As one of the backend modules aboard the China Space Station Telescope, the high-sensitivity terahertz detection module (HSTDM) needs to be rationally scheduled to conduct various observation tasks to fulfill and maximize its scientific goals. This is because HSTDM cannot operate simultaneously with other modules, and the observable time windows determined by constrained and changeable conditions are randomly distributed and limited; even worse, the total allocated time is estimated to account for less than 10% of the total in-orbit time. We develop a modified genetic algorithm (MGA) to better solve this problem. Compared with conventional genetics algorithm (CGA), the core uniqueness of this method are as follows: (1) reduce the search space of chromosomes by pre-calculating the observable time windows of observing objects; (2) accelerate the exploration and exploitation of chromosomes by a transformation process that reduces the chromosome length through recombination of non-zero valued genes, followed by increasing the initial population diversity through the proposed similarity avoidance based population generation method and then by adopting stochastic universal sampling and elitism selection combined parents selection method; and (3) design a compound fitness function that can simultaneously achieve three optimization criteria through evolution process. The effectiveness of the proposed method is validated on a simulated scenario, and performance comparisons with CGA suggest that MGA can generate more profitable solutions (as much as 46% improvement) in fewer (as much as 90% reduction) generations.
Superconducting transition-edge sensors (TESs) are highly sensitive detectors and can detect electromagnetic wave radiations from millimeter/submillimeter, optical to 𝑥/γrays, suitable for cosmology, astrophysics, quantum information, and biosensing. In principle, thousands of TESs even more are required to enhance the detection efficiency for large-scale survey. Among other multiplexing schemes, microwave SQUID multiplexer (μMUX), consisting of resonators and RF SQUIDs, has a bandwidth of several GHz, thus multiplexing factor on the order of thousands, more suitable for readout of large TES arrays. We designed and fabricated superconducting coplanar waveguide (CPW) resonators with a high qualityfactor and second-order gradient RF SQUID with two inductive coupling structures respectively. Then, we optimized the critical current density of the Josephson junction and measured the mutual inductance parameters of the second-order gradient structure SQUID, which are consistent with the simulation results. Finally, we fabricated a cryogenic μMUX chip based on RF SQUID and resonator. We discussed the results of the development of μMUX in more detail.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.