MAP Multi Asic Pixel imager R Belllazzini Ronaldo
MAP Multi Asic Pixel imager R. Belllazzini Ronaldo. bellazzini@pi. infn. it
Scopo • Realizzare un ASIC a pixel adatto come piano anodico di tipo imaging-spettroscopico. (bumpbonding con cristalli, in rivelatori a gas proporzionali o a ionizzazione) • Implementare le connessioni di I/O e alimentazione dell’ASIC tramite la tecnologia Through Silicon Via per produrre un rivelatore 2 X 2 con limitati spazi morti. Partners INFN-Pisa, ASI, G&A Engineering
HED layout NHXM proposal 4 crystal+ASIC hybrids with limited dead space <0. 2 mm Cd. Te ASIC 20 mm Cd. Te microbonded to the ASIC ball bonding pads on the back side through via interconnections ASIC tiling 3
Conceptual scheme of focal plane detectors Readout Cd. Te Si detector Switcher Readout The system will need two separate termoregulators. The operating temperature of Cd. Te can be 40 -60°C higher than Si detector. 4
Pitch 200 m Pad passivation 180 m Metal pad 160 m Passivation opening for bump 38 m 200 180 160 38
Cd. Te-XPOL lateral view XPOL bonding pads (wedge) Bumps thickness 18 m Cd. Te XPOL Si chip 6
T=-40°C HED setup The readout electronics has an USB computer interface. On the readout board there is a FPGA that sends the commands to the ASIC, reads the flash ADC and performs the direct pedestal subtraction of the channels. Peltier PT 100 Water Cooling System Module NI temp (PT 100 e TC) USB Module NI relays 4 channels USB DAQ Acquisition and Control (C++) and Monitoring (Labview) Thermal Control and Temperature Performances • Current Cooling system: PC water cooling system (Coolit) together with a multistage cascade Peltier. • ON/OFF control of the Peltier using NI USB modules • An insulated hermetic box with N 2 flow prevents the condensation. • Tmin: 12/10/2010 - 40°C (better performance, Tmin< -50°C, can be reached using a phase change or a liquid chiller+Peltier) 7
Primi eventi 25 ke. V 14 ke. V 60 ke. V 12/10/2010 60 ke. V NHXM Pisa meeting R. Bellazzini 8
ottimi risultati da canali singoli i canali contigui senza segnale sono un ottimo guard-ring FWHM=730 e. V@60 ke. V 9
IXO Scopo • Upgrade del polarimetro X destinato al piano focale di IXO, con un ASIC XPOL-v 2 che sia capace del data rate previsto. X-rays Partners INFN-Pisa INAF Roma ASI
XPOL Performance He 20 -DME 80 1 bar size 15 x 15 mm 2, FOV=2. 6 x 2. 6 arcmin 2, polarization sensitivity 1% for 1 mcrab source in 100 Ks observation energy range 2 – 10 ke. V, energy resolution 20% at 6 ke. V, angular resolution 5”, timing resolution 5 s, efficiency see Figure 1, modulation factor see Figure 2, Polarization angle resolution~ 1 deg Dead time 10 s. (with XPOL-v 2) Figure 1: Efficiency. Figure 2: Modulation factor compared 11 with the Monte Carlo previsions.
On-line monitoring 6 ke. V event Large ROI → many channels without signal Real time pedestal subtraction 12 New ASIC under construction
Xpol ASIC upgrade The present ASIC has 200 s dead time mainly due to the digitalization of the signals. The mean event has ~50 pixels over threshold 10 pixels range ~1000 pixels ROI (1% of the channels) The experience shows that the ROI range is too conservative. 3 pixels range ~200 pixels ROI (factor 5 less channels) The pedestals are not stable need to readout the ROI again just after the event to read the pedestals. We have identified the problem. In the new version the pedestals will be stored in a memory and refreshed every 2 -4 hours (factor 2 dead time reduction) The new ASIC will sustain a clock increase from 10 MHz to 20 MHz (factor 2 dead time reduction) 13
New GEM New mechanics • Nuovo produttore Scienergy (Japan) più grandi, più stabili Ar 80 DME 20 9 cm
- Slides: 14