Ultrafast optical probing is a widely used method of underdense plasma diagnostic. In relativistic plasma, the motion blur limits spatial resolution in the direction of motion. For many high-power lasers the initial pulse duration of 30–50 fs results in a 10–15 μm motion blur, which can be reduced by probe pulse post-compression. Here we used the compression after compressor approach [Phys.-Usp. 62, 1096 (2019); JINST 17 P07035 (2022)], where spectral broadening is performed in thin optical plates and is followed by reflections from negative-dispersion mirrors. Our initially low-intensity probe beam was down-collimated for a more efficient spectral broadening and higher probe-to-self-emission intensity ratio. The setup is compact, fits in a vacuum chamber and can be implemented within a short experimental time slot. We proved that the compressed pulse retained the high quality necessary for plasma probing.

An electromigration study has determined the lifetime characteristics and failure mode of dual-damascene Cu/oxide interconnects at temperatures ranging between 200 and 325 °C at a current density of 1.0 MA/cm2. A novel test structure design is used which incorporates a repeated chain of “Blech-type” line elements. The large interconnect ensemble permits a statistical approach to addressing interconnect reliability issues using typical failure analysis tools such as focused ion beam imaging. The larger sample size of the test structure thus enables efficient identification of “early failure” or extrinsic modes of interconnect failure associated with process development. The analysis so far indicates that two major damage modes are observable: (1) via-voiding and (2) voiding within the damascene trench.

A number of recent papers have shown that it is possible for an investor to immunize a portfolio of default and option-free coupon bonds so that the return realized over a given planning period will never be less than that promised at the time the bonds were purchased. In this way, a future fixed dollar liability may be discharged with certainty by acquiring an asset portfolio with a market value equal to the present value of the liability and setting its appropriate duration equal to the time remaining to the date of discharge. However, most investors have more than one liability to discharge. In his seminal article in 1952, F. M. Redington showed that a stream of liabilities may be immunized if an asset portfolio having the same present value as the liabilities is selected so that:

1. its duration is equal to the duration of the liabilities; and

2. “the spread of the value of asset-proceeds about the mean term (duration) should be greater than the spread of the value of the liability” ([16], p. 191).

In recent years, academicians and practitioners have been using the concept of duration more frequently in the analysis of debt securities. Although the use of duration has greatly expanded our insights into the behavior of bond prices and bond risk, it has given rise to a considerable degree of confusion and misunderstanding. The purpose of this review paper is twofold: (1) to clarify the record on what duration is and is not and what it can do and cannot do, and (2) to discuss the appropriate uses of duration in the analysis of security portfolios.

In recent years, a number of studies have been published evaluating alternative bond portfolio strategies. These studies basically simulate risk-return characteristics for a variety of strategies designed for use by financial institutions. Typical strategies considered include portfolios of bonds that have laddered or barbell (dumbbell) maturity structures. In laddered strategies, bonds are spaced evenly among a number of consecutive maturities, while in barbell strategies, bonds are concentrated in short and long maturities. The results of these studies tend to differ and conflict. For example, in a recent article in this journal, Fogler, Groves, and Richardson (FGR) conclude that “dumbbell portfolio strategies are not as efficient as indicated by previous analyses.” Among the previous studies to which they refer is one by Watson, who concluded that “portfolios split between a spaced group of short maturity bonds and a longer investment security” (barbell portfolios) are most efficient. Similar results are reported by Wolf and by Bradley and Crane.

The asset and liability portfolios of financial institutions generate patterns of future cash flows that must conform to many restrictions in order to assure solvency and profitability. Many institutions, including insurance companies and pension funds, have definite and certain future commitments of funds. These institutions may wish to invest funds now so that their cash inflows (investment with accumulated earnings) will match their future commitments. In principle, the simplest way to meet future commitments exactly is to purchase single payment notes (or zero coupon bonds) which mature on the commitment dates. For long-term commitments, such instruments are not readily obtainable, at least in the United States. Most available bonds promise coupon payments over time so that these payments would have to be reinvested at unknown future interest rates in order to realize an accumulated sum at any future date when a commitment must be discharged. Since future interest rates are unknown at the initial moment of investment, it is not certain what accumulated earnings will be at future dates. In the absence of default, the risk of not meeting future commitments may be minimized by adopting investment strategies based on the concept of duration. Duration is a measure of the average maturity of an income stream; it is a weighted average of the dates at which the income payments are received, where the weights add to unity and are related to the present value of the income stream. Dating from the initial work of Macaulay [9] and Hicks [6], duration has been shown to be important in constructing portfolios that are hedged or ‘immunized’ from the possible ravages of interest rate uncertainty.