Meeting minutes for first period
- Redo optic: include 1.1, 1.5 and 2.2 GeV optic data into optimization.
- Sieve simulation and data comparison can be found here.
- For same kinematic: scattering angle, momentum setting
but the sieve show up at focal plane differently. So in the optic, need
to add in P0 dependent term.
- For example, sieve pattern of 1.1 and 2.2 GeV at DP=-3% are different. The plot is here. 2.2 GeV tend to expand more in all directions.
- New optic optimize 155 data and 51 parameters (x: 14, y 15:, theta 10:, phi: 12).
- And new reconstructed angles: phi: 9 pars ,theta: 5 pars, y: 8 pars.
- Get elastic 12C cross section with new optic:
- Choose C&D holes for 1st and 2nd row. Cross section result for all energy can be found here.
- There is a problem with 1.1 GeV @ DP=2%.
- For 2.2 GeV, there is 27% correction from excited state.
- Get elastic 3He cross section with new optic:
- Result for 2.2 GeV hasn't corrected for quasi elastic contribution yet.
- Result for 1.1 and 1.5 GeV seem not agree so well between different beam energies. The trend should be the same.
- To do:
- What's wrong with 1.1 GeV @ DP=2%?
- For 3He elastic, which DP is bad? What is the general trend? This determine the acceptance due to extended target.
- Why W plot is not so good for new optic? Especially the low W (super elastic) part?
- Applied beamtrip cut to 1.1 GeV, DP=2%:
- Run 1888 (has 2/3 of time has no beam)--this is carbon run. With beamtrip cut, the result does not change.
- Use different carbon run, run 1889 (this run has several beam trips). With beam trip cut, result is the same as run 1888.
- From this plot. The spectra of phi_tg and theta_tg between simulation and data are different. Data loss more than simulation.
- To do:
- Need to put VDC efficient into the result.
- Results corrected for all efficiency as shown here.
- Carbon results look good. But there is an issue with one of the calibration constant for preshower and shower.
- Get lower/upper limit for PID.
- Get VDC efficiency, PID efficiency, trigger efficiency.
- He3 results do not change much.
- To Do:
- Fix the shower and preshower distribution: change calibration constant.
- Final carbon cross section as shown here.
- Subtract quasi elastic contribution for 2.2 GeV, DP =0% for
elastic He3 cross section was done by simulate a gaussian shape match
the residual of (data-sim). Detail can be found here
- Tried another method is used quasi elastic model from Chao, but
the model start very late (around 0.012 GeV), the experimental data for
first period start at ~0 GeV. So I can't applied this model to my
- Quasi elastic contribution found to be 8% correction to data cross section.
- Remain issue with He3 elastic cross section: semi-final elastic He3 cross section is here
- When subtract the nitrogen from He3, a scale factor of 2.0 need to apply to 1.1 and 1.5 GeV, but not for 2.2 GeV. Why?
- One possibility is the nitrogen density inside He3 is not
correct. So I did the pressure curves for elastic N2 at 2.2 GeV, at
this energy, we can see a very clean separation between elastic N2 and
elastic He3 peak. Code for pressure analysis can be found in the
- Density of N2 inside Proteus cell found to be: 0.104 amg
(which is very close to its value from database). The pressure curve is
- N2 elastic cross sections:
- Comparison between simulation and experimental data N2 cross section can be found here.
- There is an issue with setting DP=-2%. This setting has 20% disagreement between data and simulation.
- To do:
- Solve DP=-2% for N2.
- Finish tech note for pressure curve and n2 dilution for 2.2 GeV.
- Start inelastic analysis? the overlap with Vince's data.
- Preshower problem is fixed by averaging calibration constants of
nearby blocks. Block #7, and #15 have very low calibration constant
~0.03. After replace new calibration constants, there is no noisy
channel anymore. A noisy channel looks like this.
- Start to do inelastic analysis, steps are as followed
- Use same cut as the one used in 2.2 GeV elastic analysis.
- Run simulation with kinematic of the run, Ebeam, P0.
- Cuts applied: acceptance cut, analysis cut, target collimator cut.
- Get solid angle with correspond Dp cut.
- Cuts applied: acceptance cut, analysis cut, PID cut (shower,cherenkov,1 track).
- Count event survivied: N_total = N_plus + N_minus; use Q=Q_plus + Q_minus.
- Correct for efficiency, Charge, livetime, ps1.
- Target density; target length 34.3 cm; dEp=p0*momentum_bite; solid angle.
- Unpolarized cross section for 3He target at 2.2 GeV and 5.91 deg can be shown here.
- To Do:
- Careful analysis each data point.
- Include all other runs as well.
- Divide into many bins in dp.
- Unpolarized he3 cross section with different binning:
- 10 MeV bin, 4% momentum bite.
- 5 MeV bin, 5% momentum bite.
- 2 MeV bin, 4% momentum bite.
- Cross section plots are shown here.
- DP plot has 2 dips (strange). Reason:
- Preshower and shower cut, create 50% strength of these dips.
- Analysis cut also contribute.
- Acceptance cut too.
- To Do:
- Use P instead of R.gold.dp(reconstructed) variable.
- See how dp varies with focal plane quantities with and without acceptance cut.
Meeting minutes for second period
- Weekly meetings and Target lab status:
- Collaboration meetings: (Minutes and Talks)
April 10, 2006
June 21, 2006
October 18, 2006
Minutes(March 18-19, 2004) (.ps)
20-21, 2004) (May 20.ps)
Minutes(June 2-3, 2003) (.txt)
Minutes(October 3-4, 2003) (.ps)
Minutes(December 18-19, 2003) (.ps)
Last updated by Vincent Sulkosky 06/2007
Last updated for 1st period by Nguyen Ton 06/2018