# Presentation: 194875

## Liquid Argon TPC electronics for T962

**Carl Bromberg****Michigan State University****Largely the work of ****Dan Edmunds - engineer/hardware design****Phillipe Laurens - engineer/DAQ software**

**Dan Edmunds**

- Carl Bromberg

- T962 May '07

## PAB Program and Status

- Goal has been to develop DAQ electronics for a Large LArTPC
- Careful study of ICARUS (2 x 300 Ton) electronics
- Conclude that a multiple FET front end is unbeatable (if warm)
- ICARUS 10 year-old electronics design is obsolete and unavailable
- Commercial electronics suppliers are problematic - better to be in-house
- Develop an independent capability using modern components
- Testing Run II D0 hybrid preamplifiers (not in use, many available)
- MSU designed ADC-FPGA for Run II D0 trigger (2nd level spares)
- Single channel tests with simulated signals - intrinsic noise under control
- Make prototype preamp motherboards for a 96 channel TPC
- Mount a few channels (or boards) on the cryostat for noise evaluation
- See cosmic muon tracks in Argon before Spring 2007.
- Missed this target - causes: preamplifier housing design & safety reviews
- Electronics and DAQ are installed and readout has been tested.
- System noise is under control - ready for liquid.
- Afterward investigate COLD electronics: preamps, etc.

- Carl Bromberg

- T962 May '07

## Preamplifier and DAQ schematic 

- Carl Bromberg

- T962 May '07

## Hybrid preamplifier

- Dual FET input stage

- Output

- _D-zero Run-II LAr preamp_

- 2pF

- 20M

- Increase gain to 0.5 mV/fC
- Increase RC to 40 s
- Note: Signals are ~3 s

- Blocking now on preamp
- motherboard (PAB)

- 15nF

- Will improve
- low freq. cut-off

- _Modifications_

- Carl Bromberg

- T962 May '07

**Notes:**
Aerial view of the 4 mile circumference Tevatron collider.
Colliding protons and anti-protons  at two interaction points, CDF and D0  
Run I had 1E31 goal and exceeded by factor of 2.5. CDF acquired about 110 pb^-1 which was  the data set facilitating the top quark discovery. Data taking ended in 1996 for a 5 years upgrade period.
Run II upgrade another order of magnitude, factor of 5 by new pre-accelerator called the main injector and anotherfactor of two by a  permanent magnet anti proton storage ring called recycler
Bunch structure now is 36 on 36 with 396 ns time structure providing collisions of almost 2 TeV – the highest energy collider in the world before the LHC will turn on.
Run II’s high energy and luminosity CM energy will  push the high energy frontier of particle physics further. Physics goals are plenty and listed here and evidenced by the multitude of abstracts submitted to this conference.
The challenge of Run II necessiated a full upgrade of the collider detectors as well in order to cope with readout speed, radiation hardness, and capability to handle multiple interactions. 
The amibitious  goal of achieving instantenous luminosities of 2-4E32  is  challenging  and  sometimes frutrating race but just last week the milestone of 1E32 was finally crossed, just in time before the next shutdown. 

## Analog to digital conversion

- _D-zero Run-II ADF-2 card_

- _FPGA data storage field programmable _

- Example: 2048 samples @ 5 MHz (400 s total)

- Designed and built at MSU by Dan Edmunds

- Carl Bromberg

- T962 May '07

## Single Channel Test

- Carl Bromberg

- T962 May '07

## 22,000 electron simulated signal

- Capacitance 0-pf

- Capacitance 600-pf

- Signal to noise can  be estimated from these plots

- Carl Bromberg

- T962 May '07

## Noise spectrum

- 150 kHz

- Noise relative to 22,000 electron signal

- High pass & low pass filters are not optimized

- Conclude that noise in these preamps is low enough for now.

- OK to build a small system (~100 channels) based on these components

- Carl Bromberg

- T962 May '07

## Preamp Motherboard (PMB)

- for final Bias
- Voltage Filtering

- Preamp Hybrids

- Test pulse capacitor (8 ch)

- Decoupling Capacitors

- Post-amp filters and cable  driver

- to ADF2 card

- 16 channels on a  24 cm  x  23 cm board

- 0.33 F Capacitors

- Signal twisted pair

- RF shield box

- Carl Bromberg

- T962 May '07

## Other hardware

- Preamp Power Supply

- VME Crate with ADF2 card

- Carl Bromberg

- T962 May '07

## Installed in PAB

- Carl Bromberg

- T962 May '07

## Documentation

- Hardware is well documented
- Survey of state-of-the-art front end electronics
- Tests of D0 preamplifier hybrids
- Preamplifier modifications to optimize for LArTPC
- Preamp motherboards  <-->  ADF2 channel mappings
- Grounding and shielding principles employed
- Much more
- DAQ software is in use at PAB
- Run Control
- Raw data displays
- Simple data format (ascii files)
- Event selector - data plotting

- http://www.pa.msu.edu/~edmunds/LArTPC/
- http://lartpc-docdb.fnal.gov/ doc 235

- See -

- Carl Bromberg

- T962 May '07

## Battery powered “track” pulser

- Online displays look like this

- Recreated from offline data by Doug Jensen

- Each line is a single channel. 16 channels on each PMBoard.

- Two versions of PMB
-  Low freq. filter difference is obvious

- Noise RMS ~ 1-2 counts

- Carl Bromberg

- T962 May '07

## Doug’s “track” finder

- Carl Bromberg

- T962 May '07

## T-962 

- Now that PAB system has been installed and tested, the specifics of T962 electronics can be addressed
- Low noise systems need a CZAR. Control over anything connected to a region defined as electronics or DAQ.  If it generates noise (e.g., purity monitor, pulsers, level indicators, ...) -- it may need to be removed. Disconnecting from the exterior side of the feed-through may not be (or is likely not to be) sufficient.
- Dan & Phillipe are NOT free. D0 has paid for MSU electronics engineering services (design and operations) since the mid 80’s. LArTPC R&D has only recently obtained a fraction of these services (FY07: Dan ~ 5 months, Phillipe a few weeks). T-962 design and installation will need at least this level of FY08 funding.

- Carl Bromberg

- T962 May '07

## Approach to T-962 electronics

- The general principles of the design can be extracted nearly verbatim from existing PAB system documentation
- There are hybrids (caveats) and sufficient ADF2 modules for a  < 500 channel system. Other borrowed items can be purchased. Design proceeding on this basis.
- However, PAB tests already suggest modifications to improve performance and/or solve problems
- Feed - through design is made more difficult if bias voltage (~250 V) must be passed through to each wire
- Mass terminated signal cables can be used,  if bias voltage is not on the feed - through
- Each hybrid needs ~5  modifications (tiny surface mount parts)
- Commercial crates and higher density preamp cards can be used instead of existing homebrew mounting scheme
- PAB TPC will be available to certify modifications. They will be in the direction needed for larger LArTPC
- Schedule (realistic?) may not allow sufficient time to do the needed R&D.

- Carl Bromberg

- T962 May '07

## Cost and schedule

- Cost
- $10k in M&S was sufficient for the 96 channel PAB system, with many borrowed parts, and an engineer doing technician labor on personal time.
- The 500 channel system for T-962 can save on scale, but the missing labor must be provided.
- Realistically, a budgetary estimate of $50k in M&S is appropriate.
- A redesigned system could significantly reduce the cost but will likely impact the schedule.
- Schedule
- If the basic system were fully funded, with a minimum of changes to the design, the components could be assembled in 6 months. Installation in another 1-2 months. (well into FY08).
- A redesigned system, fully funded, could be installed in about 1 year.
- Improved estimates for cost and schedule can be provided in about 1 month.

- Carl Bromberg

- T962 May '07