In Memoriam: Bill Sippach, 1929-2023

F. William (“Bill”) Sippach started work as an electronics engineer at Nevis Laboratories, Columbia University on March 1, 1962. He was hired by Walter LeCroy, and soon thereafter took over as the head of the Nevis electronics shop when Walter left Columbia to form his own company. Over an extraordinary career that spanned six decades, Bill played crucial roles in the successes of many generations of particle, nuclear, and astrophysicist experiments, including at many of the major international labs, such as CERN, Fermilab, DESY, and BNL. His physics background provided Bill with a deep understanding of the needs of the various experiments, and he worked closely with the Nevis physicists to ensure the performance of the innovative electronics system he developed matched those requirements.

Bill Sippach at Nevis
Bill Sippach at work in his office at Nevis Labs, Columbia University.

Over 60 years, from the time of the introduction of the very first commercial integrated circuits until the present day, Bill continuously learned and adapted, and kept himself at the cutting edge of the very rapidly advancing electronics technology. While starting his career in the age of vacuum tubes, he continuously evolved, and even became an expert at full-custom ASIC design. He was a pioneer in the development of data-driven readout systems that are now the norm. He designed the ZEUS uranium-scintillator calorimeter readout, including both the on-detector analog electronics and the off-detector digital processing electronics. This fully pipelined system, which started data taking in 1992, handled a 96 ns bunch crossing time and 1 kHz Level 1 trigger rate with minimal deadtime. Bill’s ZEUS calorimeter readout design was ahead of its time, providing a solid basis for his design of the ATLAS liquid argon (LAr) calorimeter readout at the LHC, almost 20 years later. The ATLAS design had to handle a 25 ns bunch crossing time and a 100 kHz Level 1 trigger rate, all with improved analog precision, and required the development of 11 different custom ASICs, 5 of which were designed at Nevis under Bill’s leadership. Variants of the design were adapted as the basis for key readout systems of the PHENIX detector at RHIC. Bill was also highly skilled with the development of digital processing systems using state-of-the-art FPGAs and processors, for example developing the Level 1 calorimeter trigger for an upgrade of the DZero experiment, and also the readout electronics of the MicroBoone experiment.

On the neutrino side going beyond the early neutrino experiments of Lederman, Schwartz, and Steinberger, Bill developed new readout and data acquisition systems associated with the neutrino experiments: E744/E770 (Fermilab), NuTeV (Fermilab), E776 (BNL) and Double Chooz (France). This was followed by his development of novel readout systems for the new Liquid Argon Time-Projection detector technology associated with the MicroBooNE and SBND experiments at Fermilab. For these experiments, he was able to produce dual-stream electronics that allow the experiments to collect both neutrino beam data events as well as continuous stream readout events that open up supernova and nucleon decay physics capabilities. His innovations are now being taken over as inputs for designing electronics for the new flagship DUNE neutrino experiment.

While Bill formally retired in 2018, he continued to contribute. His most recent accomplishments including developing the readout for a number of detector systems of the sPHENIX detector at BNL, that will start taking data later this year, and contributing significantly to the design of the ATLAS LAr frontend readout under development for the HL-LHC phase at CERN. It finally took the COVID19 pandemic to prevent him from coming in to his Nevis Labs office.

Bill was talented at everything from ASIC design, through board design, and even system design. His innovative designs made possible discoveries that were rewarded with Nobel prizes, and he was recognized world-wide as one of the very best electrical engineers working in particle physics.

Working with Bill was always a great pleasure, for the lessons one could learn from his incredible expertise and experience, and also for his modest manner and incredible dry wit. His legacy lives on, but he will be sorely missed. Our thoughts are with his family at this difficult time.

Sippach Fest 2018
Participants at “Sippach Fest”, held at Nevis Labs, Columbia University in November 2018, on the occasion of Bill’s formal retirement, to celebrate and commemorate Bill’s extraordinary career spanning six decades.