Minutes of the forward endcap EMC eZuce SRN meeting, 2nd of July 2018, 14:00-15:00
Bochum: Cathrina, Jan, Malte, Matthias, Miriam, Tobias T., Tom
Bonn: Christoph, Ulrike
Giessen: Hans, Markus
VPTT Submodule Production:
Submodule production is ongoing with high throughput (4-5 submodules per week)
Two more damaged VPTTs: one tube with loose dynode grid (2nd time this occurs), one tube with damaged pumping port (loss of vacuum)
For replacing the damaged tubes we decided to not force a new matching with the current constraints but to replace with reasonably close measuring tubes (gain, skb, gain change with HV)
A list of measured tube gain changes as a function of the high voltage applied will be prepared by Christoph within this week
1st regular delivery day is August 28th: 5 boxes (5 submodules) will be shipped to Bonn by the Bochum University "Fahrdienst", an appropriate transportation insurance is contrated (also covering transportation from Bonn to Juelich)
Transportation to Juelich has to be worked out in detail; a transport of cosmics tested units from BN to JUL on the same day as delivery of new build units from BO to BN is obvious. However, delivery to a radiation controlled area on a secured research center site is probably some more complicated...
We will discuss this at an onsite meeting in Juelich where also the submodule storage situation in the TOF hall will be clarified
SADC Crates: Signal Cable Connection
A design of the signal cable connection to the SADC crate backplane was presented by Christoph
Pawel mentioned, the design has to be adopted to the crate 'rail' design of leading and supporting the cable-to-plug pcb (extension of pcb on top and bottom)
APD HV Regulation:
Christoph presented different pattern of HV distribution within one submodule and its implications in case of a HV input failure (corresponding to 8 regualted channels)
Would a continues failing region or several spots of single APD failures to be preferred?
We saw no real reason to decide for a specific schema. Hans mentioned the low probability of such a total HV input failure or the need of swiching off the input.
Staying with the one pattern already worked out by Christoph would save any further man power on this topic
A first batch of screened APDs was sent to Giessen
Irradiation may occur this week as long as the radiation officer in the Strahlenzentrum is available