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Tijmen de Haan
QUP Senior Scientist
Assistant Professor
KEK IPNS
e-mail tijmen-at-post.kek.jp
Tijmen de Haan is a Dutch-Canadian experimental astrophysicist and cosmologist. His primary interest is in the Cosmic Microwave Background (CMB), using the tools of physics, statistics, and electrical engineering to make increasingly precise measurements of the remnant radiation of the Big Bang. On the weekend, Tijmen likes to play piano and cook elaborate meals.
Research Content
A member of several CMB experiments, including the South Pole Telescope, Simons Array, Simons Observatory, CMB-S4, Tijmen's primary focus is currently on the upcoming CMB satellite experiment LiteBIRD. Launching in the late 2020s, LiteBIRD will measure the large-scale polarization of the CMB to unprecedented precision. An increase of two orders of magnitude over the previous CMB satellite (Planck) requires new technologies. One of these is the frequency-domain multiplexed readout of large arrays of monolithically fabricated Transition Edge Sensor (TES) bolometers. We are in the process of adapting this technology for use in space. Novel developments include the use of lossless voltage bias generation, the use of SQUID Series Array Amplifiers at sub-Kelvin temperatures, and the full physics-based modeling and timestream analysis of TES bolometers.
Related Research Results
Selected publications:
"Probing Cosmic Inflation with the LiteBIRD Cosmic Microwave Background Polarization Survey", LiteBIRD Collaboration (2022)
"Recent Advances in Frequency-Multiplexed TES Readout: Vastly Reduced Parasitics and an Increase in Multiplexing Factor with Sub-Kelvin SQUIDs", T. de Haan et al. (2020)
"Cosmological Constraints from Galaxy Clusters in the 2500 square-degree SPT-SZ Survey", T. de Haan et al. (2017)
"Improved performance of TES bolometers using digital feedback" T. de Haan et al. (2012)
