FAQ for the implementation of the ECFA detector R&D roadmap for quantum sensing.

1) What are the goals?
ECFA is encouraging an implementation of the roadmap for detector R&D; this implementation focuses on Quantum and Emerging technologies.

The implementation is two-fold: one one hand, it will take the form of a to-be-formed world-wide collaboration ("DRD5", also known as "RDq") which will focus on carrying out the various quantum sensor technology R&D projects ("work packages") that will form part of a common proposal. This to-be-formed collaboration is intended to be a world-wide entity of groups working on developing the technologies relevant for bringing Quantum Sensing to particle physics (low and high energy); we forsee that there will be no entrance fees or annual contributions, and that the only obligations groups joining this effort commit to is to be available to evaluate ideas in their area of expertise for other groups in the collaboration (and of course to share responsibilities for contributing to the development of any technology R&D they agree to work on in common with others).

On the other hand, this same collaboration will prepare a proposal that will be submitted to a new CERN body, the Detector R&D Committee (DRDC) that will evaluate the scientific and technological merits of a number of detector R&D work packages while ensuring that those are congruent with the recommendations of the ECFA roadmap.

2) To what extent should the proposals be guided by CERN's existing activities? In other words, should they specifically consider how they could leverage the resources CERN already has in place to develop the technology they're thinking about?
The goals are much more wide-ranging than CERN: the ECFA roadmap on Quantum Sensing targets detector R&D for "particle physics", which means also activities in labs (including University labs) around the globe. "Particle physics" should be considered as anything covered by the ECFA roadmap, so from field measurements (in the case of very light mass axions) all the way up to traditional high energy physics devices. The groups involved in the proposals as members of the to-be-formed RDq collaboration will need to collaborate with each other, will need to find funding, and so will need to see their own interest in pursuing the projects that they will hopefully sign up to (as co-signataries of the RDq proposal and members of the RDq collaboration).

3) Is CERN looking in particular for technologies to "scale up" -- so should it have some clear path where doing something more at the CERN scale as compared to an individual laboratory scale offers clear advantages?
The effort is not CERN specific. Rather, the goal is to identify areas in which concerted technology R&D could benefit "particle physics" as a whole, and of attempting to form a spread-out effort to address that R&D. Good if it impacts HEP, but that's not a necessity. R&D on, e.g. tuneable SC RF cavities for low-mass axion searches could fit the bill just like development of novel ionic systems (i.e. fully stripped HCI's with a single electron in a Rydberg orbit) or stacks of TES pixel arrays as novel trackers for micro-charged particles. Scalability challenges might well be part of the picture, but that's not a necessary ingredient.

4) Is CERN offering state-of-the-art laboratory space to host the experiments, so that R&D could be done at a level infeasible in a university laboratory setting?
In some cases, yes (wherever CERN groups might end up partnering on specific technology R&D), but generally, no. The idea is that much of the R&D is carried out among RDq collaboration institutes (including national or even international labs) at locations around the globe. CERN might then provide a specific service, such as expertise that it might have or access to test beams, but carrying out all the hoped-for R&D at CERN (with furthermore CERN providing the commensurate high-tech equipment) would far exceed CERN's possibilities.

5) What are the next steps?
Currently, a group of ~30 convenors (around 5 per sensor family) are discussing among themselves and their respective communities, but also integrating submitted proposal ideas (1-2 pages) for specific detector R&D, in order to identify those areas with the largest interest and potential impact. The call for submissions (please feel free to send those to either michael.doser@cern.ch or demarteau@ornl.gov) is open until mid-March. These ideas and proposals for detector R&D were discussed at a workshop (attendence limited to the convenors) in early April, and forms the basis for a first LOI (under preparation for submission by end of July by the convenors and the coordinators), which be evaluated by a new CERN committee, the DRDC that is being put together right now. At this point, individual groups will not need to sign or commit to be involved, but expressing their interest and support can help advance the process and will underline the broader communities' intention to be involved.

The second half of the year will focus on two aspects:
- the formation of the DRD5 / RDq collaboration, whose detailed structure is still being defined, but with the goal of having a formal structure, including a memorandum of understanding with CERN, in place by the end of the year. Membership in this collaboration is contingent only on the willingness to contribute to the subsequent quantum sensing R&D process in the coming years.
- and the writing and submission of a formal proposal (to be submitted by the end of the year) by the to-be-formed new DRD5 collaboration, with a number of quantum sensor R&D work packages.

This second part will be much more open than the steps leading up to the LOI, and foresees an open forum (a workshop at CERN from October 2-4) in which all participants in the process are involved, with the goal of fine-tuning the scope and focus of the proposal's work packages, but also to identify potential contributions. Naturally, at that point, no firm committments can be made, but groups should definitely indicate their expected levels of involvements in the work packages of the proposal.

Bottom line: with no firmly allocated resources, no explicit funding, no specific location and no teams (for now), we're trying to define a set of quantum sensor-related technology development goals that the respective communities consider would be helpful to them and that could - under the umbrella of the ECFA detector R&D roadmap - be addressed collaboratively.