g2n Analysis Meeting
Xiaofeng Zhu discussed the g2n analysis
progress:
- The second
run through the offline analysis has begun
- The ntuples
have been converted to root files
- False asymmetry
study:
-
Corrected the scalar trigger fro runs 2496-2562
-
Problem in the synchronization of the scalar and event clocks.
Some first scalar
events are missing. So far, by checking the
scalar event
and scalar history file, they are the same
-
Will check the scalar clock Vs. 1 MHz clock to see if the
scalar
clock is fine
- Studied PID cut dependence
Xiaofeng will look at:
Cut dependence
on geometry, beam position, and beam ramping
Kevin Kramer discussed his progress
on the target analysis:
- Within a
week Kevin plans on finishing:
-
Collecting measurements for the cells
-
Writing the tech-note
-
Analyzing the RTD's by averaging over the target chamber
-
Analyzing the temperature studies
-
Calculating the pressure for all the cells
- Measured the physical dimensions of the cells:
-
Measured with a Caliper
-
Noted that there is an error ~ 3% for the vertical diameter
of the pumping
chamber
-
Archimedes volume measurement agrees with UVA with
an offset of 0.6
to 0.8 mL (0.5% error)
- Window and wall thickness measurements
-
UVA and JLab's measurements match very well (2% uncertainty)
-
16 good wall measurements on most cells
-
Need to get the window from Tilghman to measure thickness
- Internal chamber volumes determined by using a combination
of
Archimedes, water cell, mechanical, and
optical measurements
- Internal pumping chamber temperature from the temperature
tests
have ~ 5% uncertainty
Kevin's long-range targer analysis plans
include:
- Cell flux
analysis: November and December
- Water NMR
analysis: December and January
Wolfgang Korsch gave a report on his
EPR analysis:
- Refit all
data
- Defined
"spin flip time" and checked a few runs: No significant difference
- Studied
AFP losses:
-
Shapiro: -0.140% +/- 0.03%
-
VA1: -0.621% +/- 0.05%
-
VA1: -0.420% +/- 0.09%
-
Note: Cell was in two different positions and the gradient
coil was on
- Calculated P_t by using analytical solution of the diffusion
equation
- Assigned a P_t value to each run by using interpolation:
linear fit
to +/- 2 closest EPR measurements
- Checked the ratio of polynomial to spline fitting:
no significant difference
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