Andreas Luedeke edited sectionPROPOSED_SECO.tex  about 9 years ago

Commit id: 66ec896782ca6b801ab5912578cc55165b3b3c31

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{\em ALBA:} is continuously monitoring the electron transverse beam size with a pinhole that uses the X-rays part of the synchrotron radiation produced in a bending magnet.   The image is visually controlled in real time at the control room and automatically recorded on the ALBA database. Nominal beam sizes at the monitor are 60\,\mu m 60\,$\mu m$  in horizontal and 30$\,\mu m$ in vertical. Any deviation from the usual beam size by more than 20\% in any transversal plane is registered as a beam incidence and the beamlines are informed about it.  

{\em SLS:} does not have an on-line bunch purity measurement available.   We measure our filling pattern measured by the means of an avalanche photo-diode and a fast ADC.  Alarms are set for a deviation of single bucket charge from the nominal by more than 1$\,nC$. 1\,nC.  The nominal charge in the bunch train is about 1$\,nC$, 1\,nC,  alarms are raised at bunch charges of 0 or above 2$\,nC$. 2\,nC.  Those events are currently very rare and not covered by the automatic operation event recording.  A new, more precise digitiser will be implemented beginning of 2015.   With that device we plan to define tighter alarm limits and use the automatic operation event recording. 

\begin{table}  \centering  \caption{Distorted-filling \caption{\label{table:filling_limits}Distorted-filling  limits for different facilities\label{table:filling_limits}} facilities}  \begin{ruledtabular}  \begin{tabular}{lrp{3.75cm}}\hline  \textbf{Facility}&\parbox[t]{2.25cm}{\textbf{Bunch charge deviation}}&\textbf{Remark}\\[3.5mm]\hline 

E.g. if less than one hour is between two beam trips then the time in-between is counted as downtime.   This can be defined as an extra failure mode: 'short-user-time'.   The limit of what time is too short for user experiments depends on the time the facility needs to get into thermal equilibrium and on the typical length of a measurement at an experiment.   Each facility should define this cutoff time limit $T_{\mbox{short-user-time}}$; $ T_{\mbox{short-user-time}}$;  it may depend on the operation mode. {\em ALBA:} considers 'Short-user-time' as 'no-beam' events if the interval between beam delivery and trip is less than about 30 minutes; although at the moment there is no official number for this short-user-time but a common sense rule is used. 

in yearly statistics to the public.  \begin{table}  \centering  \caption{Schedule \caption{\label{table:sf_limits}Schedule  accounting at different facilities\label{table:sf_limits}} facilities}  \scriptsize  \begin{ruledtabular}  \begin{tabular}{lp{1.1cm}p{1.2cm}p{1.5cm}p{1.5cm}p{1.2cm}}\hline