Titles: TFTM ============= Contact: N. Tagg, Guelph Titles Files ------------ fitter.dat Verification ------------ TFTM 1 ------ Description ----------- This bank contains input data for the time fitter. Data Words - TFTM 1 ------------------- Fixed length Database Header. See titles_dbhdr.html Data types: B(bit), I, F, D(double), H(hollerith 4 char) Type Variable [symbolic command] Description in ftm_com/ ---- -------- ------------------------------- 1 I MinTubesAfterCut [muon_fit_which_charge] Minimum number of tubes to attempt a fit. Fitter will keep at least this many tubes to fit with. 2 I WhichCharge [muon_fit_which_charge] Charge to use when analyzing tubes. 1=Qhs, 2=Qhl, 3=Qlx, 4=Max(Qhl,Qlx), 5=Qm (KPMT_QM) 3 I NumThrowAwayLast [muon_fit_throw_away] Number of latest tubes to throw away. 4 I ExitGridPoints [muon_fit_exit_guess_points] Points to grid-search near the estimated exit point. Jitters the exit point on a hex grid. More points increases computation time. 5 I DirGridPoints [muon_fit_dir_guess_points] Points to grid-search in track direction. More points means more computation. If more than 812 points are selected, points are sampled randomly rather than on a grid. (N*2+1)^2 6 I NumChopAtOnce [muon_fit_cut_at_once] Number of tubes to chop at a time when improving fit 7 I NumChopMax [muon_fit_max_cut] Maximum number of tubes to chop when improving fit 8 Reserved for future use 9 Reserved for future use 10 F ChargeMin [muon_fit_min_charge] Minimum integrated charge. Do not attempt to fit any event with total charge less than CHARGEMIN. 11 F ChargeCutRatio [muon_fit_charge_cut_ratio] For computing min charge to keep a tube. See Note 1. 12 F EtaGuessMin [muon_fit_min_eta] Minimum zenith angle to search for on grid, radians. See Note 2. 1.57 = Search only for downward going muons ( pi/2 < eta < pi ) 0. = Search on all directions ( 0 < eta < pi ) 13 F ExitGridAngle [muon_fit_exit_grid_angle] Width of grid spacing, degrees. Fitter searches the theta,phi coordinates of the exit point on a hex grid with a spacing of this angle. 14 F TimeWindow [muon_fit_time_window] Time window of trial searches, ns. Trial fit computes chisq/tubes for tubes where |tfit-t| <window 15 F ChiSqGoal [muon_fit_chisq_goal] Chi-squared per tube fitting goal 16 F FitToRadius [muon_fit_enter_radius] Initial radius to fit to. (cm) See Note 2. 17 F WaterLevel [muon_fit_water_level] Waterlevel z-coordinate (cm) for partial-fill fits. 18 F RMSMax Upper limit on RMS time. 19 Reserved Cheat word! 20 I DebugMsgs [muon_fit_info/_debug] Flag to dump debugging messages to iqlog and iqprnt. 1 = informative, fit-by-fit results printed 2 = Progress messages, debugging only 21 I FileDump [muon_fit_dump_files] Flag to dump text files (0=don't write, 1=write) Intended for debugging/development work. See code. 'ftm_chispace.dat' -> A map of every chisq value calculated for values t_exit, theta, phi, eta, psi 'ftm_tubes.dat' -> A list of tubes in event with values calculated by fit. 22 I WhichTime [muon_fit_multiphoton_time] Use of Multiphoton PCA times != 1 Use regular PCA times (KPMT_PT) = 1 Use Multiphoton PCA times (KPMT_PTM) 23 I WhichSig [muon_fit_mpca_time_sigma] Use of Multiphoton PCA PMT transit time RMS != 1 Use TJITT (1.6ns) as Tube time sigma = 1 Use MPCA PMT transit time RMS (KPMT_PTMS) 24 I ANxxPCAMask ANxx PCA Mask. 25 I ANxxNuMask ANxx NU Mask. Notes ----- 1) (Integrated Charge of Event) x (Charge Cut Ratio) = Q_cut. All tubes with Q < Q_cut are ignored by fitter. 2) Fit position (ftxv bank) is at this radius. Since FTM fits only to a track, not a point, the start position of the particle is undefined. FTM chooses a point at this radius to be the fit vertex reported in the reconstruction. This is useful particularly if the MC generates events in a shell with this radius. 3) The fitter will ignore tubes with Z-coordinate greater than the given water level. Tubes above the water will not recieve Cherenkov light on a wide cone, so these tubes are only confusing to the fitter. Note that partial fill fits are much more susceptable to fitter inaccuracies, even with this fix. Set this value to be > 900 cm to ignore this feature. TFTM 2 ------ Description ----------- This bank contains data used by the fitter, rather than control words. This data is used to search track directions in a consistent fashion. Data Words ---------- Word 1 - Number of coordindinate pairs to follow Words 2-1625- Theta-phi coordinates, in radians. These are theta-phi coordinates of points 'evenly' spaced on a unit sphere. Thanks to Bernie Nickel at U of Guelph for provding this. The points were found by first taking an isocohedron vertex coordinates, then subdiving each face and projecting the subdivided grids back onto a sphere. The result is a set of 812 points, making a progressively finer grid. The mean angle between neihboring points is 8.36 degrees.