Transcript The CASCADE Neutron Detector: R&D in DETNI

n-XYTER
Front-End Boards
Christian J. Schmidt,
GSI Darmstadt
CBM STS Workshop, Karelia, June 1 – 4, 2009
Data Driven Front-End: Asynchronous Channel Trigger
detection of statistical, poisson distributed signals
comparator
charge
input
FAST
shaper 18.5 ns
peaking
charge
preamp
SLOW shaper
(2 stages)
140 ns peaking time
Time Walk
Compensation
circuit
trigger
timestamp reg.
PDH
reset
Peak
detector &
hold,
free running
dig. FIFO
pulse height
output
analogue FIFO
Asynchronous registry and storage in
4-level fifo guarantees data loss < 4 %
when read-out through token ring
Read-out through balancing token ring
 32 MHz data registry and read-out
The DETNI ASIC 1.0, a front-end evaluation chip in AMS 0.35µ
CBM STS Workshop, Karelia, June 1 – 4, 2009
n-XYTER Front-End Topology
CBM STS Workshop, Karelia, June 1 – 4, 2009
"Simple" FEB for the n-XYTER Starter Kit

A simple hybrid PCB with signal fan-in,
ADC and interconnect to SysCore DAQ
chain

Allow development of the DAQ chain

Allow the readout of various detector
prototypes, using the n-XYTER frontend chip
CBM STS Workshop, Karelia, June 1 – 4, 2009
n-XYTER FEB: At the limits of PCB-technology
Interference point of many technologies,
each imposing limiting boundary conditions:

A simple hybrid PCB with
signal fan-in, ADC and
interconnect to SysCore
DAQ chain

Chip-In-Board solution
avoids space eating vias

allows pitch adaptation:

50,7 µm on chip to

PCB side 101,4 µm
on two levels
CBM STS Workshop, Karelia, June 1 – 4, 2009
n-XYTER FEB Rev. C
In spite of bonding difficulties, managed
to realize

10 Rev. C boards, fully functional

4 rev. B boards with 64 channels
functional
(the other 64 may be employed
for direct silicon det. tests)
We are striving to get the entire system (FEB, SysCore, software)
packaged to allow shipment.
Starter kits in distribution
Teams from Colcatta, Kiew, Dubna, Dubna (MPD), GSI, Heidelberg were introduced
into running the starter kit with FEB and data chain at the GSI detector lab
CBM STS Workshop, Karelia, June 1 – 4, 2009
Complex Mulitlayer Data Chain


Detector
n-XYTER-FEB

n-XYTER

FEB and Bonding Technology
 Documentation
(Manual, newest version this May with update on parameter description)

ADC
 Interconnect

SysCore

Firmware
 Embedded software
 Soft configuration


Ethernet-Interconnect
PC and DAQ
Software design freeze 1.7, firmware, software, knut
Under heavy development (Anton Lymanets):
low level diagnostic toolbox for system analysis to make
successful deployment in other labs feasible

KNUT
 GUI
 DAQ System DABC
CBM STS Workshop, Karelia, June 1 – 4, 2009
Additional: Mimicing Triggered Mode of Operation

Discussions with Petr Nomokonov revealed a nice and simple
mode of forcing n-XYTER to operate classically in triggered
mode:

Switch chip to test trigger mode

Switch off test pulse enable
(important as would otherwise imply a special test mode)

 Test trigger signal will sample all signals during
monostable activity, window determined by "iota" parameter
120ns to several µs.

Alow to study noise all the way to the pedestal, where self
triggered normal mode of operation would drown in triggers!
CBM STS Workshop, Karelia, June 1 – 4, 2009
Test Trigger Mode alows globally triggered signal sampling
test trigger input in test trigger mode
comparator
charge
input
FAST
shaper 18.5 ns
peaking
charge
preamp
SLOW shaper
(2 stages)
140 ns peaking time
Time Walk
Compensation
circuit
trigger
timestamp reg.
PDH
reset
Peak
detector &
hold,
free running
dig. FIFO
pulse height
output
analogue FIFO
The DETNI ASIC 1.0, a front-end evaluation chip in AMS 0.35µ
CBM STS Workshop, Karelia, June 1 – 4, 2009
n-XYTER FEBs

FEB-Rev D: next version to implement all learnings

Relieve PCB specs by tightening bonding necessities and challenge

Chip-In-Board, two layer bonding and metal in-lay cooling contact

GEM-TPC FEB: ongoing dual n-XYTER for PANDA GEM-TPC

n-XYTER Quattro: STS-Baby-Sensor double sided readout 
towards a beam telescope

Mid-term: Hybrid development for demonstrators
(see Volker Kleipas talk tomorrow)

several n-XYTERs on Silicon-circuitboard
CBM STS Workshop, Karelia, June 1 – 4, 2009
n-XYTER Quatro: Double Sided Silicon Readout

Read-Out of double sided Si,
256 x 256 channels

First setup to occupy complete
capacities of one SysCore

Several Moduls may be set-up
to make a beam telescope

FEE of both sides live on one
potential!
 Rely upon readout-caps!
CBM STS Workshop, Karelia, June 1 – 4, 2009
n-XYTER Quattro

four chips bonded on one board
(Carmen Simons at GSI DetLab)

currently under tests

then:


bond a CBM baby sensor on one
side only and test

bond both sides and test
We will make 4 = 3 +spare
beam telescope elements for
September beamtime at GSI
CBM STS Workshop, Karelia, June 1 – 4, 2009
Feb Rev D, Layout – Start a new with Eagle Software
Enhance availability of starter kits

Eagle allows script based layout

Generate real footprint

Much easier to follow nets

Easily make bond-plan

Input pitch 5.4 mils = 137µ

Max bonding angle 22°

Max bond length 3.4 mm

Targeted but may not be ready for beam-time
CBM STS Workshop, Karelia, June 1 – 4, 2009
Preparation of Engineering Run (H.K. Soltveit)


Test Pulser

Identified very narrow line in test-pulse engine that introduces non-linearity of
pulser

Cal setting changes power consumption 0 to 10mW  implications to DC-level
in current prototype through Temp Coeff. of shapers
Discriminator was designed as "above pedestal trigger"


Temperature coefficient in shapers addressed:


 not linear over full threshold span i.e. S-curves are non-linear, explains
beamtime gain conundrum
modification gives 0.2 mV/K, down from 20 mV/K, simulated 50 to 90°C
Observed Monostable crosstalk identified and addressed
End of June 2009:
Engineering run schematics review meeting
End of July 2009:
Submission readyness review meeting
Then submission
Expect chips in Sept/Oct.
CBM STS Workshop, Karelia, June 1 – 4, 2009
Some In-Channel Discriminator Feedback Detected
...upon removal of discriminator-power decoupling
correlates with internal
discriminator trigger
correlates with external
test-pulse release signal (blue)
These issues are particularly important with the self triggered architecture!
They will be addressed even more in the next engineering run.
CBM STS Workshop, Karelia, June 1 – 4, 2009
Investigating Individual Channels, Triggerefficiency
Trigger efficiency in Treshold Scan: The S-Curves
used to be the technique to get analogue signal information w/o ADC
Derivative gives
image of noise!
This scale is not linear
with pulse height,
i.e. input charge!
- Input of test pulses at fixed rate,
- scan threshold while measuring detection rate
CBM STS Workshop, Karelia, June 1 – 4, 2009
Thermographic Analysis: n-XYTER in Action

Chip temperature around 70°C on FEB
with simple passive cooler

Digital readout and Time Stamp Clk
Distribution surprisingly the hottest part
CBM STS Workshop, Karelia, June 1 – 4, 2009
Conclusions

Starter Kits begin to become available

Feb Rev C+ fully bonded with SysCore

Feb Rev D  high yield, fabricatable FEB

Data chain went through extensive debugging phase, currently
software consolidating, tools for beam-time

Engineering run really in preparation, chips expected Sept./Oct.

many learnings addressed

future n-XYTER will be cured from child deseases and design-mishaps

black box operation much more feasible

n-XYTER on Silicon circuit board technology on the radar

parallel activity on CBM-XYTER development ongoing
CBM STS Workshop, Karelia, June 1 – 4, 2009
CBM STS Workshop, Karelia, June 1 – 4, 2009
New Detector Lab Facilities at GSI
Construction of the new GSI Detector Lab has commenced!
Located between GSI UNILAC and the CBM Offices (C27)

600 m2 of climatized cleanroom space with relative
humidity down to 20%

cleanroom class 10000 in general and better locally

dedicated bonding labs forseen

Additional 600 m2 available for detector testing, storage
and other activities

Additional 100 m2 of high clearance (10m headroom),
dedicated device setup space (detector integration and
tests)
CBM STS Workshop, Karelia, June 1 – 4, 2009
CBM STS Workshop, Karelia, June 1 – 4, 2009