Large format, high dynamic range UV detector using MCPs and Timepix4 readouts

Large area microchannel plate (MCP) detectors have been identified as the leading candidates for upcoming NASA UV missions such as LUVOIR and HabEx. MCP detectors combine noiseless photon counting with good UV quantum efficiency, high spatial resolution, low intrinsic background and resistance to radiation damage. The large size of the instruments proposed for the focal planes (e.g. the Large Ultraviolet Multi-Object Spectrometer, LUMOS) require very large format detectors that must accommodate a very high dynamic range to handle the spectra from distant galaxies to nearby FUV bright B stars. Recently, MCPs have been fabricated in very large formats (200 x 200 mm). Much of the excellent imaging performance of these detectors is made possible by various types of readout anodes, which either utilize charge division or charge propagation time to encode the position of each event (e.g. Cross Strip [XS], Cross Delay Line [XDL] readouts) and associated electronics that determine the position of the incident UV photon. Over the past decade, our group at the Space Sciences Laboratory at Berkeley has been developing a new type of MCP readout based on the family of read out integrated circuits (ROICs) developed at CERN called Medipix/Timepix. The pixelated (256x256) Timepix ROIC can sample the MCP charge clouds to determine event centroids. Because the sampling pixels are small (55 micron), the amplifier noise is very low (<75e- rms) allowing a very low MCP gain (~50,000) to achieve spatial resolutions on the order of the MCP pore spacing. Since all the pixels are independent, this resolution is independent of the number of readout ROICs used to support larger MCPs. Unfortunately, the original Timepix and its successor, the Timepix3, could only be abutted on 3 sides, the fourth side used for I/O wirebonds. Therefore only 2xN arrays of these 17 x 14mm chips could be used, limiting the area of such an MCP detector, so it was never proposed for use in the large format NASA applications mentioned above. However, the Timepix readout has been used in many of our detectors in the field, specifically 2x2 arrays for a 28x28mm readout for neutron detection in many neutron beamlines around the world. The latest generation of this family of ROICs is the Timepix4 (Tpx4), which has many new features that make it an excellent candidate for large format MCP detectors. The Tpx4 is four times larger in area (28 x 25 mm), still with 55 microns pixels (512x448 array). It is also abuttable on 4 sides, allowing unlimited tiling of a mosaic. This was enabled by “through chip via” technology, negating the need for wirebonds, as all signals and power can come from the rear side of the chip. The Tpx4 has an event driven readout, with the capability of 250MHz event rate per chip, well beyond the high rate requirements of any proposed NASA mission. Finally, the Tpx4 can be operated in an ultra-low power mode such that a future array of 7 x 8 (196 x 196 mm) Tpx4 chips could be operated for less than 28 Watts. The Tpx4 design by the CERN Microelectronics Group is currently in its final stage and is expected to be submitted for fabrication in late spring with the first dies to be tested by the end of 2019. As a founding member of the Timepix4/Medipix4 collaboration, our group has access to the chips along with the expertise of CERN and other collaborators in this joint ROIC development. Our goal is to design and fabricate a 100 x 100 mm MCP detector with a 3x3 array of Tpx4 ROICS, demonstrating its imaging performance in a four-side abutted array of ROICs. This device will be environmentally tested in our thermal/vacuum chambers at SSL as well as our vibration facility. We also plan to test its radiation tolerance, which is expected to be better than the excellent resistance of its precursors. This effort will result in a TRL5 detector that can be scaled to the ultimate design of the 200mm detectors needed for NASA's next generation of UV telescopes.

The Strategic Astrophysics Technology program (SAT) supports focused development efforts for key technologies to the point at which they are ready to feed into major missions in the three science themes of the Astrophysics Division: Exoplanet Exploration, Cosmic Origins, and the Physics of the Cosmos. This program is specifically designed to address middle technology readiness level (TRL) "gaps" between levels 3 and 6: the maturation of technologies that have been established as feasible, but which are not yet sufficiently mature to incorporate into flight missions without introducing an unacceptable level of risk. NASA does not require a data management plan for proposals to SAT.

This is early/mid-stage (TRL 4) — the most realistic path in is NASA SBIR/STTR, which funds small businesses and research institutions to develop technology aligned with NASA's needs (equity-free, phased funding). Check whether a current SBIR/STTR solicitation topic overlaps with this project's technology area, or contact the project directly (above) to ask.

None of these are guaranteed paths for this specific project — TechPort itself doesn't have an "apply" button. Reaching out to the contact(s) above with a specific question is usually the fastest way to find out what's actually open.