Minutes of the forward endcap EMC eZuce SRN meeting, 2nd of July 2018, 14:00-15:00

Presence:

• Basel: -
• Bochum: Cathrina, Jan, Malte, Matthias, Miriam, Tobias T., Tom
• Bonn: Christoph, Ulrike
• Groningen: -
• Stockholm: -
• Uppsala: Pawel
• Giessen: Hans, Markus
• GSI: -

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

APD Screening:

• 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