TOTEM Collaboration Meeting June 2007 1 Total Cross Section, Elastic Scattering and Diffraction Dissociation at the LHC GEM and VFAT: H8 Test results GEM and VFAT: H8 Test results • Half Equipped Detector NoiseTest Half Equipped Detector NoiseTest • T2 Hybrids Noise Results T2 Hybrids Noise Results • H8 System H8 System Special thanks to Special thanks to Gueorgui Gueorgui , Emilio and Frederic that give us the , Emilio and Frederic that give us the possibility to acquire some data during the last test weeks! possibility to acquire some data during the last test weeks!
Transcript
TOTEM Collaboration Meeting June 2007
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Total Cross Section, Elastic Scattering and Diffraction Dissociation at the LHC
GEM and VFAT: H8 Test resultsGEM and VFAT: H8 Test results• Half Equipped Detector NoiseTestHalf Equipped Detector NoiseTest• T2 Hybrids Noise ResultsT2 Hybrids Noise Results• H8 System H8 System
Special thanks to Special thanks to GueorguiGueorgui, Emilio and Frederic that give us the , Emilio and Frederic that give us the possibility to acquire some data during the last test weeks!possibility to acquire some data during the last test weeks!
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THRESHOLD SCAN:THRESHOLD SCAN: Fast and full channel qualitative analysisFast and full channel qualitative analysis
TRIGGER S BITTRIGGER S BITVery fast analysisVery fast analysis
In the last test In the last test weeks we used weeks we used mainly mainly Threshold and Threshold and the S BIT toolsthe S BIT toolsfor the crash for the crash probability probability during the during the acquisitionacquisition
During the During the February tests February tests we verified for we verified for pads that a pads that a measure of the measure of the MEAN Y and MEAN Y and RMS Y of all RMS Y of all channel output channel output of the threshold of the threshold scan nearly scan nearly reflects the reflects the behavior of the behavior of the single channel single channel pulse calibration pulse calibration scan.scan.
The new The new fitting fitting procedure procedure works better works better than the than the previous one. previous one. Thanks!Thanks!
Noise ToolsNoise Tools
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Half Equipped Half Equipped DetectorDetector
Graph ID Sector READOUT Mean Y RMS Y V 5% Range V 1% Range
1 PS12 Pads 13.36 5.44 15-25 15-25
2 PS11 Pads 14.09 6.17 10-25 10-25
3 PS10 Pads 14.11 5.08 5-25 10-30
4 PS09 Pads 16.59 6.18 10-30 15-35
5 PS07 Pads 9.08 3.5 5-25 5-25
6 PS08 Pads (*)
7 PS13 Pads 14.17 8.29 10-20 15-40
8 EXT Ext Strips 32 0.1 32 33
9 INT Int Strips 18 2.3 18 20
* We changed this VFAT for readout problems (no sense output) 5% Mean Y
0
5
10
15
20
25
30
35
40
45
50
0 1 2 3 4 5 6 7 8 9 10
Chip Graph ID
PadsPadsVth 5%~[5-30]Vth 5%~[5-30]
Int Strips Int Strips Vth 5%~20Vth 5%~20
Ext Strips Ext Strips Vth 5%~35Vth 5%~35
We have obtained this lowest noise situation:We have obtained this lowest noise situation:
-shielding the chamber. -shielding the strips VFAT-TB cables.-making a direct gnd connection between strips Hybrid gnd and Chamber gnd
We tried also, without any improvement, to:-shielding the HV distribution board-connecting to gnd the last gem foil
Threshold ScanThreshold ScanResultsResults
We equipped a TripleGEM with 2 VFAT for Strips and 7 for pads.
We didn’t connect the HV to the chamber in all the following tests.
VFAT in the middle:It has VFATs on strips in one side and 50 ohm termination in the other side
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Threshold Meaning for GEMs…Threshold Meaning for GEMs…From: FEDCTOT05_SpecificationFrom: FEDCTOT05_Specification
0.045fC ~ 280 electrons0.045fC ~ 280 electrons
10Gevin Ar-CO2 (70-30) @ stp
Mean ~ 27Most Probable Value ~ 13 RMS ~ 30
We have then:We have then:Vth=30 -> ~8.4k electronsVth=30 -> ~8.4k electronsVth=50 -> ~14k electronsVth=50 -> ~14k electrons
Dynamical Range = 256 -> ~72kel.Dynamical Range = 256 -> ~72kel.
3030
5050 250250
As an example, to have this working As an example, to have this working range we need a TripleGem Gain of range we need a TripleGem Gain of 1.2k (if I didn’t stupid mistakes !?!)1.2k (if I didn’t stupid mistakes !?!)
TripleGEM GAINTripleGEM GAINEffectsEffects
MIP: first ionization clusterMIP: first ionization cluster
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Readout Configuration: Only one VFAT in pad sector PS12
Mean y Mean y @ 5%@ 5%
RMS y RMS y @ 5%@ 5%
Signal Range Signal Range
5%5%
[A] CAEN FLOATING POWER SUPPLY (+5V, +2.5V, +2.5V)[A] CAEN FLOATING POWER SUPPLY (+5V, +2.5V, +2.5V) 13.96 5.15 10-25
[B] CAEN FLOATING POWER SUPPLY (only 5V, 2.5V supplied from [B] CAEN FLOATING POWER SUPPLY (only 5V, 2.5V supplied from Regulators on TB)Regulators on TB) 12.69 7.63 10-35
[C] [C] LOCAL LOW VOLTAGE PS (only 5V LOCAL LOW VOLTAGE PS (only 5V , 2.5V supplied from Regulators , 2.5V supplied from Regulators on TBon TB) ) GND connected to Table GNDGND connected to Table GND
12.43 6.2 10-25
[A][A] [B][B] [C][C]
[A][A] [B][B] [C][C]
[5%][5%]
[1%][1%]
We achieved a good configuration with the local power We achieved a good configuration with the local power supply, but it seems that having the three power supply lines supply, but it seems that having the three power supply lines separated could be better (from pulse calibration scan separated could be better (from pulse calibration scan outputs).outputs).
We leave this local power supply because we were We leave this local power supply because we were interested to study the half equipped detector with this interested to study the half equipped detector with this one. Managing on the chamber (for example with one. Managing on the chamber (for example with shields) we restore a good level of noiseshields) we restore a good level of noise
Be careful because there are different scale. (I’m sorry..)Be careful because there are different scale. (I’m sorry..)
Low Low Voltage Power SupplyVoltage Power Supply
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Sigma Erf Fit behavior for partial equipped detector (2/3 VFTAs)Sigma Erf Fit behavior for partial equipped detector (2/3 VFTAs)BACKBACK
TOPTOP
OverOverStrips Strips ConnectionConnection
OverOverStrips Strips ConnectionConnection
[A]: Without Shields [A]: Without Shields VFAT on Pads (PS12) and Ext Strips (SS03)VFAT on Pads (PS12) and Ext Strips (SS03)[B]: With Chamber’s Shields[B]: With Chamber’s Shields VFAT on Pads (PS12) and Ext Strips (SS03)VFAT on Pads (PS12) and Ext Strips (SS03)[C]: With Chamber’s and VFAT-TB cables’ Shields[C]: With Chamber’s and VFAT-TB cables’ Shields VFAT on Pads (PS12) , Ext Strips (SS03) and Int Strips (SS04)VFAT on Pads (PS12) , Ext Strips (SS03) and Int Strips (SS04)
To obtain a good level of noise we have:To obtain a good level of noise we have:
Shielded the chamber (Top and Rear)Shielded the chamber (Top and Rear) Shielded the VFAT-TB CablesShielded the VFAT-TB Cables
PADSPADS EXT STRIPSEXT STRIPS INT STRIPSINT STRIPS
The first Shielding tests were made on partial equipped detector The first Shielding tests were made on partial equipped detector looking at the S1 Bit and collecting then some Threshold and looking at the S1 Bit and collecting then some Threshold and Calibration ScanCalibration Scan
To obtain the best noise level, with the half To obtain the best noise level, with the half equipped detector, we added also a shield equipped detector, we added also a shield over the connectors zone.over the connectors zone.
WE HAVE A LOT OF NOISE REDUCTION SHIELDING THE CHAMBER, BUT TO WE HAVE A LOT OF NOISE REDUCTION SHIELDING THE CHAMBER, BUT TO DEFINE WHICH SHIELD IS REALLY USEFUL WE NEED TO WORK IN A MORE DEFINE WHICH SHIELD IS REALLY USEFUL WE NEED TO WORK IN A MORE CLEAN CONDITION….see VFAT-TB cables effects.CLEAN CONDITION….see VFAT-TB cables effects.
Shielding TestShielding Test
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HALF EQUIPPED DETECTOR Noise Test ObservationsHALF EQUIPPED DETECTOR Noise Test Observations
Not Scanned VFAT Threshold:
Pads=50 Strips=50
Not Scanned VFAT Threshold:
Pads=30 Strips=50
Changing the threshold of VFATs that are not scanned, you see effects on the scanned VFAT.Changing the threshold of VFATs that are not scanned, you see effects on the scanned VFAT.
Threshold Scan on Threshold Scan on External StripsExternal Strips
We can see this injection of noise from the scanned VFAT into the other strips/pads looking at the cumulative plotsWe can see this injection of noise from the scanned VFAT into the other strips/pads looking at the cumulative plots
Threshold Scan on Threshold Scan on External StripsExternal Strips Internal Strips [Th=50]Internal Strips [Th=50]
Pads [Th=50]Pads [Th=50]
Large Pads under External StripsLarge Pads under External Strips
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STRIPS THRESHOLD SCANSTRIPS THRESHOLD SCAN
External StripsExternal Strips
We found for strips situation in wich all channels seem to move We found for strips situation in wich all channels seem to move nearly together.nearly together.
HALF EQUIPPED DETECTOR Noise Test ObservationsHALF EQUIPPED DETECTOR Noise Test Observations
THRESHOLD SCAN ON THE EXTERNAL STRIPSTHRESHOLD SCAN ON THE EXTERNAL STRIPS
We change one VFAT on Pads and we move Vfat-TB Cables
We change the twisted Vfat-TB Cable for strips with the green one
Some example of VFAT-TB cable connection (moving, replacing) effectsSome example of VFAT-TB cable connection (moving, replacing) effects
A next step could be to make all these noise studies in a more clear and simple situation than in the “aquarium” (on a table for example, where should be easiest the control of gnd, cable, etc etc).
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S1S1
AVDDAVDD
S1S1
S1S1
AVDDAVDD AVDDAVDD
S1S1
DVDDDVDD
S1S1
DVDDDVDD
2.5V Analog2.5V Analog
2.5V Digital2.5V Digital
VFAT POWER SUPPLY MONITORINGVFAT POWER SUPPLY MONITORING
We tried to supply the chip with bigger cables directly from the TB, without any improvement.We tried to supply the chip with bigger cables directly from the TB, without any improvement.We change also the local power supply with the CAEN Floating one, but we found the same behaviour. We change also the local power supply with the CAEN Floating one, but we found the same behaviour.
~ 5% of variation~ 5% of variationin an/dig power in an/dig power supply linessupply lines
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Only one Pads Sector On Only one Pads Sector On (Threshold scan on Pads)(Threshold scan on Pads)
Only one Strips Sector On Only one Strips Sector On (Threshold scan on Strips)(Threshold scan on Strips)
Only One Pads and One Strips OnOnly One Pads and One Strips On (Threshold scan on Strips)(Threshold scan on Strips)
Pads [fixed Threshold 50] (we have a lot of noise in the
DIGITAL AND ANALOG GND CONNECTION ON THE CHIPDIGITAL AND ANALOG GND CONNECTION ON THE CHIP
•VFAT NOT PLUGGED ON GEMVFAT NOT PLUGGED ON GEM:
Results from Pulse Calibration Scan:
-Digital/Analog GND CONNECTEDCONNECTED on the chip Sigma of the ERF fit between 4 and 6between 4 and 6
-Digital/Analog GND NOT CONNECTEDNOT CONNECTED on the chip Sigma of the ERF fit between 1.5 and 2between 1.5 and 2
These results are in contrast with the VFAT test results obtained in lab. Possible explanation of this inconsistency could be:
-Different GND Configuration (The various GND configuration are listed in the following pages). The GND configuration in the test beam zone it is not so good as could be in lab.
-Different Cable length between VFAT and Transition Board
-…
•VFAT PLUGGED ON GEMVFAT PLUGGED ON GEM:
No evident benefitsNo evident benefits on having the Digital/Analog GND NOT CONNECTEDNOT CONNECTED on the chip (in some configuration seems also to be worse). Anyway, we don’t have an accurate investigation on this point because we have understood that the final hybrid should be, without any chance of modification, with An-Dig Connected.
Hybrids TEST: Comparison between hybrids V2 with and without separate Hybrids TEST: Comparison between hybrids V2 with and without separate An. and Dig. GNDAn. and Dig. GND
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FEC errors codeFEC errors code: 250,210,.. Normally we have found difference between write and read like : 250,210,.. Normally we have found difference between write and read like
… … 0 1 0 0 …0 1 0 0 …
… … 0 0 1 1 …0 0 1 1 …
writewrite
readread
Frederic put a patch that permit to us to use GUIDebugger and Frederic put a patch that permit to us to use GUIDebugger and VFATDebugger.VFATDebugger.
It could be better if we could also upgrade the acquisition Software in It could be better if we could also upgrade the acquisition Software in the same way, i.e. to try again (and not crash) for n times if it find these the same way, i.e. to try again (and not crash) for n times if it find these kind of errors.kind of errors.
H8 System – I2CH8 System – I2C
Control Loop: Control Loop: Problems disappeared when Geourgui swapped the two DOH Problems disappeared when Geourgui swapped the two DOH
Sucessfully opened a FEDkit receiver with FPGA version 0x3f00002a
Failed while trying to set receive pattern. Reverting to default.
. 0x000000000000f7f7
. 0x0000000000000000
K 0x50c800c700c600c5
. 0x000000000000f7f7
Data File Start with Data File Start with the right headerthe right header
Monitor OutputMonitor OutputOK!OK!
Data File Start with Data File Start with the wrong headerthe wrong header(for OptoRX buffer (for OptoRX buffer problems)problems)
Monitor OutputMonitor Output ZERO DATA FILES ZERO DATA FILES
(only for the monitor!)(only for the monitor!)
We solve this problem turning off/on the power supply of the optoRx but possible solution cuold be:We solve this problem turning off/on the power supply of the optoRx but possible solution cuold be:1- Ask to the monitor software to search for the right header and packet length1- Ask to the monitor software to search for the right header and packet length2- Ask to the acquisition software to send a “clear buffer”command before the acquisition start 2- Ask to the acquisition software to send a “clear buffer”command before the acquisition start
H8 SystemH8 System
ZERO DATA FILESZERO DATA FILES
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Possible very first steps to done on noise analysisPossible very first steps to done on noise analysis
•Refine the gnd configuration in H8. We have to find the Paul’s result for the VFATs not Refine the gnd configuration in H8. We have to find the Paul’s result for the VFATs not plugged on the detector.plugged on the detector.
•Realize a simple and temporary horseshoe card (only for the powering and grounding Realize a simple and temporary horseshoe card (only for the powering and grounding the VFATs on the detector). We could try to supply the chip without passing from the the VFATs on the detector). We could try to supply the chip without passing from the TB.TB.
•Repeat some of the tests done in a more clean situation (lab and/or table in H8).Repeat some of the tests done in a more clean situation (lab and/or table in H8).We have for example to accurately check:We have for example to accurately check:
•Which shield on the chamber/cables is really useful.Which shield on the chamber/cables is really useful.•The VFAT-TB cables effects, to avoid mistakes in the interpretation of data.The VFAT-TB cables effects, to avoid mistakes in the interpretation of data.
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