Analysis of A-F special runs

1
Analysis of A-F special runs
S.Doulas, Shashi Dugad, Mike Eades, Anatoli
Efremov, Al Ito, B.Satyanarayana
2
Introduction

• Special runs were taken in order to obtain qADC
  and TDC distributions for each channel with
  sufficient statistics
• qADC distributions are meant to be used to
  compute invidual thresholds using q to V
  conversion factors (Presented by S.Dugad in an
  earlier Muon Meeting)

3
A-F geometry

• Consists of nine F rings 70 channels per ring
• Side and top octants (Octs. 04, 7) has full
  coverage of the F rings while the bottom octants
  (Octs. 5 6) have 50 coverage
• 10 scintillators/ring/oct for the top and the
  side and 5 for the bottom octants

4
Data taking

• Special runs were taken by Anatoli, Steve Al
  during Aug-Dec, 2002
• Modified version of SCINTEXAMINE (Mike Eades and
  Steve) is used to covert the raw data into
  rootuples containing scintillator hits for each
  event
• Data processed by Anatoli, Steve and Al.

5
Data set summary
6
Analysis

• ROOT-based utility was developed to analyse the
  data in rootuples
• QADC and TDC distribution data for individual
  channels studied
• Muon energy loss in scintillators is h dependent
• Data is clubed as per F rings

7
Analysis (Contd.)

• F Ring channel number convention

8
F Ring-wise TDC entries
Total entries obtained by counting hits within
-3tdcrms lt tdc lt 3tdcrms
Side boundaries marked
9
TDC peak distrubutions

• TDC peaks are expected to be around 0
• For most of the channels the peak values lie
  within G3ns
• Some channels show large deviations

10
Bad TDC distributions
11
List of bad TDC channels
Note Peaks set to -100 when TDC distrubutions
couldn't be fit.
12
Ring-wise hit distribution

• Valid TDC hist counted for all channels in each
  phi ring
• Outer rings show large hits
• Backscattered tracks?
• No well separated peaks seen for backscattered
  particles

13
F Ring-wise ADC plots
Histograms filled with ADC hits having intime
TDC (-3tdcrms lt tdc lt 3tdcrms)
14
h dependence of ADC peaks

• Energy loss in scintillator increases with h.
• ADC distribution plotted as per F ring.

15
ADC peaks within a ring

• Within a ring, ADC peaks are expected to be
  same.
• For F 0 ADC data was clubbed for all channel
  of an octant
• ADC peaks show consistenancy within G15

16
Summary and future plans

• h dependence of energy loss seen from the data
• 9 channels showed bad TDC distribution
• Large number of hits in outer rings needs to be
  understood
• Pedestals to be obtained using calib runs
• Pedestal subtracted ADC distributions to be
  obtained per ring per octant (clubbing 10
  channels)
• q to V conversion to be applied on these to
  derive discriminator thresholds