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The NNSA DAQ-SystemThe present research requires us to cope with high count rates, to utilize a large number of high-density electronic modules, and to accomodate a number of experimental conditions and detector configurations. The NNSA group at TUNL is using Spectrodaq/SpecTCL data acquisition and analysis programs for use in readout of the TUNL segmented HPGe clover array and HPGe planar detectors. We are using the scripted readout package, which is easily configurable with CAEN 700 series digitizer. This package simplifies the software setup procedures for mid-to-high density detector configurations.
We extended the program's functionality by adding a new class of operations called CalibratedParameters that facilitates online analysis of HPGe detector gamma-ray spectra. Below we give an overview of the TUNL/NNSA Spectrodaq/SpecTCL acquisition system. There are essentially four parts of the acquisition and analysis system.
Data acquisition hardwareThe data acquisition hardware/trigger setup is comprised of the computer (Dual XEON LINUX machine), a PCI-to-VME interface module (SBS bit-3 620), an I/O module (CAEN 262), a specialized latching gate module to create the system BUSY, and the VME digitizers (ADC's, TDC's, etc.). The trigger system functions such that when an event
Software
Data Acquisition - Spectrodaq
Setup of the customized for {set i 0} {\$i $<$ 32} \{incr i} (lappend enables 1) set thresholds 15 for {set i 0\} {\$i $<$ 32} {incr i} { lappend thrlist $thresholds }
Next in the hardware.tcl file is the setup of individual
digitizer modules. Below is the description to setup an
ADC and TDC for a typical NNSA detector configuration.
On the first line, there is a description which specifies
the module type, i.e. CAEN V785, and the electronic ``base'' address
occupied by the module, i.e. 0xe6000000. Other setup commands
are somewhat intuitive for setting the pedestal thresholds
and enabled channels. An additional setup parameter Parameter names, which are descriptive of the signals plugged into the digitizer channel, are given in the module setup and are automatically propagated throughout the rest of the scripted software. In our typical setup we specify parameters for each quadrant of the clover detectors, [1Q# and 2Q#], for two planar HPGe detectors [3EHPGE 4EHPGE] and for the energy and PSD signal from a neutron detector [5MON_E 5MON_PSD]. ADC channels that are unused must still have a name associated with the input. Setup for the TDC is similarly straight forward, and details can be found in the CAEN module user's manuals.
module adc1 caenv785 slot 5 geo false base [expr 0xe6000000] adc1 config threshold $thrlist multievent false enable enables catch "adc1 config waitloops 10" adc1 config parameters {1Q1 1Q2 1Q3 1Q4 2Q1 2Q2 2Q3 2Q4 5MON_E 5MON_PSD blank01 blank02 blank03 blank04 3EHPGE 4EHPGE blank05 blank06 blank07 blank08 blank09 blank10 blank11 blank12 blank13 blank14 blank15 blank16 blank17 blank18 blank19 blank20 noindent for {set i 0} {$i $<$ 32} {incr i} {lappend tnables 1} module tdc caenv775 slot 9 geo false base [expr 0xe3000000] tdc config threshold $thrlist multievent false enable $tnables catch "tdc config waitloops 10" catch "tdc config commonstart true keepoverflow false range 630" tdc config parameters {1Q1T 1Q2T 1Q3T 1Q4T 2TQ1 2TQ2 2TQ3 2TQ4 1SHLDT 2SHLDT 3SHLDT 4SHLDT TPKOFF 3HPGET 4HPGET 5MONT t1p17 t1p18 t1p19 t1p20 t1p21 t1p22 t1p23 t1p24 t1p25 t1p26 t1p27 t1p28 t1p29 t1p30 t1p31 t1p32 Last is a command that determines the module readout order; in our case the TDC is readout first because it is the first to finish the analog-to-digital conversion process. set ModuleOrder {tdc adc1}
Scaler Setup
Scalar buffers are written to the event files on a fixable time
interval, and a separate scaler application window can be opened
while acquiring data. The scripted version of
Spectrodaq supports use of the 32 channel CAEN V830
module. In the present configuration of the NNSA electronics,
a series of coincidence logic modules permits the counting of scalars for
individual detectors, with a counting of raw triggers from
each detector as well as an accounting of the number
of scaler counters1 caenv830 base [expr 0xee000000] geo false header false trigger 1 counters config slot 11 packetize false autoreset false manualclear true counters config fpclearmeb false id 0x101 vmetrigger true wide true counters config header false counters config parameters {1_Q1 1_Q2 1_Q3 1_Q4 2_Q1 2_Q2 2_Q3 2_Q4 1SHIELD 2SHIELD 3SHIELD 4SHIELD 20HZ 3HPGE 4HPGE 5MON 0RAW 0MG 0MGLIVE BCI 1DRAW 1DMG 2DRAW 2DMG 1DMG.LIVE 2DMG.L 3DMG 4DMG 3DMG.L 4DMG.L 5MG 5MG.L } set ScalerOrder {counters1}
Data Analysis - SpecTCL
Lastly is the analysis software package SpecTCL. Using SpecTCL,
it is possible to generate 1- and 2-Dimensional histograms, and one can
generate
A specific example summarizes creation of parameters
and histograms for a neutron-monitor liquid-scintillator
detector. More complex manipulations are possible, but
the user is encouraged to consult the online user's manual for details.
The TUNL group has consulted with Ron Fox to create a new
class of pseudo parameter, called
X'=m . (X+ran(iseed)) +b
to eliminate spurious structures that would appear using other proceedures.
The NNSA group is using the TUNL HPGe segmented clover
detectors to evaluate the Spectrodaq/SpecTCL data
acquisition system. We have had two successful data
taking weeks, running with event rates of 3kHz
and deadtimes of around 15-20%. We consulted with Ron
Fox to increase the functionality of SpecTCL by creating
a new feature, CalibratedParameters, that permits the
display of energy calibrated spectra. We may pursue
further feasible developments that would incorporate
new 14-bit ADC's from CAEN and Mesytec, and
developments that would efficiently accommodate higher event rates.
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