Interview with Thomas A. Tombrello on LIGO

Interview, December 2, 1998, with Thomas A. Tombrello, then chairman of the Division of Physics, Mathematics, and Astronomy. Recalls arriving at Caltech in 1961 as postdoc with Tommy Lauritsen. Early work at Caltech on gravitational-wave detectors. Role of Kip S. Thorne, James Mercereau. 1976 committee to pursue gravitational-wave work. Arrival of Ronald W. P. Drever. MIT involvement under Rainer Weiss. Hiring of Frederick Raab and Jeff Kimble. Tombrello proposes Rochus (Robbie) Vogt as LIGO head, 1987; his relationship with Vogt. Vogt's dismissal as provost 1987 and lobbying effort for LIGO in Washington. Problems with Drever. LIGO's growing pains, late 1980s, early 1990s. President Thomas Everhart's lack of involvement. Vogt's difficulties leading an expanding LIGO. Formation of LIGO Oversight Committee under Lew Allen. National Science Foundation's involvement. NSF meeting January 1994 and dismissal of Vogt as director. Barry Barish becomes director. Earlier mishandling of Drever affair by Academic Freedom and Tenure Committee. Discussion of bad feelings on campus and within project. Current promising outlook under Barish. How LIGO project is viewed at Caltech and at MIT. Raab's tenure problems. Tombrello as tenure committee head; role of Kenneth Libbrecht. Raab as Hanford site manager. LIGO's prospects. Fallout from dismissal of Vogt and Drever in early 1990s. Comments on new Caltech president David Baltimore, and on former presidents Marvin L. Goldberger and Harold Brown and former geology division chairman Robert Sharp. Comments on reengineering project begun under Everhart

Radiation-induced interface phenomena: Decoration of high-energy density ion tracks

The effect of 20 MeV Cl4 + ions incident on Au-SiO2 and Ag-SiO2 interfaces was investigated using high-resolution transmission electron microscopy. Cross-sectional micrographs expose beam-induced gold interfacial transport and migration into the SiO2. No such migration was observed for silver films. The relevance of this phenomenon to the adhesion improvement found at corresponding irradiation doses is discussed

Enhanced adhesion of films to semiconductors or metals by high energy bombardment

Films (12) of a metal such as gold or other non-insulator materials are firmly bonded to other non-insulators such as semiconductor substrates (10), suitably silicon or gallium arsenide by irradiating the interface with high energy ions. The process results in improved adhesion without excessive doping and provides a low resistance contact to the semiconductor. Thick layers can be bonded by depositing or doping the interfacial surfaces with fissionable elements or alpha emitters. The process can be utilized to apply very small, low resistance electrodes (78) to light-emitting solid state laser diodes (60) to form a laser device 70

Interview with Thomas A. Tombrello

Interview in nine sessions (December 26–December 31, 2010) with Thomas A. Tombrello, the Robert H. Goddard Professor of Physics, Caltech. Each session is organized around a central topic or theme: (1) early years through college, (2) fifty-year career overview, (3) undergraduate students, (4) Kellogg Radiation Laboratory years, (5) work with Schlumberger research laboratory, (6) Caltech people and personalities, (7) work with national weapons laboratories, (8) ten-year tenure (1998–2008) as chair of Caltech’s Division of Physics, Mathematics and Astronomy, and (9) graduate students and miscellaneous topics. Tombrello opens with his family history, youth, early life, and education, primarily in Texas and Alabama, and his undergraduate (BA 1958) and graduate (PhD 1961) years at Rice Institute. He talks at length about his years in Caltech’s Kellogg Radiation Laboratory, including his research into nuclear physics, materials science, and applied physics, and about the science, culture, people, personalities, politics, and economics of Kellogg and the Division of Physics, Mathematics and Astronomy (PMA) over fifty years. There is extensive discussion of his mentoring work with Caltech undergraduate and graduate students, including his innovative undergraduate course Physics 11 and his perspectives on student life at Caltech. Of particular note is the discussion of his relationship with S. E. Koonin, who went from being Tombrello’s undergraduate advisee to his provost. Tombrello provides a wide-ranging, in-depth look at his ten years as division chair of PMA, covering research, recruitment, fundraising, collegial relationships within and beyond the division and with JPL, and the evolution of PMA under his oversight. He talks about his involvement in the design and construction of the Cahill Center for Astrophysics (dedicated in 2009) and the Thirty Meter Telescope (TMT) project. He describes his interactions with five decades of Caltech presidents and provosts, institute trustees, and various donors. Tombrello recaps his two years as research director at Schlumberger research and his several decades of consulting work on weapons, national security, energy, and climate change issues at Los Alamos and Lawrence Livermore National Laboratories. He talks about his foray into earthquake prediction research, his research collaborations in China, his years as Caltech’s technology assessment officer, and the emergence of entrepreneurism at Caltech in the 1990s. Anecdotes and recollections of such notable Caltech figures as R. Bacher, J. Benton, H. Brown, L. DuBridge, R. Feynman, W. A. Fowler, M. Gell-Mann, B. Kamb A. Lange, C. Lauritsen, T. Lauritsen, R. Leighton, C. Patterson, R. Sharp, and F. Zwicky are also part of this oral histor

Enhanced adhesion by high energy bombardment

Films (12) of gold, copper, silicon nitride, or other materials are firmly bonded to insulator substrates (12) such as silica, a ferrite, or Teflon (polytetrafluorethylene) by irradiating the interface with high energy ions. Apparently, track forming processes in the electronic stopping region cause intermixing in a thin surface layer resulting in improved adhesion without excessive doping. Thick layers can be bonded by depositing or doping the interfacial surfaces with fissionable elements or alpha emitters

Significant Expansion of Real-Time PCR Multiplexing with Traditional Chemistries using Amplitude Modulation

The real time polymerase chain reaction (rtPCR) is an essential method for detecting nucleic acids that has a wide range of clinical and research applications. Current multiplexed rtPCR is capable of detecting four to six nucleic acid targets in a single sample. However, advances in clinical medicine are driving the need to measure many more targets at once. We demonstrate a novel method which significantly increases the multiplexing capability of any existing rtPCR instrument without new hardware, software, or chemistry. The technique works by varying the relative TaqMan probe concentrations amongst targets that are measured in a single fluorometric channel. Our fluorescent amplitude modulation method generates a unique rtPCR signature for every combination of targets present in a reaction. We demonstrate this technique by measuring nine different targets across three color channels with TaqMan reporting probes, yielding a detection accuracy of 98.9% across all combinations of targets. In principle this method could be extended to measure 6 or more targets per color channel across any number of color channels without loss in specificity

Significant Expansion of Real-Time PCR Multiplexing with Traditional Chemistries using Amplitude Modulation

The real time polymerase chain reaction (rtPCR) is an essential method for detecting nucleic acids that has a wide range of clinical and research applications. Current multiplexed rtPCR is capable of detecting four to six nucleic acid targets in a single sample. However, advances in clinical medicine are driving the need to measure many more targets at once. We demonstrate a novel method which significantly increases the multiplexing capability of any existing rtPCR instrument without new hardware, software, or chemistry. The technique works by varying the relative TaqMan probe concentrations amongst targets that are measured in a single fluorometric channel. Our fluorescent amplitude modulation method generates a unique rtPCR signature for every combination of targets present in a reaction. We demonstrate this technique by measuring nine different targets across three color channels with TaqMan reporting probes, yielding a detection accuracy of 98.9% across all combinations of targets. In principle this method could be extended to measure 6 or more targets per color channel across any number of color channels without loss in specificity

Ab initio alpha-alpha scattering

Processes involving alpha particles and alpha-like nuclei comprise a major part of stellar nucleosynthesis and hypothesized mechanisms for thermonuclear supernovae. In an effort towards understanding alpha processes from first principles, we describe in this letter the first ab initio calculation of alpha-alpha scattering. We use lattice effective field theory to describe the low-energy interactions of nucleons and apply a technique called the adiabatic projection method to reduce the eight-body system to an effective two-cluster system. We find good agreement between lattice results and experimental phase shifts for S-wave and D-wave scattering. The computational scaling with particle number suggests that alpha processes involving heavier nuclei are also within reach in the near future.Comment: 6 pages, 6 figure

A cluster model of the light nuclei

This thesis is divided into two major parts. In the first, "A Cluster Model of the Light Nuclei," a nuclear model is developed which is based on the premise that the light nuclei may be described in terms of two-body clusters of nucleons. A simple mathematical formulation of the model is given and numerical calculations are used to exhibit the properties of this model. In many instances the model's predictions are compared to the experimental data, and possible extensions of the model's usefulness are cited. In the second part, "The Study of Nuclear Properties by Means of Radiative Capture Reactions," the two-body nature of the cluster model is exploited in the calculation of radiative capture transition probabilities. Most of this part is devoted to the analysis of these reactions for the study of nuclear structure; however, some new experimental results are given for the D(p,gamma)He3 and D(alpha,gamma)Li6 reactions