The AMANDA TWR (Transient Waveform Recorders) DAQ
THE 2 RACKS WITH 4 VME CRATES CONTAINING 61 TWR MODULES
During the South Pole Austral season 2002/2003 a new AMANDA DAQ system,
the TWR (Transient Waveform Recorders) DAQ
has been set up
(Andrea Silvestri and Wolfgang Wagner ).
The major difference of the TWR DAQ system compared with the standard
AMANDA DAQ system is the recording of the whole PMT pulse waveform. We are working in order to
connect all channels of the current AMANDA II detectors, i.e. the working subsample of 680 channels. In
total we estimate to connect a total of 580 operating channels. The channel outputs used for the waveform
information are divided in two classes: 1. Optical channels, the prompt output from the ORB III of string
19 to 14 and from ORB II of string 13 to 11; 2. Electrical channels, the prompt output from the SWAMP of string
10 to 1. We are using also the additional SWAMP output for channels where the optical output information
might be distorted or even completely lost (SWAMP output of string 19 to 11).
The waveforms are recorder on a 1024 nsec window with a time binning of 10 nsec, which is the 100 MHz clock of the
VME TWR module.
The current TWR DAQ is located in 2 racks where previously was the AMANDA A DAQ. Each rack contains 3 VME crates
with the following number convention:
RACK 1
- crate TWR 1 : is the current old TWR DAQ: currently no TWR modules;
- crate TWR 2 : TWR crate with 16 SIS 3300 modules, one VME SIS 3100 bridge master, one GPS Latch;
- crate TWR 3 : TWR crate with 16 SIS 3300 modules, one VME SIS 3100 bridge master;
RACK 2
- crate TWR 4 : TWR crate with 16 SIS 3300 modules, one VME SIS 3100 bridge master;
- crate TWR 5 : TWR crate currently with 12 SIS 3300 modules, one VME SIS 3100 bridge master;
- crate TWR 6 : TWR master crate containing 5 VME SIS 3100 bridges, a muster module MBS trigger board
and a RIO3 module;
Each SIS 3300 TWR module can contain 8 channels.
Currently the TWR DAQ is running with the standard AMANDA trigger at Majority Logic = 24, i.e with a
trigger rate of approximately 95 - 100 Hz.
With a total of three crates, i.e. 384 TWR channels we get a data volume of around 24 GB/day.
The threshold for the feature extraction has been set up at 20 mV for optical channels and 100 mV for electrical
channels respectively. The threshold for electrical channels must be larger in order to get rid of a large
number of waveforms produced just by noise background.