The process for technological decision in NEXT finished with the preparation of proposals for CDR (CDRP). The CDRP dubbed MAGIC, based on Micromegas readouts gathers much of the work done under T-REX by our group to study Micromegas readouts for double beta decay.
You can find the full document here: preCDR_MAGIC_v10
The main elements of the proposal is:
1) Charge readout of a mosaic of Micromegas microbulk readouts. Energy and topology are extracted from this reading
2) Prompt scintillation reading for t0 purposes with a sparse PMT set.
3) Extremely radiopure design. Copper vessel, field cage of kapton and copper.
4) Signals extraction based on radiopure flat kapton cables, as well as high density feedthroughs already developed in the group’s prototype
5) Preliminary background model developed. Competitive sensitivity prospects anticipated
6) The merits of this proposal relies on its cost-effectiveness, its relative simplicity, the conservative use of materials regarding their radiopurity, the optimized balance between energy resolution and background towards the figure of merit of the experiment and the possibility of implementing future improvements.
Note added 15-May-2011: The NEXT Collaboration did not chose this CDRP but a detector concept base on the electroluminescence signal.