Summarize of Mapper Analysis

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Summarize of Mapper Analysis
Leo Aliaga
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Index

• Mapper Simulation and experimental test.
• Position Resolution from the simulation.
• Current Calibration
• Stability of the PMT
• Recent studies
• Future tasks

In all of these studies, We use Cs-137
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Mapper Simulation and experimental test
- We have written a code in Geant4 plus Root5.
(doc 1048 - 1057)
- The program save, basically, the energy
deposited in each strip
- We use Cs-137. the beta rays are encapsulated.
We have gamma rays with E661.7 KeV in 92 of
decays (doc 1078)

• Our simulations results has been tested again an
  experimental setup. (doc 1127)

- comparison between the normalized current in
the PMT and the normalized total energy deposited
in each strip.
Red experimental Blue simulation
We have a Gaudi version of the Mapper Simulation
(doc 1407-1465)
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Position Resolution from the simulation (doc 1465)
In principle, when we move the source 15
positions for the standard angle (40 degrees) of
the cone, we obtain from the full simulation
- We define the position resolution as
- And, We have taken into account the statistical
fluctuations in the spectral shape generating
several distributions in a simple C program
considering the results from the simulation and
uncertainties given by
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Results
The position resolution is improved when we have
more source positions
The position resolution is improved when we
enlarged the cone angle
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Current Calibration (doc 1423)
Pico-ammeter
M-64 in Box
FEB
FMP
Read out first 16 fibers with Cs-137 source for
13 different source positions and HV 800 V

• Module connectors 1 (first eight extrusions)
  and 2 (second eight extrusions)

• Weve taken
• - data with the Cs-137 source
• - pedestal data (without source)
• Pico-Ammeter to measure anode current in the
  PMT
• DAQ software measures the ADC spectrum from FEB
  and offline analysis in order to have the
  pedestal shift

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Fit each curve of current vs. source position
with the data from the pico-ammeter (basically
with Lorentzian peak) in order to know -
fiber positions - shapes of the energy
deposited
Anomalous signals
- Probably, Physically damaged in some fibers or
problem perhaps on FEB
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Current calibration Allows conversion from
shifted pedestal location to current on PMT
The scatter plot of PMT current vs. pedestal
shift shows linear relationship.

• The ratios
  are plotted vs. distance of source from nominal
  fiber position.
• p1 shows that the fit is almost flat with a good
  ch2/ndf
• - The ratios are around 0.35

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Stability of the DAQ (doc 1723)
1. Study long term stability of the DAQ leaving
HV on for a week. Took same data set each day
High Voltage Supply 1st, 2nd, 3rd days
785V 4th, 5th, 6th days 786V 7th and 8th
days 787V

• Possible explanations
• Instability of the HV voltage supply
• Effects of the Temperature

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2. Study of the drift of the DAQ in a Mapper
time line (10.5 h)
- Something is happening in this time scale
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Recent studies
Fractional error of the mean pedestal respect to
the number of events
- Each 20 K events take 120 sec approximately.
- The fractional error is always small
- The behavior is almost flat after 10 K events
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Scan of the strip in the upper plane and lower
plane
- 2 typical plots
- Ratio between amplitudes is about ¼. We need to
think about this
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Study of the attenuation length of the fiber
According to the Formula from Steven Manly
(Rochester meeting-June13)
- We have taken data along the strip
- We need to analyze this data o redo with more
carefully. - We need to compare with our full
optics simulation.
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Progress and Future tasks
- We need to find the position resolution from
the FMP test for the upper and lower plane and
compare with the results from the simulation
- We need to optimize the number of events that
we take with the DAQ
- We need to analyze the data for study the
attenuation length and compare with the results
of simulation
- We need to redo the Lead test in order to find
the effects of the lead in the module.