Hayashi, N. Machine Stability Analysis by Pulse Based Data Archiver of the J-PARC RCS JACoW Geneva, Switzerland 978-3-95450-176-2 10.18429/JACoW-IBIC2015-TUPB026 English 381-385 TUPB026 ion ion-source linac operation feedback Contribution to a conference proceedings 2016 2016-01 http://dx.doi.org/10.18429/JACoW-IBIC2015-TUPB026 http://accelconf.web.cern.ch/AccelConf/IBIC2015/papers/tupb026.pdf The J-PARC RCS (Rapid-Cycling proton Synchrotron) runs with repetition rate of 25 Hz. The beam intensity of current monitors and beam loss monitors (BLM) data are archived for all pulses and they could be analyzed to study the machine stability. In addition BPM data are also recorded in regularly (2 seconds with every minutes) and particularly in case of the RCS MPS, the last several hundreds BPM data are recorded. We will report a few examples, in the case of magnet feedback problem or vacuum problem, how the BPM or BLM behaves.