Readout electronics plots

The readout electronic channels monitoring algorithm analyses not decoded RAW data in the same format in which are written on disk from DAQ system. Histro-grams produced are segmented on coincidence matrix and channels.

Coincidence Matrix plots

The electronic channel profiles, timing and trigger road are organized in 63 sector logic groups. The plots of Figure 4.3 and4.4 represent few example. In Figure 4.3(a)the profile histograms show the channel count of a RPC layer of two adja-cent coincidence matrix for all the pads of the corresponding sector logic. As a

5There are 48 special RPC doublets positioned on 24 coil ribs which are readout by the adjacent station nearest to the IP and three quarter of them are identified as ‘doublet z’ 3 and one quarter as

‘doublet z’ 2.

general rule the pivot channel ijk=0 or 1 are plotted separately (32 channels) but the confirm channel ijk=2-3 or 4-5 are plotted together (64 channels) because this correspond how they are connected along the readout strip panels.

Channel correlation plot between the trigger channel (ijk=6) and any confirm channel are also produced (see Figure4.3(b)) separately for each coincidence ma-trix. Timing plot and correlation plots are put together in the same folder, because it is when both spatial and time coincidence between different layers are verified that the trigger fires.

The electronic channel time is displayed by histograms like in Figure 4.4(a) and4.4(b), where the electronic channel absolute time and the time relative to the average trigger time in LowPt phi view.

Channel+ (ijk-ijk_off)*32 +cm*32 +pad*64

SectorLogic44_Cma0_1_ijk0_Profiles^{Entries 38053} SectorLogic44_Cma0_1_ijk0_Profiles

(a) One layer readout channel profiles of two adjacent phi view CM’s.

0

(b) Scatter plot between confirm channel number and trigger channel number of the same CM.

Figure 4.3: Examples of RPC readout channels commissioning plots. Data are from calibration stream.

Readout overview plots

Overview plots relates to the ATLAS RPC trigger-readout quantities (see plots of Figure4.5).

The plot of Figure 4.5(a)shows the distribution of the number of fired electronic readout channel per event. The mean value of the distribution is large because a cosmic muon cross generally more than RPC sector and the number of RPC chan-nels fired is multiplied by overlaps between coincidence matrix and by “logical-OR” connection ofφ strips.

In order to evaluate how the fired readout channel are distributed into readout hardware objects the 1D plot of Figure 4.5(b) and the 2D plots of Figure 4.5(c)

Channel + 32 * ijk

SectorLogic44_Tower3Cma0_time_vs_channelEntries 27139 SectorLogic44_Tower3Cma0_time_vs_channel

(a) Time vs readout channel of a CM.

Channel + 32 * ijk

SectorLogic44_Tower3Cma0_(time-triggertime)_vs_channelEntries 27139 SectorLogic44_Tower3Cma0_(time-triggertime)_vs_channel

(b) Relative time w.r.t average RPC trig-ger time vs readout channel of a CM.

Figure 4.4: Examples of RPC readout channels commissioning plots in ‘RP-CLV1/Profiles/SectorLogic44’ folder: and ‘RPCLV1/TriggerRoad/SectorLogic44’ fold-ers. Data are from calibration stream.

and 4.5(d) count the total number of fired channel per Sector Logic, Pad and Coincidence Matrix. The two bi-dimensional histograms have on the X axis the sector logic and on the Y axis, respectively, the Pad number (from 0 to 7) and the Coincidence Matrix number shifted by eight times the Pad number.

The plots of Figure4.5(e)shows the distribution of the number of trigger hits per event separated for the two views. The are four of such a plots. Two plots, one shown in Figure 4.5(f), display the correlation between trigger hits in Eta and Phi view. Plots showing the correlation between Eta and Phi Coincidence Matrix trigger hits are also produced. These plots identify an area called Region of Interest (RoI).

RPC hit / event

rpclv1_hitperEvent Entries 6615184 Mean 106.9 RMS 34.78 rpclv1_hitperEvent

(a) Distribution of the number or fired read-out channels per event.

SLChannel_per_SectorLogic Entries 8.381274e+08

SLChannel_per_SectorLogic

(b) Sector logic hit profile plots.

1

PadChannel_per_SectorLogic Entries 8.381274e+08

PadChannel_per_SectorLogic

(c) Hit map of trigger tower vs sector logic.

1

CMChannel_per_SectorLogic Entries 8.381274e+08

CMChannel_per_SectorLogic

(d) Hit map of CM vs sector logic.

LowPt phi trigger hits / event

0 2 4 6 8 10 12 14

Trigger_Hits_LowPt_phi_Stat Entries 6615184 Mean 2.314 RMS 1.736 Trigger_Hits_LowPt_phi_Stat

(e) Distribution of LowPt trigger hits in phi view.

LowPt phi trigger hits / event

0 2 4 6 8 10 12 14

LowPt eta trigger hits / event

0

Trigger_Hits_Lowpt_etaphi_StatEntries 6615184 Trigger_Hits_Lowpt_etaphi_Stat

(f) Correlation between number of η and φ trigger hits in LowPt stations.

Figure 4.5: Examples of RPC readout channels overview plots in ‘RPCLV1/Overview’

folder. Data are from physics-RPCwBeam stream.

Four plots (figure 4.6(a)) shows the pattern of the coincidence matrix layers:

J0, J1, I0 and I1 associated to a trigger hit for the same Coincidence matrix. The majority logic is programmed into the CMA, therefore not all combinations are allowed.

Trigger Conditions: 0=Pivot0, 1=Pivot1, 2=LowPt0, 3=LowPt1

NoneL=0 L=1 L=0,1L=2 L=0,2L=1,2L=0,1,2L=3 L=0,3L=1,3L=0,1,3L=2,3L=0,2,3L=1,2,3L=0,1,2,3

Counts

103

104

105

106

107

Trigger_Condition_LowPt_Phi Entries 1.865404e+07

Trigger_Condition_LowPt_Phi

(a) Distribution of LowPt trigger pattern in φ view.

1 10 102

103

104

105

106

107

Sector Logic

0 10 20 30 40 50 60

1/4 Lpt 2/4 Lpt 3/4 Lpt 4/4 Lpt Lpt+0/2Hpt Lpt+1/2Hpt Lpt+2/2Hpt

TriggerCondition_vs_SectorLogicEntries 4.006922e+07

TriggerCondition_vs_SectorLogic

(b) Counts of trigger layers pattern vs sector logic.

Figure 4.6: Distributions of detector layers patterns generating LowPt φ trigger signals in coincidence matrix.

CM + Pad*8 + SL*56 500 1000 1500 2000 2500 3000 3500

No Hits

Figure 4.7: Distribution of trigger conditions for each single ATLAS RPC Coincidence Matrix (CM).

The 2D plot of Figure4.6(b)is similar to the previous ones. It shows for each Sector Logic which detector layer patterns generate the trigger in phi view. The plot is divided in two parts along the Y axis, the lower part is related to the LowPt trigger coincidence and the upper part to the HighPt trigger coincidence. LowPt and HighPt triggers are realized with four and two independent RPC active layers respectively. In standard configuration LowPt trigger logic consists of 3 out of 4 layers in the same trigger time window (25 nsec maximum) and HighPt trigger logic of 1 out of 2 layers, in addition to a LowPt trigger. Consequently, not allowed layers pattern giving trigger (such as 2 out of 4 layers in LowPt trigger) is evidence of some inefficiency in the readout or fake triggers. The are also 2D plot similar to the previous one but the trigger condition is monitored for each single Coincidence Matrix (figure4.7). On the X axis is listed the coincidence matrix number shifted by eight times the pad number and 56 times the sector logic number and on the Y axis is listed all possible layer combinations that could or could not provide a trigger hits.