• 2016
• 2017
  
• 02/21/2018
• 03/14/2018
• 03/21/2018
• 05/23/2018
• 06/20/2018
• 07/18/2018
  

• 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 situation.
• 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 following link:
  
• https://github.com/nguyenton68/Analysis/tree/master/n2_dilution_pressure_curve
• 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 shown here.
• 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.
  
• Simulation:
• 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.
• Data:
• 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[0] instead of R.gold.dp(reconstructed) variable.
• See how dp varies with focal plane quantities with and without acceptance cut.
  

1. Weekly meetings and Target lab status:

• Collaboration meetings: (Minutes and Talks)
  

• 2007

• 2006

• 2005

• 2004

• 2003

• 2002

•  2001

Last updated by Vincent Sulkosky 06/2007

Last updated for 1st period by Nguyen Ton 06/2018