T. Kawano

Y. Narushima

National Institute for Fusion Science (NIFS-Repository)

§l. Report of Operational Results of an Access Control System Developed for LHD Controlled Area Kawano, T., Narushima, Y. We started practical use of the access-control system at the same time when the plasma experiment using the largc helical dcvice (LHD) was started. Afterwards, we have had several years experience of operating the system. Based on the experience obtained at the point of respective years, we improved the system year and year. After these improvements, the system is preferably developcd, although some problems we have to settle in the future are remained yet. Tn .the following,· we intend to summarize recent operational results. Table 1 shows the access frequencies as operational results obtained from 1999 to 2002. The term of "access" means a pair of entrance and exit the LHD controlled area in this study. In Table I an annual sum totals of access frequency were from 9000 to 15000 around 12000 times, and averages of the access frequency a day were also from 110 to 150 around 130 times. The maximum access frequency a day of these four years was 611 times observed in 2001. Table I Access frequency Fiscal year Annual sum Avera~e Maximum Total' (per ay) (per day) 1999 12260 114 486 2000 10193 132 452 2001 15305 154 611 2002 9167 124 372 Because a plasma experiment was carried out over the autumn or the winter from the summer recent four years, thc LHD controlled area was set up in the same period and the access control system was operated to monitor human going in and out the LHD controlled area. We examined all the personnel access data during these years and could summarize as shown in Figs. 1,2, and 3. In Fig.l, a numeral shown along X-axis shows progress days from the experiment start and the access frequency in each day is plotted as a function of the progress days. Similarly, Figs.2 and 3 show distribution of access frequency in every day of weck and that in every time (hour) of day. As read from Fig.l, the access frequency was as a whole less than 200 times a day, although some data were larger than 300 timcs, espccially those data recorded in 30-50 progress days of 200 I (plotted by open circle). We examined an experiment performed in those days 200 I, and found that some trouble had happed with vacuum. The access data in Fig.1 reflect the experimental situation that many workers frequently entered and exited the LHD controlled area for maintenance of recovering the trouble. In 448 Fig. 2, we can see dependence of access frequency on day of week. At the beginning and the end of week (Sun, Mon and Sat), low access frequency is observcd. In the contrariety this, the higher access frequency is seen for middle three days of week (Tue, Wed and Thu). This means that active plasma experiments were carried out and most frequent access arose on the middle three days. Figure 3 shows dependence of access frequency on time of day, and clarifies the tendency that high frequent access was done at both time zones corresponding to the beginning and the end of an experiment. More than 50% of access in a day was done around both the time zones. These accesses might be recorded by preparation and after-adjustment works for experiments in the time zones. 700 600 ~ 600 0 • it 400 ~ 300 m 8 200 ~ 100 0 0 Fig.l 4500 4000 ?; 3500 0 ~ 3000 g 2500 ~ 2000 • 8 1500 0 1000 < 61999 02000 10 20 30 40 50 80 70 80 90 100 110 Progress day Access frequency in each progress day from experiment start. A 1999 02000 02001 0 <> 2002 0 0 0 & 0 0 0 0 500 r--f-B ~ 0 0 Sot Sun Mon Tu. W.d Thu Fri s.t Day of he week Fig.2 Dependence of access frequency on day of week 2500 ~ 2000 o • 6- 1500 ~ ::l 1000 • o ~ 500 o o o t999 • 02000 o200t~--------------~gr---~ 02002 • o 2 4 6 8 10 12 14 18 18 20 22 24 Time of the day Fig.3 Dependence of access frequency on time of day 

Report of Operational Results of an Access Control System Developed for LHD Controlled Area

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