The composition of narrow distribution poly ethylene oxide-propylene oxide copolymer (Mw ~ 8700 Da) was studied using matrix assisted laser desorption ionization (MALDI) mass spectrometry. The ethylene oxide-propylene oxide copolymer produced oligomers separated by 14 Da. The average resolving power over the entire spectrum was 28,000. Approximately 448 isotopically resolved peaks representing ...

Recent advances in soft ionization techniques for mass spectrometry of polymeric materials make it possible to determine the mass of intact molecular ions exceeding 1 x 1 OS Da. Developments in high resolution mass spectrometers have additionally led to impressive advances in our ability to characterize polymers. The entire molecular mass distribution of a polymer sample can be accurately measu...

Measurements of the neutron spectrum from the T(t,2n)4He (tt) reaction have been conducted using inertial confinement fusion implosions at the OMEGA laser facility. In these experiments, deuterium-tritium (DT) gas-filled capsules were imploded to study the tt reaction in thermonuclear plasmas at low reactant center-of-mass (c.m.) energies. In contrast to accelerator experiments at higher c.m. e...

α-Cyano-4-hydroxycinnamic acid (CHCA), an organic matrix molecule for matrix-assisted laser desorption/ionization mass spectrometry, was adsorbed to NH4 (+)-type zeolite surface, and this new matrix was used for the detection of low-molecular-weight compounds. It was found that this matrix could simplify the mass spectrum in the low-molecular-weight region and prevent interference from fragment...

In this report, we describe a simple and accurate method to analyze restriction fragments using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The two complementary strands of restriction fragments are separated through hybridization to a capture probe, which is a single-stranded undigested fragment. Using the biotin-streptavidin linkage, the hybrid is immobilized...

We study interference effects between resonant and nonresonant amplitudes for the γγ → W + W − process at a backscattered photon-photon collider. We show that a Higgs boson with M H > ∼ 200 GeV is manifest as a resonant dip in the W + W − invariant mass spectrum and we investigate its statistical significance. There has been recent interest in weak gauge boson pair production in γγ collisions a...

A statistical method is reported to determine the pairs of fragment ions in a mass spectrum that are most susceptible to control by adaptive optimization of the laser pulse shapes in the strong-field regime. The proposed method is based on covariance analysis of the mass spectral fragmentation patterns generated by a set of randomly shaped pulses. The pairs of fragment ions that have higher neg...

The cooling of molecules during the adiabatic expansion of supersonic seeded molecular beams is reviewed and illustrated by the example of NO -molecules. The reduction of the Doppler width by collimation of the beam and the cooling to low rotational temperatures brings a significant simplification of the complex NO -absorption spectrum and allows its assignment. The measured rotational tem...

The photoionization and fragmentation of octadecane were investigated with infrared laser desorption/tunable synchrotron vacuum ultraviolet (VUV) photoionization mass spectrometry (IRLD/VUV PIMS) and theoretical calculations. Mass spectra of octadecane were measured at various photon energies. The fragment ions were gradually detected with the increase of photon energy. The main fragment ions w...

Matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry is a technique for high mass-resolution analysis of substances that is rapidly gaining popularity as an analytic tool. Extracting signal from the background noise, however, poses significant challenges. In this article, we model the noise part of a spectrum as an autoregressive, moving averag...