2003-2004 Operation:

Sampling and control systems were revised for long-pulse operation

I System modifications in 2003:

• Fast sampling (Max. 500kHz) divertor probe system was developed for 18 channel probe array.

I-1) Divertor probe operation modes can be selected:

• (1) V-scan-mode for Isat, Te, Vf (normally used),
  (2) I_s-mode for fast Isat change measurement,
  (3) V_f-mode for fast Vf change measurement,

I-2) Fast sampling and Fast V-scan are available compared to old sampling system:

• For normal 15s discharge, 25kHz sampling/100Hz V-scan are used to cover 10s.
  (Max. 4) fast-sampling time windows (e.g. 100kHz sampling/500Hz V-scan) are available to measure transient events such as ELM and detachment,
  Here, system consists of two type of recorders (see figure below), (1) KS4020 (Max. 500kHz, 12bit) and (2) KS4008 (Max. 132kHz, 16bit).
  Sampling time is limited by the specifications.

I-3) System works for Normal (15s)- and Long (65s)-pulse operations of JT-60U.

II Performance of Hardware and Software are limited by the following factors:

• Only one probe array (18ch) was replaced in 2003 summer VV work (other probes are eroded and several probes has problems of electrical isolation from VV.)
  -> Operation plan: V_f-mode is selected if no request.
  Limited number of data are processed during shot interval (~23min).
  256k data/channel is sampled in routine operations.

III Operation of old sampling system (18 channel array, 1kHz sampling/10Hz V-scan) stopped mostly due to digitizer&multiplexer problems.

Arrangement of transient recorders and power amp. for 18 probes.

Data server information and PIDs for DAISY(2003-2004)

Memo (2004/2):
Tentative problem to be solved.
(1) Start trigger did not work every 5-6 shots in NB heating.
(2) Capacity of PS (5A) for Inner divertor was not enough in high power heating and high density plasma.
    -> numbers of PS should be increased.

Data server information and PIDs for DAISY (before 2002)