Reworking on LTOF and tests with the EM electronics

1
Reworking on LTOF and tests with the EM
electronics

• V. Bindi
• INFN Università di Bologna

2
Outlines...

• Reworking on the Lower TOF
• EM electronics integration in the LTOF
• New functional tests with VME set up

3
LTOF Reworking
After TVT and Vibration tests of the FM LTOF some
reworking has been necessary 1) one of the 4
on-board SFEC cards for Dynode read-out, had
communication problems, identified as a bad
soldering in two adjecent Actel pins. The Actel
was easily accessible and the card has been
repaired.
The two sides of the SFEC on-board Card reading
20 single PMT Dynode signals.
4
LTOF Reworking
2) We replaced the QM version of the patch-panels
with the proper flight Aluminum patch-panels.
One of the four flight patch panels
3) All the apparatus has been grounded.
4) The removable covers giving access to
internal cabling, cards and PMTs will be
sealed after completion of all tests in CERN and
before integration.
5
EM electronics integration in the LTOF First
step integration of the HV power supply
The LTOF is inside a laminar flux dark chamber
A SAVER PANEL for Anode and HV signals has been
installed.
6
EM electronics integration in the LTOF First
step integration of the HV power supply
The SHV-EM electronics to power the Hamamatsu
R5946 PMTs has been set up and is now running.
1 the QM SHV brick 2 the saver panel 3 the EM
SPD cards 4 resistor bench 5 the EM SDR2
card 6 the EM Backplane
2
3
4
1
5
6
7
First step Integration of the HV power supply
The software implemented by A.Lebedev was used
to monitor and manage the HV Brick.
Second step integration of the SFEC on-board
cards
Acquisition of the Flight SFEC cards through SPT2
by SDR2
8
New functional test VME set up A standard VME
electronics data acquisition set-up has been
integrated

• to validate the Flight electronics,
• to characterize the detector.

9
New functional test VME set up
A telescope with two AMS-01 counters has been
implemented to provide an external trigger for
both lower TOF planes.
10
New functional test VME set up The VME data
acquisition set-up is a flexible system using the
LabView software
The LabView project
The graphics interface
11
New functional test VME set up This set up
allowed us to compare the m.i.p. Anode signal
peak of the ADC of the SFET/SFEA prototypes with
a well known VME ADC in order to validate the
chip response.
The calibration of some ADC SFET/A prototypes
channels in pC. The obtained calibration
coefficient is of about 0.74 pC/ch.
12
New functional test VME set up The calibration
coefficient dispersion of the chip channels is
within 10.
13
Counters working conditionsFinal settings

• Up to now, during the TVT and the vibration tests
  we powered all the PMTs at standard high voltages
  of 1950 V, 2050 V, 2150 V.
• Before bringing the LTOF at CERN the first half
  of June, we want to
• perform the final equalization of counters,
• calibrate the on board SFEC channels
• refine the working PMT HVs.
• The LTOF will come at CERN with all working
  conditions set, ready for the integration with
  the flight electronics.

• The new VME set up allow us to find for each PMT
  the minimum operating HV giving us full
  efficiency, because we want to have the maximum
  harm as possible to optimize the detector
  response with the magnetic field on.
• For the moment we simulated two types of flight
  conditions
• the control of the SHV regulating cards failure,
  this means that all channels work at 1950 V.
• the failure of one SHV channel per side per
  counters.

Actually we are verifying that in both
situations we dont loose efficiency.