MRD Brief Summary¶
Layers (Z position) - # of paddles (type of paddles)
V1 (z3): 15-15= 30 paddles (old KTeV paddles, 15 cm wide)
V2 (z5): 17-17= 34 paddles (old KTeV paddles, 15 cm wide)
V3 (z7): 13-13= 26 paddles (SciBooNE paddles, 20 cm wide)
V4 (z9): 15-15 = 30 paddles (SciBooNE paddles, 20 cm wide)
V5 (z11): 15-15 = 30 paddles (SciBooNE paddles, 20 cm wide)
H1-H6 (z2, z4, z6, z8, z10, z12): 13-13 = 26 paddles (SciBooNE paddles, 20 cm wide)
In total of 306 channels: 150 paddles on Vertical layers + 156 paddles on Horizontal layers.
Only 26 of those paddles have Positive PMTs (Horizontal Layer# 4, Position z8) and the rest, 280 paddles have Negative PMTs on them.
z0 and z1 layers are our Front Muon Veto (FMV) layers in the WCSim package. A couple of PMTs on the MRD have cables labeled as z0 and z1, but those are only the cable labels (spares from the old SciBooNE time!).
MRD Electronics Setup¶
MRD data is recorded by a setup of discriminators and TDCs which are located in two CAMAC crates in racks 7 and 8 at ANNIE hall. There are 6 TDCs and 12 discriminators in each CAMAC crate, and one TDC is always surrounded by two discriminators. The channel labeling scheme is 0-based for the TDCs (Channels 0-31) and 1-based for the discriminators (Channels 1-32). (TDC_DISC_Setup.png, tdc_ribbon_fixes_fixed.png)
Data is taken in COMMON STOP mode, i.e. the trigger signal marks the end of the recorded event. One TDC tick marks a time frame of 4ns and is calculated with respect to the trigger signal. In COMMON STOP mode, this means that a larger TDC value refers to an earlier point in time.There are two main trigger types for the MRD:
- The beam trigger, which is issued by the arrival of a RWM signal by the Central Trigger Card (CTC).
- The MRD cosmic trigger, which is issued when both the first and last layer of the MRD register a coincident hit.
The cosmic trigger signal is also routed through the CTC in order to give priority to beam trigger signals in case of coincident beam and cosmic triggers. There are two designated loopback TDC channels that register hits to distinguish the trigger types: The first loopback channel is channel 15 in TDC crate 7, slot 11 and represents triggers from the CTC, while the second loopback channel is channel 14 in TDC crate 7, slot 11 and represents cosmic triggers.
The signals of the PMTs of a few MRD paddles are amplified before passing the discriminator. The following table gives an overview of the TDC locations and occupancies and shows which channels are being amplified.
Slot 2, Channel 0-12, Channel 16-28
Slot 5, Channel 0-12, Channel 16-28
Slot 8, Channel 0-12, Channel 16-28
Slot 11, Channel 0-12, Channel 16-28
Slot 18, Channel 0-12, Channel 16-28
Slot 21, Channel 0-12, Channel 16-28
Slot 2, Channel 0-12, Channel 16-28 (FMV channels, amplified)
Slot 5, Channel 0-14, Channel 16-30
Slot 8, Channel 0-31
Slot 11, Channel 1-13, Channel 16-31 (amplified)
Slot 14, Channel 0-6, Channel 8-11, Channel 13-30 (amplified)
Slot 17, Channel 0-30 (amplified)
On the software side, each paddle is represented by a unique channelkey. The channelkey mapping is defined within the ToolAnalysis repository in the file configfiles/LoadGeometry/FullMRDGeometry.csv . The attached plots show the distribution of channelkeys in a top and side view of the MRD. (SideView_MRD_paddles_Chankey.png, TopView_MRD_paddles_Chankey.png)