William A. Barletta

Research Interests

William Barletta maintains a broad range of professional research activities that include free electron laser physics for ultra-fast synchrotron radiation science, the design of colliders and high intensity linacs and cyclotrons for high energy and nuclear physics, ion beam technology for nanofabrication of integrated circuits, and compact plasma-based neutron and gamma sources for medicine, research and security applications. In addition he has an active research interests in coronavirus epidemiology, in strategic management of research institutions, and in international legal and policy aspects of cyber-conflict.

Free electron lasers (FEL): Work in the early ‘80s concerning analytical and computational studies of generating bright, high current beams of ions (for inertial fusion) and electrons (for driving FELs) was the first exploration of the influence of non-linear space charge forces within beams to drive emittance growth both during beam transport. The plasma transport work with Sessler was the first exploration of using weak ion channels within undulators to increase FEL gain and also led to the first published proposal (1988) to use synchrotron radiation during plasma transport (now called betatron radiation) to make a powerful source of gamma rays. His analysis of the FEL as a buncher of space-charge dominated beams led to an SBIR grant to design and build a high current source with sub-nanosecond rise time and 100 Hz rate, used for several years as monopole electromagnetic radiation source. He was the original proponent of a high-gain, high-harmonic generator cascade in a master oscillator-power-amplifier configuration to generate fully phase coherent soft X-ray beams for the FERMI@elettra project at Sincrotrone Trieste. He oversaw the Berkeley design effort of this FEL and has continued to serve as an advisor to the President of Sincrotrone Trieste regarding upgrades of the facility.

High energy colliders: During the design phase of the PEP-II B-factor, he was chief vacuum technologist. He produced the design concepts for the vacuum systems of both rings of the collider that handed unprecedented levels of synchrotron radiation. The choice of materials for the vacuum chambers were based on his measurements with Forester of the engineering properties of copper, aluminum, steel alloys exposed to extremely high cumulative X-ray doses. He also developed an approach to maintain extremely high vacuum conditions near the interaction points. Actual construction began after he left the project to lead the LBNL accelerator division. His active interest in energy frontier proton colliders has included overall system studies, work with the LBNL magnet program to drive the design of very high field accelerator magnets, and analysis of issues concerning synchrotron radiation in cryogenic environments. His paper in 1993 was the first to propose the use of thin-film high temperature superconductors as a coating for the proton collider vacuum channel – an idea now being considered by CERN.

Ion beam technology: Working with the group of Leung at LBNL, he invented the x-y addressable low voltage pattern generator plus a multi-cusp (magnetic field) ion source to replace stencil masks for ion-beam reduction lithography. This patented work led to several experimental investigations to refine the concept by shaping the exist holes of the pattern generator and shielding external fields. This concept also permitted detecting a single ion passing through a channel of the pattern generator. Thus, this device can be used to implant single ions on a Si substrate at 25 nm spacing. The multi-cusp source was also the basis for other patented devices to generate compact sources of neutrons (for security and medical use) and gamma rays (for security applications).

His work at MIT has concentrated on the design and use of high current cyclotrons for both discovery science and industrial applications and on fourth generation synchrotron light sources. His newest research area has been in the epidemiology of coronavirus infections.

Biographic Sketch

William Barletta received his Ph.D. in experimental high-energy physics from the University of Chicago in 1972. After a term as instructor of physics at Yale University, he joined Lawrence Livermore National Laboratory where he held several research and management positions. From 1993 – 2006, he was Director of the Accelerator Division and of the Homeland Security and Non-proliferation Program at the Lawrence Berkeley National Laboratory. At Berkeley he was responsible for LBNL’s activities in four major construction projects of major research infrastructures: the PEP-II B-factory (low energy ring), the US-LHC project (interaction region components), the Spallation Neutron Source (delivered the front-end systems), and the LANL DARHT radiography project (delivered the accelerator cells).

As Chairman of the USPAS Board (1999 – 2005) and USPAS Director (2006 – 2017), he was responsible for a national graduate program covering all aspects of accelerator science and technology that are crucial to research infrastructures for accelerator-based science. He built the academic presence of accelerator physics by creating mechanisms for students from MIT, Old Dominion, Stony Brook, and Michigan State universities to receive direct home university credit for USPAS courses. With his MIT colleagues, he has established a regular course in accelerator science in the physics department and a flexible major in accelerator physics. He is also the inaugural director of the Korean Accelerator School.

Service to the Profession: As the coordinating editor-in-chief of the international journal, “Nuclear Instruments and Methods in Physics Research – A” and Editor-in-Chief of “Physics Open”, he coordinates editorial policy and decisions and personally handles ~400 manuscripts annually. He is the Councilor for the American Physical Society (APS) Forum on International Physics and the Secretary-Treasurer Elect of the APS Division of Physics of Beams. He has been an active member of the APS Panel on Public Affairs, Committee on Minorities (2004-2006), the APS Committee on International Scientific Affairs (2011 – 2013), and the American Bar Association Privacy & Computer Crime Committee.

Barletta has been an organizer of more than 30 international conferences and schools in accelerator science, in coherent interactions of radiation and matter, and in innovative technologies to clean the environment. He has written a textbook “Strategic Management of Research Organizations,” edited and co-authored four books about accelerator science, and co-authored four books concerning cybersecurity, privacy and international cyber-law, including “Averting Disaster: Science for Peace in a Perilous Age,” “The Quest for Cyber Peace,” and the “Quest for Cyber Confidence”, the latter two published by the International Telecommunications Union of the United Nations. He holds four patents with three patents pending, and is author of more than190 papers plus 30 internal reports on strategic technologies. He is a fellow of the American Physical Society and the Academy of Sciences of the Bologna Institute (Italy).