Particle-induced desorption mass spectrometry of large involatile biomolecules: surface chemistry in the high-energy short-time domain

1982 ◽  
Vol 15 (9) ◽  
pp. 268-275 ◽  
Author(s):  
Ronald D. Macfarlane
Keyword(s):  
Mass Spectrometry ◽  
Surface Chemistry ◽  
Time Domain ◽  
High Energy ◽  
Desorption Mass Spectrometry ◽  
Short Time

Direct Characterization of Rubber-Surface Chemistry Using Laser Desorption Mass Spectrometry

1992 ◽  
Vol 65 (2) ◽  
pp. 411-426
Author(s):  
Walter H. Waddell ◽  
Kimberly A. Benzing ◽  
Larry R. Evans ◽  
John M. McMahon
Keyword(s):  
Mass Spectrometry ◽  
Surface Chemistry ◽  
Glass Plate ◽  
Laser Desorption ◽  
Molecular Ions ◽  
High Mass ◽  
Reaction Products ◽  
Laser Desorption Mass Spectrometry ◽  
Desorption Mass Spectrometry ◽  
Rubber Surface

Abstract Laser desorption mass spectrometry (LDMS) was used to directly characterize the surfaces of vulcanized natural-rubber compounds with or without an antiozonant (AOz) and an antioxidant mixture. Molecular ions of five intact molecules were observed on the rubber surface using a single laser pulse. The molecular ions represent the AOz, the three components comprising the antioxidant mixture, and a production impurity in the AOz. The surface chemistry of the AOz, N-(1,3-dimethylbutyl)-.N′-phenyl-para-phenylenediamine (HPPD), was explored in order to investigate the mechanism of rubber-surface aging and protection. Two sets of samples were prepared: ozone-aged HPPD films that had been deposited on a glass plate and ozone-aged cured rubber strips containing HPPD. Rubber samples were continually stretched to 25% elongation and relaxed during exposure to ozone. The mechanisms of ozone reaction with HPPD on glass and on stretched rubber are similar, since many reaction products were identical based on the presence of the same LDMS peaks; however, the reaction on rubber was considerably more complicated, since numerous additional high-mass peaks were observed. Based on the present LDMS data and in agreement with the conclusions of Lattimer, Rhee and coworkers, the mechanism of antiozonant protection of rubber is consistent with both scavenger and protective barrier models being operative. Sections from a truck tire that displayed premature sidewall cracking and a passenger tire that displayed sidewall discoloration were analyzed using LDMS. The specific modes of sidewall failure were determined.

scholarly journals A quasi-monoenergetic short time duration compact proton source for probing high energy density states of matter

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
J. I. Apiñaniz ◽  
S. Malko ◽  
R. Fedosejevs ◽  
W. Cayzac ◽  
X. Vaisseau ◽  
...  
Keyword(s):  
Energy Density ◽  
Proton Beam ◽  
Dense Matter ◽  
High Energy ◽  
High Repetition Rate ◽  
High Energy Density ◽  
Time Duration ◽  
Ultrashort Pulse Laser ◽  
Proton Source ◽  
Short Time

AbstractWe report on the development of a highly directional, narrow energy band, short time duration proton beam operating at high repetition rate. The protons are generated with an ultrashort-pulse laser interacting with a solid target and converted to a pencil-like narrow-band beam using a compact magnet-based energy selector. We experimentally demonstrate the production of a proton beam with an energy of 500 keV and energy spread well below 10$$\% $$ % , and a pulse duration of 260 ps. The energy loss of this beam is measured in a 2 $$\upmu $$ μ m thick solid Mylar target and found to be in good agreement with the theoretical predictions. The short time duration of the proton pulse makes it particularly well suited for applications involving the probing of highly transient plasma states produced in laser-matter interaction experiments. This proton source is particularly relevant for measurements of the proton stopping power in high energy density plasmas and warm dense matter.

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