Pi0 Meeting No.11: Beam energy determination
I have resumed my beam energy analysis. In the past I had problems with
the DB that I was using in my analysis. After I discovered this problem I
changed the DB and started my analysis again. First I analyzed Ta data, which
due to the large atomic mass of Ta represent the "cleanest" set of data. This
analysis was done last October. Last week I analyzed Hydrogen data. I used
the same procedure as for the Ta and got fairly good results. This week I
successfully analyzed Carbon data.
Tantalum results :
Tantalum measurements - My table
E0 = 1192.55 MeV +/- 0.06 MeV
Hydrogen Runs & Results :
Run #2360:
Run #2885:
Run #3135:
Run #4392 (problematic run on the edge of the acceptance):
Run #4646:
Run #4674:
Run #4757:
Results:
Hydrogen measurements - My table
E0 = 1192.06 MeV +/- 0.03 MeV
Carbon Runs & Results :
Run #2357:
Run #2640:
Run #2641:
Runs #2730 + #2731 + #2732:
Run #2733:
Run #2734:
Run #2884:
Run #3272:
Run #3511:
Run #3590:
Run #3672:
Runs #4111 + #4112 + #4113:
Run #4114:
Run #4389:
Run #4391:
Run #4518:
Carbon Results:
E0(Elastic) = 1192.64 MeV +/- 0.06 MeV
E0(1st Excited) = 1192.56 MeV +/- 0.06 MeV
Mean result:
When we calculate the mean value of the beam energy determined from Ta and H data, we get following
results:
Emean = (1192.29 +\- 0.23) MeV = 1192.29(1+/- 2.0E-4)
Remark:
In this calculation I considered most probable energy losses for Ta and H targets:
Target | Eloss [MeV]
=======|============
H | 1.7 MeV
Ta | 0.35 MeV
C | 0.47 MeV
I should also stress that the statistical error of the results (mean value of the deltas) is very small ( of order
0.06MeV) Therefore I considered in my beam energy fitting procedure only systematical error, which comes from the
transformation of the NMR measurements of the magnetic field to the central momentum of the spectrometer and is of
order 0.6 MeV.
To-Do:
1.) Do the analysis for the C and Al data.
2.) Reconsider the energy-loss calculation.
Last modified on 03/08/10
