α-emitting source, and the standard deviation of the fitted Gaussian distribution was measured to be 1.76 mm when a collimator with a 2 mm hole was used.
Alpha resonant scattering is a simple and promising method to study α-cluster structure in nuclei. It has several good features which enable us to perform measurements with short-lived and relatively ...low-intense RI beams. Several measurements on alpha resonant scattering have been carried out at CRIB (CNS Radioactive Ion Beam separator), which is a low-energy RI beam separator at Center for Nuclear Study (CNS) of the University of Tokyo. Recent α resonant scattering studies at CRIB, using7Li,7Be and10Be beams with a helium gas target, are discussed.
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