Date post: | 18-Dec-2015 |
Category: |
Documents |
Upload: | samuel-hardy |
View: | 213 times |
Download: | 0 times |
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
EDELWEISS -- readout system | joint AMS EDELWEISS meetingBernhard Siebenborn
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:
EDELWEISS -- readout system | joint AMS EDELWEISS meetingBernhard Siebenborn
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
EDELWEISS -- readout system | joint AMS EDELWEISS meetingBernhard Siebenborn
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
EDELWEISS -- readout system | joint AMS EDELWEISS meetingBernhard Siebenborn
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
EDELWEISS -- readout system | joint AMS EDELWEISS meetingBernhard Siebenborn
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)
EDELWEISS -- readout system | joint AMS EDELWEISS meetingBernhard Siebenborn
9
time resolved ionization readout
EDELWEISS -- readout system | joint AMS EDELWEISS meetingBernhard Siebenborn
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
EDELWEISS -- readout system | joint AMS EDELWEISS meetingBernhard Siebenborn
11
electronic components installed in Modane
EDELWEISS -- readout system | joint AMS EDELWEISS meetingBernhard Siebenborn
300K
100K
1K
300K
100K
1K100mK
10mK
12
Modane Crate – 20x FLTMini Crate – 4x FLT
EDELWEISS -- readout system | joint AMS EDELWEISS meetingBernhard Siebenborn
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
?
EDELWEISS -- readout system | joint AMS EDELWEISS meetingBernhard Siebenborn
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
EDELWEISS -- readout system | joint AMS EDELWEISS meetingBernhard Siebenborn
15
Muon-Veto readout and processing
EDELWEISS -- readout system | joint AMS EDELWEISS meetingBernhard Siebenborn
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
EDELWEISS -- readout system | joint AMS EDELWEISS meetingBernhard Siebenborn
17
SAMBA DAQ System – in-house developed
EDELWEISS -- readout system | joint AMS EDELWEISS meetingBernhard Siebenborn
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.
EDELWEISS -- readout system | joint AMS EDELWEISS meetingBernhard Siebenborn
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
EDELWEISS -- readout system | joint AMS EDELWEISS meetingBernhard Siebenborn
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
EDELWEISS -- readout system | joint AMS EDELWEISS meetingBernhard Siebenborn