Digital feedback loops for d.c. SQUIDs

✍ Scribed by D. Drung

• Book ID: 103051209
• Publisher: Elsevier Science
• Year: 1986
• Tongue: English
• Weight: 475 KB
• Volume: 26
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/0011-2275(86)90078-0

✦ Synopsis

Digital feedback loops for d.c. SQUIDs using pulse-rate modulation are proposed and investigated by simulations and measurements. The design of a d.c. SQUID magnetometer yields a simulated energy resolution of ~-11 h (h = Planck's constant) where ~ 3 h corresponds to additional noise due to the feedback loop. Measurements at Josephson sampler prototype chips showed that the digital feedback loop is very stable and fast enough to obtain a flicker-free display on an oscilloscope. In contrast to conventional feedback loops an integration of sensor and feedback loop on one or several chips with Josephson junctions seems feasible.