An Analysis Task List

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June 06, 2012 Updates to the Analysis Task List

  1. Backgrounds
    1. For search of source of the activation of Cs & I, we need to consider fast neutron production in our 6Li-loaded shield. Kyle will estimate the rate of neutron capture in shielding and from there we need to estimate using known fast neutron production rate how many of them will end to be captured in Cs and Iodine and how much they contribute neutron/gamma background that we see.
      • MCNPX uses an internal model to make alphas and tritons in 6Li(n,alpha)t reactions; there is not a library for this or at least there isn't a standard one. Incident alpha and triton libraries exist in the format that MCNPX reads, but MCNPX itself is not capable of reading alpha or triton libraries. After producing alphas and tritons, MCNPX will track them but they do not do anything other than rattle around and lose energy until they are rouletted. I will do some more checking to make sure this is the case and if it is, I will look into modeling captures in the lithium and then model or estimate fast neutrons according to the captures. -- Kyle
      • Update: See results from modeling flux across surfaces and modeling a fast neutron source at June e-log entry. The total signal due to fast neutrons is approximately 0.04% of the signal due to (n,γ) on hydrogen only.
    2. There seems to be different fast decay components under pulses, these we can see in the lost pulses. We need to compare these signals from LH2, Cl, Al.

June 01, 2012 An Analysis Task List

This modified list of analysis tasks which is based on the list that was discussed in EC and among others and circulated by Mike.

  1. Radiation Levels - Calculate expected rad levels outside of cave shielding for Al, CsI, and CCl4 targets, needed urgently to prepare targets for runs. (Kyle)
    • Status: Done. We have dose levels for Al, Cl, and CsI. Ran low statistics calculations at 1MW for Cl and Al with 3.5in collimator and 2MW for CsI with 3.5in collimator, high statistics at 2MW for Cl and Al with 3.5in collimator. See results at Analysis_Summaries#MCNPX_Photon_Dose_Calculations.
  2. Ortho/Para Analysis - Aim is to put an upper bound on ortho concentration so that we can judge whether or not a LH2 target-empty run is required before the shutdown:
    1. We need to look at existing M4 data and find out; sensitivity, stability. See how many neutrons we see incident M4. Make ratios M4 and M1 and see behavior during longer time periods. (Chad)
      • Status:
    2. Analyze neutron energy dependence of transmission using M4.
      • Status:
    3. Look at integrated gamma detector signal ratio between rings if they change in time.
      • Status: Code exists to use the detector array for O/P ratio calculations. The detectors give more or less gibberish for answers.
    4. Make ratio between integrated detector signal and M4 and see if this ratio is changing with time.
      • Status:
    5. Compare M4 signal to Kyle’s MCNP results (Kyle, Chad)
      • Status: Analysis code already exists but it will be difficult to merge our existing empty target run and any current runs because the empty run is 16ms of data per accelerator pulse and all hydrogen data after filling is 12.8ms per pulse. Unfortunately, we lost all of the early target filling time due to the daq not working and no data exists of the filling time for analysis. A new empty run makes the analysis of the data we have taken easy. See results from using the 16ms empty run and 12.8ms data at Analysis_Summaries#Results_from_opratio_code.
      • Update (June 17): See newest results at Analysis_Summaries#Results_from_opratio_code_as_of_Sunday_6.17.12. The para concentration from comparing the actual transmission to the MCNPX transmission is now ~1 sigma from 1.00 rather than nearly 5 sigma from 1.00.
  3. Backgrounds – goal is to deduce backgrounds caused by beta-delayed and prompt gammas(Serpil)
    1. analyze beta-decay gammas, quality of data, what nuclei we think that we see, do we need more decay data
      • Status: in progress
    2. compare shutter-closing beta delayed gammas with information from lost pulses for H2, Al, CCl4, we need to understand what is back ground under our pulses (Serpil)
      • Status: in progress
    3. use deduced prompt and beta-delayed gammas and compare with MCNP results. (Serpil, Kyle)
      • Status: in progress
    4. look at ring dependence of prompt and beta-delayed background signal. Compare again with MCNP (Serpil, Kyle).
    5. sort out existing unknown source of background beyond Al, CsI (Serpil, Kyle)
      • Status: in progress
  4. Geometrical Factors - calculate geometrical factors for the CsI target for eventual analysis of CsI asymmetry data (Kyle) – maybe we do not need this
    • Status: Done. Though, we may not use CsI. Calculations for new targets only take a few hours to finish. Geometrical factors will be posted on the e-log and linked on Analysis_Summaries#Geometrical_Factors for easy recovery.
  5. Beam Fluctuations - contribution of beam fluctuation to statistical error. This will have effect to running time, shot noise, flux (Elise, Nadia)
    1. Status: in progress
  6. Data Analysis Cuts - establish list of "standard" cuts for data analysis (Nadia et al.)
    • Status: in progress
  7. Electronic/False Asymmetries
    1. what is the upper limit to asymmetry with the running configuration – M1 connected, 3 rings detected
    2. If we have electrical asymmetry, does it have ring dependence?
      • Status: Done. No. We do not have an electronic asymmetry.
    3. establish upper bound for asymmetry that we can have in background signals from Al, Cs, I prompt and beta decay
      • Status:
  8. Polarization - establish the beam polarization with errors
    • Status: See Polarimetry for several incremental updates.
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