No abstract

Since the successful first plasma generation in the middle of 2008, three experimental campaigns were successfully made for the KSTAR device, accompanied with a necessary upgrade in the power supply, heating, wall-conditioning and diagnostic systems. KSTAR was operated with the toroidal magnetic field up to 3.6 T and the circular and shaped plasmas with current up to 700 kA and pulse length of 7 s, have been achieved with limited capacity of PF magnet power supplies. The mission of the KSTAR experimental program is to achieve steady-state operations with high performance plasmas relevant to ITER and future reactors. The first phase (2008–2012) of operation of KSTAR is dedicated to the development of operational capabilities for a super-conducting device with relatively short pulse. Development of start-up scenario for a super-conducting tokamak and the understanding of magnetic field errors on start-up are one of the important issues to be resolved. Some specific operation techniques for a super-conducting device are also developed and tested. The second harmonic pre-ionization with 84 and 110 GHz gyrotrons is an example. Various parameters have been scanned to optimize the pre-ionization. Another example is the ICRF wall conditioning (ICWC), which was routinely applied during the shot to shot interval. The plasma operation window has been extended in terms of plasma beta and stability boundary. The achievement of high confinement mode was made in the last campaign with the first neutral beam injector and good wall conditioning. Plasma control has been applied in shape and position control and now a preliminary kinetic control scheme is being applied including plasma current and density. Advanced control schemes will be developed and tested in future operations including active profiles, heating and current drives and control coil-driven magnetic perturbation.

The aim of the Korea superconducting tokamak advanced research (KSTAR) project is to develop a steady-state-capable advanced superconducting tokamak for establishing a scientific and technological basis for an attractive fusion reactor. Since the KSTAR mission includes the achievement of a steady-state-capable operation, the use of superconducting coils is an obvious choice for the magnet system. The KSTAR superconducting magnet system consists of 16 toroidal field (TF) and 14 poloidal field (PF) coils which include 8 central solenoid coils. Both the TF and PF coil systems use internally-cooled cable-in-conduit conductors (CICC). The TF coil system provides a magnetic field of 3.5 T at the plasma centre and the PF coil system provide a flux swing of 17 V s. The major achievement in the KSTAR magnet system development includes the development of CICC, a full size TF model coil, a background magnetic field generation coil system and the construction of a large scale superconducting magnet and the CICC test facility. TF and PF coils are at the stage of fabrication for the KSTAR completion in the year 2007.

Analysis of eye diseases of patients at Kasungu District Hospital in Malawi was made. Malawi is one of the poorest countries in the world and the health system faces a lot challenges in terms of resources. The study was, therefore, done to understand the burden and distribution of eye diseases in this resource-limited setting. A retrospective study was conducted by extracting data from data registers in the outpatient eye department for the period of May 2015 to June 2016. The data of the reported eye diseases analyzed with variables such as patient gender, eye disease type, patient age and times of the year. There was no association between eye diseases and gender nor with times of the year. However, it was noted that the commonest type of eye disease was conjunctivitis. And, there was strong association of some disease type with age, for example, conjunctivitis was common in young age group while cataract was common in the elderly. It was shown in this study that many of the eye diseases endemic in Africa do generally occur in this selected district as well. However, the analysis presents the possibility of reducing the incidences of many diseases by preventive measures and access to health facilities on time.

The KSTAR Central Solenoid Model Coils (CSMC), which are in the form of split coils with same dimension, have been tested. The CSMC were successfully charged up to 20 kA and down to zero with different ramp rates. Various pulse waveforms were applied to the CSMC to analyse the AC-loss characteristics of the coils. The measurement method was a gas-flow calorimetry. In this work, two types of waveforms, the DC-biased sinusoidal wave ( = 2, 4 kA;