Readout System for the Edelweiss Dark Matter search introduction to the EDELWEISS DM search signal properties electronic DAQ setup DAQ software first results with the new system

physics and principles behind EDELWEISS Count rate: < 10-2 evt/kg/day! WIMP Scatt. WIMP Recoil nucleus  ER ~10 keV problems: low event rate background events by: β, γ and neutrons muon induced background simultaneous measurement of heat and ionization energy 𝑄= 𝐸 𝐼𝑜𝑛 𝐸 𝑟𝑒𝑐𝑜𝑖𝑙 𝐸 𝑟𝑒𝑐𝑜𝑖𝑙 = 𝐸 ℎ𝑒𝑎𝑡 − 𝑁𝑒𝑔𝑎𝑛𝑜𝑣−𝐿𝑢𝑘𝑒−𝐸𝑓𝑓𝑒𝑐𝑡 Ge-Detector at 18mK EDELWEISS -- readout system | joint AMS EDELWEISS meeting Bernhard Siebenborn

bolometer signals 2 heat signals: rise time ~1ms decay time ~100ms from NTD thermal sensor 4 ionization sig.: rise time <1µs decay time ~10ms from interleaved ring electrodes ADC-Counts 1 2 3 100 kHz heat channel 𝑥 𝑖 = 1 𝑛 𝑗 𝑎 𝑗 𝑃 𝑖 = 𝑥 𝑖 − 𝑥 𝑖+1 Time in ms NTD Time in ms ADC-Counts heat pulse EDELWEISS -- readout system | joint AMS EDELWEISS meeting Bernhard Siebenborn

EDELWEISS-II hardware setup special requirements: low noise low radioactivity detector at 18mK analog amplification at 100K with FET BBv2: analog/digital conversion at room temperature distribution-card: conversion to ethernet packages, distribution of commands and clock data acquisition, triggering and storage (DAQ) continuous control inner shielding cryostat shielding electric wire: ext. clock optical fibre: advantage: independent DAQ branches -> experiment continuous if one component fails voltage, bias: EDELWEISS -- readout system | joint AMS EDELWEISS meeting Bernhard Siebenborn

additional time-resolved ionization signal EDELWEISS 2 → EDELWEISS 3 𝝈<𝟒∙ 𝟏𝟎 −𝟖 pb → 𝝈<𝟐∙ 𝟏𝟎 −𝟗 pb 10 ID-400 detectors → 40 FID-800 detectors upgraded cryogenics new inner shield new cabling new readout integrated DAQ additional time-resolved ionization signal EDELWEISS -- readout system | joint AMS EDELWEISS meeting Bernhard Siebenborn

new integrated DAQ system 1x FLT = First Level Trigger card, historical name SLT = Second Level Trigger card = Master card 1x 80 - 120x detector at 18mK analog amplification at 100K with FET BBv2: analog/digital conversion, modify to 40MHz data acquisition, triggering and storage (DAQ) continuous control 40x data acquisition, triggering, clock also used in Auger and KATRIN inner shielding Cryostat outer shielding 1 integrated FPGA based DAQ electronics trigger closer to the detector -> faster trigger for the 40MHz signal EDELWEISS -- readout system | joint AMS EDELWEISS meeting Bernhard Siebenborn

Ionization channel electronics - with resistors or relays Ionization pulse gives a step function followed by an exponential decay Ionization pulse gives a step function – no decay after some time one has to reset with the relays to avoid ADC and capacitor saturation EDELWEISS -- readout system | joint AMS EDELWEISS meeting Bernhard Siebenborn

sampling of analogue data: in-house design bolometer box is the hardware control interface to the detector receives commands and clock from a distributor card DACs for applying bias to NTD and voltage to electrodes 6 channels with up to 200kS/s each, 16bit (100kS/s used) 2 channels with 40MS/s, 16bit and 2MS ring-buffer (50ms) (time-resolved ionization signal) EDELWEISS -- readout system | joint AMS EDELWEISS meeting Bernhard Siebenborn

time resolved ionization readout so far: 100kS/s  integrated ionization signal idea: time resolved ionization channels  position information of events (z-axis) implemented: faster sampling  40MS/s needed: internal fast trigger for event based readout (100kS/s ionization pulse triggers readout) Broniatowski, A. et al. Physics Letters B 681 (2009) B C D surface event with calibration source EDELWEISS -- readout system | joint AMS EDELWEISS meeting Bernhard Siebenborn

Data volume 40 bolometers x 6 channels x 16 bit x 100 kHz = 384 Mb/s (+ commands, headers,…) -> with 1 Gb/s ethernet one can stream all channels ~500 Mb/s for 40 MHz fast channel readout e.g. readout 4 FIC for 100 µs: 4∙16 𝑏𝑖𝑡 ∙40 𝑀𝐻𝑧 ∙ 100 µ𝑠=256 𝑘𝑏𝑖𝑡 or 0.5 ms transfer time NTD EDELWEISS -- readout system | joint AMS EDELWEISS meeting Bernhard Siebenborn

electronic components installed in Modane 300K 100K 1K 100mK 10mK 300K 100K 1K EDELWEISS -- readout system | joint AMS EDELWEISS meeting Bernhard Siebenborn

Modane Crate – 20x FLT Mini Crate – 4x FLT EDELWEISS -- readout system | joint AMS EDELWEISS meeting Bernhard Siebenborn

? Connection scheme Master Card BB1 FLT card (20x) Backplane BB2 FPGA ALTERA cyclone II ring buffer QDR RAM commands clock PCIe interface Master Card BB1 Backplane 16x FIFO BB2 BB1 fiber in/out up to 6 BBs BB1 PCIe BB23 powerful Computer open SUSE 12.2 graphical user interface 2 programs readout loop (SAMBA backend) ORCA backend ? EDELWEISS -- readout system | joint AMS EDELWEISS meeting Bernhard Siebenborn

Integration of external detectors Muon-Veto System 1 FLT card is configured to readout the Muon-Veto card Muon-Veto card is connected with a pair of fiber, like a BBv2 FLT sends 48 bit timestamp to Muon Veto Muon Veto attaches 6 bit Veto status and sends 54 bit back FLT checks timestamp if it is still correct EDELWEISS -- readout system | joint AMS EDELWEISS meeting Bernhard Siebenborn

Muon-Veto readout and processing FLT in Veto –mode check timestamp 48 bit timestamp (10µs) Veto-Card in VME Crate 6 bit Veto status Crate PC SAMBA PC used as trigger/veto signal 000000000, Status 5…0, ERROR 16 bit msb timestamp 16 bit medium sb timestamp 16 bit lsb timestamp 0000000000000000 000000000000000000000000 EDELWEISS -- readout system | joint AMS EDELWEISS meeting Bernhard Siebenborn

ORCA based control interface ORCA is a DAQ software for low-level hardware control/readout and high-level experimental configuration and run control read / write access to all Crate registers useful for setup or initialize the Crate e.g. in a test mode, or to crosscheck settings configured by SAMBA ORCA interface is under development, new functions are implemented at the time. [Till Bergmann] Other experiments using ORCA: e.g. SNO, Majorana, KATRIN, EXO http://orca.physics.unc.edu EDELWEISS -- readout system | joint AMS EDELWEISS meeting Bernhard Siebenborn

SAMBA DAQ System – in-house developed EDELWEISS -- readout system | joint AMS EDELWEISS meeting Bernhard Siebenborn

trigger algorithm T0: heat channel(s) < T1: ionization channel(s) 3. filter 1. heat signal 100kHz 2. heat signal 500Hz 4. heat trigger _ _ _ Xi = |Xi+ - Xi-| _ Xi+ Xi- Xi+1 …. < S of N thresh. T1: ionization channel(s) 3. subtract plots 1. ionization signal 100kHz 4. filter 5. ion. trigger Ai __ < < A S of N 2. teach-in a periode thresh. Metadata: trigger rate, noise power, event maximum, event timestamp EDELWEISS -- readout system | joint AMS EDELWEISS meeting Bernhard Siebenborn

different trigger levels & additional detectors e.g.: trigger on all channels (2x heat and 4-6 ionization) trigger on all heat channels only trigger on 1x heat and 1x ionization channel geometrical selection of readout channels Taking external detectors into account: muon veto system EDELWEISS -- readout system | joint AMS EDELWEISS meeting Bernhard Siebenborn

Projection EDELWEISS-3 40 Bolometer x 6 Channels 16bit ADC, 100kHz up to 40 MHz time resolved ionization channel integrated DAQ optimized shielding test for EURECA DAMA/LIBRA (3s) CRESST (2s) CoGeNT ROI (90%CL) CDMS+EDELWEISS (90%CL) ZEPLIN III (90%CL) CDMS Low Mass (90%CL) Xenon10 Low Mass (90%CL) EDELWEISS-III 3000 kgd(90%CL) Xenon100 (90%CL) EDELWEISS-III (3000 kg.d background free) Legende fehlt Trotta et. al. (95%CL) Buchmueller et. al. (95%CL) EDELWEISS -- readout system | joint AMS EDELWEISS meeting Bernhard Siebenborn