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

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

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 …

The µTPC

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

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

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

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

Hits on the wires – mountain plot

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

Training Sample for fbump.for

Fitting ‘bumps’ from fbump.for

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

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

Clean ‘lines’ to tune the program

Look at results ( 2/n examples )

Add noise, ineff. Being debugged

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

‘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

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