Michael Bieler edited sectionCURRENT_STATU.tex  over 8 years ago

Commit id: 2b09002c2238491e30e8e4b1d01a246eeed93c68

deletions | additions      

       

A survey on failure analysis in 2008 for nine light sources~\footnote{Survey participants for the failure analysis questionnaire came from: APS, ESRF, SPring-8, Diamond, SOLEIL, BESSY II, Elettra, ANKA and SLS.} revealed significant differences for the calculation of beam availability~\cite{L_deke_2009}.  In the following we summarise the main findings of the survey.  In many cases the beam availability calculations were determined by identifying events as ``downtime'' that interrupted data taking for  the majority of the users. Some facilities considered ``long'' injector outages - causing ``decaying beam'' operation - to be downtime, others accounted for these events individually.  Most facilities only counted beam delivery between two outages if it exceeded a minimum duration.   The minimal required duration varied between 15 and 60 minutes.  

If a particular failure mode is identified to be more frequent at some facilities,   then this provides an incentive for a common project to develop more reliable solutions.   As a consequence of everyone using the same common metrics, a fairer comparison may also  emerge when requesting funding to from  supranational authorities.