Pixie-4 Express User Manual Version 4.31
© 2017 XIA LLC 3
3.6.1 File Series to break up long data acquisition runs...............................................................29
3.6.2 File Series to scan filter parameters....................................................................................30
3.6.3 File Series Analysis.............................................................................................................31
4Data Acquisition and Data Structures.................................................................................................32
4.1 Run Types...................................................................................................................................32
4.1.1 MCA Runs ..........................................................................................................................32
4.1.2 List Mode Runs...................................................................................................................32
4.1.3 Summary of Run Types ......................................................................................................34
4.2 Output Data Structures................................................................................................................35
4.2.1 MCA Histogram Data Structure .........................................................................................35
4.2.2 List Mode Data Structures ..................................................................................................35
4.2.3 List Mode Data Values .......................................................................................................42
5Hardware Description.........................................................................................................................44
5.1 Analog Signal Conditioning........................................................................................................44
5.2 Pulse Processing..........................................................................................................................45
5.3 Digital Signal Processor (DSP) and Event Building...................................................................45
5.4 PCI Express Interface..................................................................................................................46
6Theory of Operation............................................................................................................................47
6.1 Digital Filters for -ray Detectors ...............................................................................................47
6.2 Trapezoidal Filtering in a Pixie Module .....................................................................................49
6.3 Baselines and Preamplifier Decay Times ...................................................................................50
6.4 Thresholds and Pile-up Inspection..............................................................................................51
6.5 Filter Range.................................................................................................................................53
6.6 Data Capture Process..................................................................................................................54
6.7 Dead Time and Run Statistics.....................................................................................................54
6.7.1 Definitions...........................................................................................................................54
6.7.2 Count time and dead time counters.....................................................................................59
6.7.3 Count Rates.........................................................................................................................61
6.7.4 Dead time correction in the Pixie-4 Express.......................................................................62
7Synchronized Data Acquisition..........................................................................................................63
7.1 Clock Distribution.......................................................................................................................63
7.2 Trigger Distribution ....................................................................................................................63
7.2.1 Trigger Distribution Within a Module................................................................................63
7.2.2 Trigger Distribution Between Modules ..............................................................................64
7.2.3 Trigger Distribution between PXI chassis ..........................................................................64
7.2.4 External Triggers.................................................................................................................64
7.3 Run Synchronization...................................................................................................................65
7.4 External Gate and Veto...............................................................................................................66
7.4.1 External Gating Scenarios...................................................................................................66
7.4.2 Shaping of External Signals................................................................................................67
7.4.3 Marking Events...................................................................................................................68
7.4.4 Rejecting Events .................................................................................................................68
7.4.5 Counting Veto/Gate Pulses and Times................................................................................69
7.4.6 Timing Diagrams for Application Examples......................................................................69
7.5 External Status............................................................................................................................70
7.6 Coincident Events.......................................................................................................................70
7.6.1 Coincidences Within a Module...........................................................................................70
