Partecipants:
Nicola Canci, Giuseppe Matteucci, Riccardo de Asmundis, Peter Skensved, Marisa Gulino, Mauro Caravati, Bianca Bottino, Giuliana Fiorillo, Grigory Dolganov, Alessio Caminata, Dmitrii Rudik, Francesco di Capua, Gabriel Botogoske, Gianfrancesco Grauso, Marco Rescigno, Sebastiano Albergo, Roberta Calabrese, Simone Sanfilippo, Sosuke Horikawa, Yury Suvorov
17:05 Start of the
GM: Gennaro has started working on the integration of the instruments that I've shown last week. The task is well within time.
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17:10 Gabriel Botogoske - Camera Integration
The camera that we're using in Proto-0 is a USB Revotech, of 3Mpx. I've tested it and it works perfectly. We have a USB TypeA FeedThrough for communication. A heater is placed inside the casing of the shell to warm up the camera. Together with Nicola, we have identified a simple mechanical piece to adapt the camera to our mechanical structure. I have tested the illumination system (LED + Resistor) in an extreme condition, in LN2 for three hours, and it still works properly, even if a higher voltage is needed (7 V vs 4 V in cold). I have managed to readout the camera feed via a python package: opencv. Next step is integration.
NCC: I see only four LEDs in your slides. Are those enough?
GB: I will test this and modify the illumination system accordingly
PS: Are you going to spread out the LEDs or keep them close to the camera?
GB: We will see depending on the test
GM: Is the support structure ready? How much time do you foresee to finish this work?
GB: We have a piece that needs to be adapted. We can do it ourselves. I foresee two weeks to have everything ready.
MC: Where are you pointing at with the camera, inside the cryostat?
GM: The plan is to observe the bubbler, where the gas comes out of the diving bell.
MC: Very good, that is a very interesting location.
BB: I suggest you use a commercial white LED strip. You can attach it to the top flange.
NCC: Let's avoid any model with an adhesive, it may interfere with purity of LAr.
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17.27 Grigory Dolganov - Field Simulation in Proto0
Difference between 2D/3D simulation: in high enough detectors (>~ 10 cm) with constant section (Proto-0 applies) 2D simulation is fine. 3D simulation is needed to determine electric field in the corners, to account for any asymmetrical parts, to study the electric field between TPC and cryostat. To get the same accuracy of a 2D model (run in 1 minute) a 3D model needs hours of computations. I choose the first ring values to make the electric field uniform inside the reflector cage. The field strength above the wireframe is acceptably uniform. Corners are hard to simulate because the simulation treats the Clevios as a 2D plane.
Then, let's discuss what happens when I remove one wire from the grid to recreate. The absence of one wire leads to a very strong field non-uniformity, with a very large leakage. This result in a 9% less extraction field next to the missing wire.
GF: Is the grid that we have the same dimensions of that in the drawings?
GG: The drawing is that of Yi.
PS: You can use the springs that Bruce developed for just the single missing wire. That way the wire length is no longer critical
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17.55 Riccardo de Asmundis - Updates on the Slow Control
I've reported the stability of sensors with an empty system, except for the vacuum gauges. I'm now updating the slow control software. Before the cryogenic test programmed for the end of April I have to check all signal lines and I need to implement the new parameters in the synoptics of the control system. I need a person to assist me for a couple of hours: GG?
GF: Is the AL300 in your list?
RdA: Not explicitly - the new instruments are not yet configured to the network.
GF: Refer to Yury.
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18.05 Wrap up
NCC: Does anyone have further comments?
SH: I don't have any big update on the capacimeter. Let me just clarify that we will provide also the power supply that is needed to control it.
GM: Does it need to be integrated in the slow control / midas?
SH: You may want so, if it ends up causing noise. Or you unplug it manually.
GF: Let's add the remote controlling of the PS as a requirement. Also, please Sosuke, prepare a document with the specifications of such device. We need a place to share documentation. Please GM provide such place.