Skip to content

ITS#

General considerations#

If any of the plots listed on this page remains empty during a run, please call the ITS on-call. The only exception, i.e., where empty means good quality, is for the four plots on the lane status.

Quality summary#

its_summary its_summary The left panel summarises all ITS QC checks for the last QC cycle. The top line gives aggregated quality status with the text message suggesting actions for the QC shifter.

  • Quality: BAD: contact ITS on-call expert
  • Quality: Medium: create a log entry
  • Quality: NULL: the plots are empty. Check in DCS if ITS is in STANBY. If not, inform the ITS on-call.

In BAD or MEDIUM cases, this canvas will duplicate the error message from the QC plot in the form "Flag: Unknown: ERROR MESSAGE". The bottom line shows an example of BAD status in Track Angular distribution and MEDIUM in nClusterPerTrack plots.

The right panel provides a time trend of the ITS QC summary. If ITS quality is BAD for the whole run duration, ITS should be tagged as BAD in the logbook.

Error count vs Error id#

[QC on FLP]its_pb1

The total number of decoding errors (the error ID is on the x-axis). The left figure provides an example of a good case, while the right corresponds to run with BAD quality;

The BAD quality flag will be triggered when a number of decoding errors exceed some limit; MEDIUM quality corresponds to the case when the number of errors is non-zero, but not significant for the BAD run. The following quality messages can be printed on the plot:

  • Quality::GOOD
  • Quality:: BAD: "definition of error ID"
  • Quality:: MEDIUM: "definition of error ID"

If the number of error with a certain ID show a BAD quality message, call the ITS on-call. In case of the MEDIUM quality, create a log entry linked to run and with tag = ITS. Please note that entries in the last bin are not an issue, because this bin is not related to any detector problems.

Please ignore the last bin of this plot. The increase of counts there should be neglected.

Fake-hit rate overview#

[QC on FLP]its_pb2_new Overview of the averaged fake-hit rate value for each ITS stave (given by triangles). The fake-hit rate value is displayed with the colored scale in hits/events/pixels. The left plot provides an example of a GOOD plot, and the right figure is an example of a BAD quality plot.

The following quality messages can be printed on the plot:

  • Quality::GOOD
  • Quality:: Medium: Max occupancy over 10^{-6}
  • Quality:: BAD: Max occupancy over 10^{-5}
  • Quality:: BAD: There are staves without hits

In case of BAD quality messages or empty triangles (some might stay empty for the first 25-30 mins of a run, do not call in this case), please call the ITS on-call.

Trigger count vs TriggerID and FeeID#

[QC on FLP]its_pb4 Plot summarizing trigger flags. The X-axis corresponds to the ID of Front-End Electronic; the Y-axis shows the list of all possible triggers that can be received by FEE. The coloured scale represents the counts in each bin. During physical run, we expect that all FEEs receive HB, ORBIT, SOC and TF trigger signals. The GOOD run is shown on the left panel, while the problematic one is depicted on the right. QC can plot the following error messages:

  • Quality::GOOD
  • Quality:: BAD: Trigger flag (TRIGGER_NAME) of bad quality

Call the ITS on-call in the case of BAD quality messages and also in the following cases:

  • there are x-bins without entries (i.e., vertical white lines on the plot)
  • entries are present in the empty lines in the example plot above.
  • the plot is completely empty

Lane Status Flag: ERROR/FAULT/WARNING#

[QC on FLP]its_pb5

This plot indicates the faction of lanes (colored axis) in ERROR/FAULT/WARNING status for each ITS stave. The empty plot corresponds to the GOOD run quality (left plot); in other cases (right plot), the following quality messages can appear on the plot:

  • Quality:: MEDIUM: ML/OL have staves in ERROR
  • Quality:: MEDIUM: Inner Barrel has stave with >2 chips in ERROR/FAULT/WARNING
  • Quality:: BAD: Layer 0/1/2/3/4/5/6 has >25% staves with lanes/chips in ERROR/FAULT/WARNING

If the BAD quality message is printed, call the ITS on-call.

Lane Status Global#

[QC on FLP]its_pb8

This plot shows the fraction of lanes into ERROR, FAULT, and WARNING statuses. The TOTAL bin gives the total fraction of lanes in any not OK status. The BAD quality will be triggered when the bin value exceeds the 10% threshold.

The following Quality messages can appear:

  • Quality::GOOD
  • Quality::BAD: >10% of the lanes are bad.

In case of BAD quality messages call the ITS on-call.

ITS Misconfiguration plot#

[QC on FLP]its_pb8

This plot shows the estimated readout rate for each FEE component of the ITS. Note that each FEE should have the same estimated frequency, as it is shown in the example figure.

The following Quality messages can appear:

  • Quality::GOOD
  • Quality::BAD: MISCONFIGURATION. CALL EXPERTS.

In case of BAD quality messages call the ITS on-call. Additionally, compare the estimated ITS readout rate with the ITS readout rate from the DCS shifter: these numbers should be the same, otherwise, call the ITS on-call.

Cluster Occupancy overview#

[QC on EPN]its_pb8

Overview of the cluster occupancy, i.e., number of clusters per event, for each stave (1 bin in the plot). The left figure gives example of the GOOD run, while on the right is the problematic distribution. Check the general trend, i.e. occupancy decreasing when going from the innermost to the outermost layers. This MO can have the following quality messages:

  • Quality:: MEDIUM: Layer_Stave has large cluster occupancy
  • Quality:: BAD: Layer_Stave has empty stave

Call the ITS on-call in case of anomalies in the plot or if the BAD quality message will appear.

Fraction of empty lanes#

[QC on EPN]its_pb8

This figure provides the fraction of empty lanes (without clusters) per IB/OL/ML/Total. When any of the bins exceeds the 10% limit, you will be notified with the Quality:: BAD: message. Please, call the ITS on-call in this case.

Angular Distribution#

[QC on EPN]its_pb8 its_pbtemp

Angular distribution of online reconstructed ITS tracks as a function of phi vs. eta (2D plot).
Possible Quality messages that can appear on the plot during a run:

  • Quality::GOOD: plot might still be bad! See example above and look at the arrows in the plot.
  • BAD: Asymmetric Phi distribution (OK if there are disabled ITS sectors)
  • BAD: Asymmetric Eta distribution (OK if there are disabled ITS sectors)
  • BAD: NO ITS TRACKS

Please try to reconfigure the detector (set run type again) in case the quality is BAD or if the plot shows several holes (blue regions in between the yellow parts as shown in the plot above), call ITS on-call is the issue persists. Please call the ITS on-call also if the plot remains empty during the run.

Number of clusters per track#

[QC on EPN]its_pb9

Distribution of the number of clusters per track. The plot shows a GOOD example of pp collisions run. The following messages can appear:

  • Quality::GOOD
  • Quality::Medium Mean is outside 5.2-6.2, ignore for COSMICS and TECHNICALS
  • Quality::BAD: 0 tracks with 4/5/6/7 clusters (OK if it's synthetic run)
  • Quality::BAD: NO ITS TRACKS

Call the ITS on-call in case of BAD quality messages, if a completely different plot is obtained, or if the plot stays empty after 5 min of data taking. In case of MEDIUM status, create log-book entry.