1. µTPC Reconstruction Status Report (…mostly a late night / weekend project … ) D. A. Jensen March 1, 2007

2. Overall Plan Goal – reconstruct tracks from the µTPC ( study tracks, efficiency, resolution… ) Data Sources –The Data –Monte Carlo –Sub (Monte-Carlo) for testiing

3. Goals – contd. Provide a basis for detailed thinking and discussion Think very concretely about problems like data formats, signal shapes, noise sources and levels, geometry …

4. The µTPC

5. Monte Carlo A simple muon track generator Include dE/dx to make drift electrons Multiple scattering Track energy loss Future: g4beamline for more features

6. Some MC details dE/dx Multiple scattering ‘reasonable’ number of electrons for a signal ( pick a momentum – how much range will be set up? )

7. Geometry A geometry file with µTPC details Wire positions Trigger counter positions

8. Reconstruction Read Data ( Dan, M-C ) –Mt. plot Find ‘bumps’ Find Tracks Correlate Views to form Tracks Studies Along the Way

9. Hits on the wires – mountain plot

10. Find the Bumps Based on ‘fbump’ used in MI-RW mon. –Well tested and tuned Finds signals above background Does ‘histogram calc’ of mean, sigma Will do minuit fits to detailed shape only gaussian so far

11. Training Sample for fbump.for

12. Fitting ‘bumps’ from fbump.for

13. Detailed thinking about LAr Signals To the left is a fit to Dan Edmonds ‘B’ plane electronically simulated signal. These samples also provide a noise sample So far assuming the collection plane signal is ~ gaussian

14. Track Finding Several Possible Methods –a) Hough search ( Yale, neutrino exps.) –b) Find a hit, chase the track –c) Line Search  current effort Find ‘Lines’ ( one view objects ) first This is an effort to find and study simple tracks

15. Clean ‘lines’ to tune the program

16. Look at results ( 2/n examples )

17. Add noise, ineff. Being debugged

18. The ‘ To-Do’ list Monte-Carlo –Cleaning up dE/dx, e’s / dE –Better simulation of pulse shapes –Add noise ( electronic, Ar decay, … ) Read / Mt. plots –More read format options –Better display of ‘found’ bumps Track Finding –Validate line finding with noise and eff. effects –Geometry integration Views correlation ( anglular to 3D xy ) > Tracks

19. ‘To – Do’ Continued It may be interesting to generate ‘more realistic’ µ tracks – use ‘g4beamline’. Pulse shapes – fits to induced pulse samples for example. Some work done based on Dan’s electronic simulation signals. Other track finding methods –Have written some code to do the track follow –Started ‘thinking’ about the Hough transformation

20. Argon Decay 39 A decays Note by K. MacDonald says ~1.5 ‘events’ per liter per second. This is clearly not an issue in the µTPC