Bernhard Siebenborn introduction to the EDELWEISS DM search signal properties electronic DAQ setup DAQ software first results with the new system Readout

Bernhard Siebenborn

introduction to the EDELWEISS DM search

signal properties

electronic DAQ setup

DAQ software

first results with the new system

Readout System for the Edelweiss Dark

Matter search

2

physics and principles behind EDELWEISS

Count rate:

< 10-2 evt/kg/day!

WIMP Scatt. WIMP

Recoil nucleus ER ~10 keV

problems:low event ratebackground events by:β, γ and neutronsmuon induced background

Ge-Detector at 18mK

simultaneous measurement of heat and ionization energy

EDELWEISS -- readout system | joint AMS EDELWEISS meetingBernhard Siebenborn

3

bolometer signals


2 heat signals: rise time ~1msdecay time ~100ms

from NTD thermal sensor

4 ionization sig.: rise time <1µsdecay time ~10ms

from interleaved ring electrodes

NTD

NTDTime in ms

AD

C-C

ount

s

heat pulse

AD

C-C

ou

nts

1 2 3

100 kHz heat channel

𝑥𝑖=1𝑛∑𝑗 𝑎 𝑗

𝑃 𝑖=𝑥𝑖−𝑥 𝑖+1

Time in ms

4

EDELWEISS-II hardware setup

detectorat 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

ext. clockelectric wire:

optical fibre:


cryostat shielding

special requirements:low noiselow radioactivity

advantage: independent DAQ branches-> experiment continuous if one component fails

inner shielding

voltage, bias:

5

EDELWEISS 2 → EDELWEISS 3

pb → pb10 ID-400 detectors → 40 FID-800 detectors

upgraded cryogenicsnew inner shieldnew cablingnew readout

integrated DAQadditional time-resolved

ionization signal


6

new integrated DAQ system

detectorat 18mK

analog amplification at 100K with FET

BBv2:analog/digital conversion, modify to 40MHz

data acquisition, triggering and storage (DAQ)

continuous control


Cryostat outer shielding

40x

80 - 120x

1x

1 integrated FPGA based DAQ electronics

trigger closer to the detector -> faster trigger for the 40MHz signal

data acquisition, triggering, clock

also used in Auger and KATRIN

1x

inner shielding

FLT = First Level Trigger card, historical nameSLT = Second Level Trigger card

= Master card

7

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 decayafter some time one has to reset with the relays to avoid ADC and capacitor saturation

8

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)


9

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)

B

C

D

surface event with calibration source

Broniatowski, A.et al.Physics Letters B 681 (2009)

10

Data volume

NTD

NTD

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 readoute.g. readout 4 FIC for 100 µs:

or 0.5 ms transfer time


11

electronic components installed in Modane


300K

100K

1K

300K

100K

1K100mK

10mK

12

Modane Crate – 20x FLTMini Crate – 4x FLT


13

Connection scheme

FLT card (20x)

FPGAALTERAcyclone II

ring bufferQDR RAM

BB1

BB2

BB1

BB1

BB23

fiber in/outup to 6 BBs

commands clockPCIe interface

Backplane

PC

Ie16

x F

IFO

Master Card

powerful Computer open SUSE 12.2 graphical user interface2 programs readout loop (SAMBA backend) ORCA backend

?


14

Integration of external detectorsMuon-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


15

Muon-Veto readout and processing


FLT in Veto –mode

check timestamp

48 bit timestamp (10µs)

Veto-Card in VME Crate48 bit timestamp (10µs) 6 bit Veto status

Crate PCSAMBA 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 0000000000000000

000000000000000000000000

16

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


17

SAMBA DAQ System – in-house developed


18

trigger algorithm

T0: heat channel(s)

_ _ _Xi = |Xi+ - Xi-|

_Xi+

_Xi- _

Xi+1 ….

T1: ionization channel(s)

2. heat signal 500Hz1. heat signal 100kHz 3. filter

<

thresh.

S of N

4. heat trigger

1. ionization signal 100kHz

2. teach-in a periode

<

3. subtract plots 4. filter

S of N

5. ion. trigger

<A__

Ai

thresh.


Metadata: trigger rate, noise power, event maximum, event timestamp

19

different trigger levels & additional detectors

e.g.:

1. trigger on all channels (2x heat and 4-6 ionization)

2. trigger on all heat channels only

3. trigger on 1x heat and 1x ionization channel

4. geometrical selection of readout channels


Taking external detectors into account:muon veto system

20

Projection EDELWEISS-3

DAMA/LIBRA (3 )s

CRESST (2 )s

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)

Trotta et. al. (95%CL)Buchmueller et. al. (95%CL)

40 Bolometer x 6 Channels

16bit ADC, 100kHz

up to 40 MHz time resolved ionization channel

integrated DAQ

optimized shielding

test for EURECA


Documents

Bernhard Siebenborn introduction to the EDELWEISS DM search signal properties electronic DAQ setup DAQ software first results with the new system Readout