Parallel Navigation J Apostolakis Overview Background Latest developments

Parallel Navigation J. Apostolakis

Overview • Background • Latest developments • Open Issues • Plans June 9, 2021 2 Parallel Navigation

Background • Parallel Navigation allows the tracking of tracks in multiple geometries simultaneously. Applies • ‘Straight’ tracks (neutral or not in field) • Curved tracks (charged in field) • Several classes involved at each step • G 4 Coupled. Transportation • G 4 Path. Finder (multiplexes for straight tracks) • G 4 Propagator. In. Field (charged only, +classes below it) • G 4 Multiple. Navigator (charged only) June 9, 2021 3 Parallel Navigation

Progress • Debugged problem • reported by A. Di Simone • Clear symptoms • Identified source of problem • Information not copied between G 4 Propagator. In. Field and (new class) G 4 VIntersection. Locator • Problem introduced in development introduced in Geant 4 9. 2 • Affects all uses & users • Correction included in geant 4 -09 -02 -ref-05 • Not yet included in patch of 9. 2 June 9, 2021 4 Parallel Navigation

Open issues – collect There are several types of problems, several in examples and tests • Cylindrical scoring • example. N 07 • Cavern background (scoring) • Code from Tatsumi • Geometrical (Importance) Biasing • Test 33 errors June 9, 2021 5 Parallel Navigation

Plans • Identify the source(s) of current problems • Typically it takes 2 -4 days of sustained effort to identify the source of a bug. • Timescale • As soon as possible June 9, 2021 6 Parallel Navigation

• Thanks! June 9, 2021 7 Parallel Navigation