LNS Catania, February 20-23, 2012 Status of the mini-DOM in ANTARES V. Popa
Short reminder The idea of the project (“mini-DOM”): A multi-PMT (5 PMTs) in an ANTARES sphere, enabled to receive power / commands and send data from / to the standard ANTARES LCM electronics, will allow to disentangle the L1 coincidence rate as a function of the space angle between the PMTs. A first multi-PMT test in deep sea (prior to a full KM3NeT DOM). Main difficulty: The signal from the PMTs is in standard form, and the ANTARES ARSs require analog input.
The electronic board has to: - combine the LVDS signals from two or more PMTs and deliver an “analog” signal to the ANTARES ARS - ensure the “slow control” of the device: commands from shore on each run configuration, send information on the acquisition status, control the PMT high voltage - ensure the power to all the components inside the DOM
The miniDOM becomes real at CPPM! (Almost) all components are there and undergo tests Pressure tests completed in Catania; the upper hemisphere send (arrived?) to CPPM
New vacuum valve (mounted in Catania) “old” vacuum valve
Last week, at CPPM. The lower hemisphere, with 5 PMTs, from NIKHEF
+ Electronics from ISS The lower hemisphere, with 5 PMTs, from NIKHEF + => All ingredients! Tests started… Standard LCM (CPPM)
Test summary: • Powering the electronics from the switchable LCM 48V lines. Failed due to the large capacitors at the board power entry; to be solved soon (various possibilities investigated) • Communication with the board trough the LCM (RS232 and MODBUS) OK on all channels; configuration of the board and of the high voltages and thresholds works properly. A friendly user interface to be developed soon. • PMT’s coupled to the electronic board.
Tests in the black box. One connector (base of PMT 2) disintegrated due to bad soldering . 4 remaining channels OK. The connector could be changed with a new one, to recover also the fifth PMT.
First 30 s run, minimum HV and thresholds, L0 background rate about 75 kHz
After some firmware corrections, first runs in waveform mode OK. • All news are now available on e-log. https://sbgelog.in2p3.fr/INTEGRATION_CPPM/
To do list: • solve the power problem • recover the fifth PMT • integrate the mini-DOM • final tests • Conclusion: We are optimistic! The mini-DOM could be ready for integration in the IL011 by the end of the month!