Derecho a una Vivienda Adecuada y Digna

For the moment the CE consortium does not have a formal substructure with coordinators ap- pointed to oversee specific areas. This is in part due to the current focus on ASIC development; informal subgroups exist that are following the design of the various ASICs. A BNL collaborator is currently leading the design of the new version of LArASIC, and in parallel following the studies of commercial ADCs for SBND, which is using the same ASIC. Collaborators from LBNL, BNL, and Fermilab are working on the design of a new ADC ASIC with 65 nm technology. Collaborators from Fermilab and SLAC, respectively, are overseeing the development of the new COLDATA ASIC and the adaptation of the nEXO CRYO ASIC for use in DUNE. A new working group is tasked with studying reliability issues in the CE components and preparing recommendations for the choice of ASICs, the design of printed circuit boards, and testing. This working group will consider past experience from cryogenic detectors operated for a long time (ATLAS LAr calorimeters, NA48 liquid krypton calorimeter, HELIOS), from space-based experiments (FERMI/GLAST), and the lessons learned from ProtoDUNE-SP construction and commissioning. Input from other fields will also be sought. Later this working group will develop the QC program for the CE detector com- ponents, starting from the ProtoDUNE-SP experience. It is planned to reassess the structure of the group in a few months, with a likely split between components inside and outside the cryostat, a new group responsible for testing, and various contact people for calibration, physics, software and computing, and integration and installation.

The main decision that the consortium has to face in the next 12 to 18 months is the choice of ASICs to be used in the DUNE FEMBs. A first decision will be taken early in Summer 2018, when it will be determined whether or not system tests, beyond those planned by the SBND collaboration, should be performed for commercial ADC chips and for the ATLAS ADC. In February 2019, following tests performed with a ProtoDUNE-SP APA in the cold box at CERN and with a small TPC in LAr at Fermilab, a list of options will be prepared for presentation in the TDR. Only ASICs that satisfy the DUNE performance and reliability requirements will be included in this list of options. A final choice for the ASICs to be used in DUNE should be taken in summer 2019, prior to the DOE CD-2/CD-3b review. Physics performance, reliability, and power constraint considerations will be taken into account when making this choice, which will go through the Executve Board approval procedure.

3.9.2

Planning Assumptions

Plans for the CE consortium are based on the overall schedule for DUNE that assumes that the first anode plane assemblies will be fully populated with electronics and tested in spring 2022, with the installation of the anode plane assemblies inside the cryostat beginning in May 2023. Plans are being made for replacing three of the six anode plane assemblies of ProtoDUNE-SP with the final DUNE anode plane assemblies including final ASICs and FEMBs, and for a second period of data-taking in 2021-2022. The integration of the anode plane assemblies for the first cryostat with the electronics should be finished by October 2023, and their installation in the cryostat by January 2024. This requires integrating two anode plane assemblies per week over a span of 21 months, which allows for a ramp-up period at the beginning and a contingency of two to three months at the end. This defines the time window for the completion of the R&D program on the ASICs. A set of ASICs (or a single ASIC) meeting all the DUNE requirements has to be fully qualified by fall 2020, such that pre-production ASICs and the corresponding FEMBs can be assembled and tested in spring 2021, launching the full production in summer 2021.

Meeting this timeline requires that the development of the ASICs, and in particular of the newly designed ones (the SLAC CRYO ASIC, the joint LBNL-BNL-Fermilab cold ADC, and COLDATA) are prototyped by the end of summer 2018, with testing completed by the end of 2018. This would allow for a second round of prototyping, if necessary, in the first half of 2019. It also leaves room for a possible third design iteration and qualification of ASICs and FEMBs between the end of 2019 and fall 2020. The FEMBs used for ProtoDUNE-SP will likely have to be redesigned to house a new ADC and to replace the FPGA used in ProtoDUNE-SP with the COLDATA ASIC. Multiple variants of this board will be necessary, depending on the success of the various ADC R&D projects being currently pursued. These design changes will be made in the second half of 2018. Additional FEMB prototypes will be designed and fabricated depending on the outcome of the initial testing of the SLAC CRYO ASIC. A second iteration of FEMB prototype(s) will be necessary in 2019, when the final ASICs (that may have a different channel count from the first round of prototypes) will become available.

It is assumed that apart from the ASICs, where rapid development is still required, and the FEMBs, which have to be redesigned to accommodate the new ASICs, most of the detector components to be delivered by the CE consortium will require only minor changes relative to the ProtoDUNE-SP components. For this reason the modifications of these other detector components will be delayed until 2019 or 2020, which will also help with the funding profile. Exceptions will be made for further development in test stands, for cabling studies, and for conceptual studies of automated testing assemblies, rack space assignment, and the interface to the DAQ system.

3.9.3

WBS and Responsibilities

A preliminary work breakdown structure (WBS) has been prepared for the activities of the CE consortium. The WBS is split in a time-ordered fashion between activities related initially to design, R&D, and engineering, then to production setup, and finally to the production, integration, and installation phases for the SP module to be installed in the first DUNE cryostat. The latter

three sets of activities could be repeated for the construction of additional SP modules. Physics and simulation activities are to proceed in parallel to the detector design and construction activities. Within each phase (starting with the design and ending with the installation), the WBS foresees work packages that cover system engineering, installation of the detector components inside the cryostat (including all ASICs, FEMBs, cables, and corresponding support structures and cryostat penetrations), and the detector components installed on top of the cryostat (including the warm interface electronic crates with their boards, the LV and bias-voltage power supplies with their crates, and all of the associated cables and infrastructure). This matches the current plan for the future group structure of the CE consortium. In addition, a separate work package covers the development and support of the testing facilities and the related software in order to provide these activities with the effective supervision that is required in order to meet the reliability requirements of the DUNE experiment.

All of the institutions currently interested and committed to the construction of the detector components that are a responsibility of the CE consortium are from the USA and are supported by a single funding agency, the Department of Energy. For this reason, the exact role of the individual institutions in the activities of the consortium has not been defined, except for the currently ongoing ASIC development. The role of each institution will be defined prior to the submission of the TDR.