Results from the run 39247

1. General Information

2. OCDB files

The OCDB files that were used for the reconstruction of this run were produced by the SSD DA during the pedestal run with the number 39090. The plots below show the map of the bad channels:

3. Analysis of clusters

Here are some histograms obtained with the official offline QA for the SSD clusters. In all plots we see the accumulated statistics from all the events of this run. There was a selection on the golden clusters.

Number of clusters per event per layer

Module number with clusters

Local coordinates x-y-z

Global coordinates x-y-z

Cluster type - Charge ratio - Cluster charge

Cluster charge (P-Side) - Cluster charge (N-Side) - qN/qP

Cluster charge map - Cluster charge correlation

-- PanosChristakoglou - 17 Jun 2008

Addendum 3 Sept

Searching for noise/low charge peak

Now let's try to look into the low-Q peak based on this data. I took the reconstructed data from the grid (PASS2, aliroot v4-13-06).

Zooming in on the module distribution on layer 5:

Two clear peaks are visible. So let's have a look at the highest one, module 1106.

Local xz SSD recpoints run 39247, module 1106:

Most clusters are located in a small range in local x (around x=-2) and z. This suggests that this is due to a few noisy strips, which are somehow correlated between P and N side.

And cluster charge:

shows that most clusters have a low charge. This suggests that the low-Q clusters have something to do with the (correlated noise).

Next steps:

• Find strip numbers
• Look at noise, ADC distributions for those strips