Minutes Run IIB Silicon Sensor Meeting,
These minutes can be found at:
ü News / Status George / Marcel
ü Action Items George, Marcel
ü Status Database Stu Fuess
Test structure results
ü L1 C's Mme. Mao, Marcel
ü APS RunIIb Practice Talk Gustavo Otero
Action Items (George, Marcel)
keep our momentum and focus our efforts a few schedule activities have been
elevated to action items. The following six activities have been agreed upon by
the group as being action items to be completed as much as we can by early
July. The names in parentheses are those who have taken responsibility for the
task. If a schedule date is indicated, the first date is the current schedule
date, based on the schedule as statused in February and the second date is the
original Lehman schedule date from September ’02.
Layer 1 Structure:
sector test with 3-6 sensors with Saseq readout (Andrei)
1. full set of noise, grounding and HV studies
finalize layer 1 hybrid design (Schedule: PRR
3. finalize layer 1 djc
simultaneous readout of 3 modules
Layer 0 Structure
populated with 3-6 sensors with Saseq readout (Kazu)
1. full set of noise, grounding and HV studies
finalize layer 0 hybrid design (Schedule: PRR
3. perform all analogue cable tests
finalize layout analogue cables (Schedule: PRR
finalize layer 0 djc (Schedule: PRR
simultaneous readout of > 2 modules
Stave (Andrei and Bill)
1. Simultaneous full chain readout of 4 modules in a stave with SASEQ
Noise, grounding and HV studies (Schedule: PRR
3. finalize readout module fixtures
4. finalize stave assembly fixture
5. Thermal studies, stave will be cooled
6. Try to readout with 1% Test
Finalize stave design and PRR
4. All test stands ready (Cecilia)
Start routine burn-in of modules and hybrids
released for production (Kurt)
6. Database fully functional (Offline Support)
Cooling issues with the layer 0 and 1 support structures are still being discussed.
o Another action item, though on a later timescale is
1% and 10% Test Stands
(Sergey, Linda, Kristian)
1. finalize AC design: terminations, voltage regulation, AC PS issues
2. clock regeneration
3. stable readout of hybrids/modules through the Purple Card
4. stable readout of hybrids/modules through the full chain
5. tests of WIENER PS : load tests, voltage regulation test
6. First pass monitoring software
Database (Stu Fuess)
was not at the meeting because of spring break. However, the online support
group has a first pass database available for us. They request feedback. Stan
has installed an initial version of the silicon detector production database
based upon the Atlas model. This
has been done using what is available on the web. The ATLAS people have
officially signed off on us using their database and they will switch to the
most recent version of the ATLAS database.
In detail, Stan "reverse engineered" the "data description language" (ddl) file found on the web and created a model of the database within Oracle Designer. With Designer, Stan has created an Entity Relationship diagram: http://d0server1.fnal.gov/projects/Online_Computing/Projects/SiDetDB/sct2.pdf
Designer can then create the SQL statements necessary to actually build the ORACLE database. Stan has added comments to this SQL file to describe, to the best of his knowledge, the fields within the database. Along with the ER diagram, this descriptive text is "our" knowledge of the database structure. The SQL file is:
People are encouraged to look at the ATLAS documentation
The actual ORACLE database has been created on the D0 Online development platform. Anyone wishing direct access to the database (e.g. to execute SQL queries) will need to request (email@example.com) an Online account. Once the development cycle slows we will move the database to the D0 Offline platform.
The offline support group needs input from the SiDet experts and users!
Which tables/fields within the ATLAS structure are relevant? Where should they initially focus effort? What data exists to be inserted into the database, and in what form? What query tools are needed? Basically, they need lots of "requirements" and "use cases". As mentioned before, Eckhard is the silicon liaison with the database group. Please provide the online support group, through Eckhard, examples of how you expect to be able to use (input and output) the database. This is a critical need before any more progress can be made. Eckhard also made a plea for an update of the sensor QA document so that it can be used to guide the database development. Lisa expressed concern about the format of testing results and how results were going to be uploaded into the dabatase.
Layer 1 Test Structure
o Frank described the measurements done at Zuerich on the layer 1 test structure that he has. The depletion voltage of the planar diode on the test structure was measured. It is about 5-10% higher than for the strip detector which is expected. The coupling capacitance was measured to be 14.8 pF/cm, with a breakdown above 200V. Frank also measured the resistance of the Al ‘snake-like’ trace on the test structure. It has a higher resistivity than expected. This is exactly the same as was also observed by Mme. Mao at Fermilab on the layer 2 test structures. As also on the outer layer test structures, there are numerous arrays of polysilicon resistors and it is not clear what the difference is. In any case, the value of the poly-silicon resistor on the baby sensor is within specs. The total load capacitance was measured on the baby sensor and the same frequency dependence as for the outer layer sensors was observed. The interstrip capacitance derived from the measurement does not exhibit a maximum in the frequency dependence and gives a value of 0.39 pF/cm to each neighbor. Also the MOS structure was measured, but the characteristics are not yet fully understood.
Layer 1 Capacitance Measurements (Mme. Mao, Marcel)
o More capacitance measurements were performed at Fermilab with an eye to understanding the frequency dependence. Sensor # 1 was measured in exactly the same configuration the outer layers were measured. The observed behavior of the sensors is identical. The capacitances, total load, interstrip and capacitance to backplane, show exactly the same frequency behavior as the outer layer sensors. The measurement followed an older version of the QA document and had the bias voltage on neighboring pads. It was repeated with no bias on the neighboring pads and less of a frequency dependence was observed. The values approached a constant capacitance asymptotically. This should be looked at in more detail.
o The important point, however, is that the results on the test structure measurement at Zuerich and the measurements at Fermilab on the sensors are all consistent.
Update Irradiation (Tim Bolton)
o Tim presented an update on the dosimetry verification at KSU. A cross check using Copper foils has been used to measure the total flux. The basic idea is that both stable isotopes of Cu can be excited to long-lived Zn isotopes that decay via positron emission or electron capture with accompanying gamma rays back to copper. The cross sections for these reactions are very large The preliminary results indicate that the activation analysis performed with the foils gives the same answer as the direct flux calculation. The ratio of the two is 0.9 with a 15% uncertainty. Some further cross checks are to be performed and then it will be written up.
o The discussion then concentrated again on the conversion to 1 MeV neutrons. Frank pointed out, again, that it would be good to plot the results directly as function of proton fluence without any conversion entering.
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