Ammonia laser experiments

The results for the A state show that a different mechanism is operative. A series of femtosecond pump-probe experiments were performed at wavelengths corresponding to the Rydberg states A (v = 0,1,2) of ammonia molecules.64-66,68,69 The wavelengths used to access these vibrational levels were 214 nm, 211 nm, and 208 nm for the pump laser and 321 nm, 316.5 nm, and 312 nm for the probe laser, respectively. 

Figure8. (a) Pump-probe spectra of (NH3)2NH+ through the A (v= 0,1,2 corresponding to 214, 211, 208 nm, respectively) states the data reveal the influence of the vibrational level probed in the experiments, (b) Pump-probe spectrum of (NH3hH+ and (NH3)sH+ with pump pulses at 208 nm and probe pulses at 312 nm A (v = 2) of the ammonia molecule. The role of cluster size is evident. The delay time is the interval between the pump and probe laser, (a) Taken with permission from ref. 65 (b) Taken with permission from ref. 68.

With respect to the considerations above, research is split into three parts. The first is connected to the kinetic description of the release of ammonia from the biomass as function of temperature. This research employs infrared spectroscopy using a tunable diode laser. Here very small biomass particles are used that are heated up very rapidly in a small reactor, which ensures that transport effects are virtually excluded from the kinetic release effects. Since ammonia is released in very small quantities it is quite hard to detect. Therefore, we first measure CO release, which is easier. In the second part we investigate the propagation of a conversion front in biomass layers. Here we perform experiments and try to establish a modeling approach for the propagation by analytical and numerical approaches. In the third part the gas-phase conversion processes are described in terms of... 

High-resolution spectroscopic experiments provide a detailed experimental information on the shape of the intermolecular potential in the attractive regions. Recent improvements in supersonic beams and new laser techniques increased dramatically the sensitivity and resolution in the near-infrared region and opened to high-precision measurements the difficult far-infrared region. The latter development made it possible to investigate directly intermolecular vibration bands which are very sensitive probes of the shape of intermolecular potentials. The new spectroscopic techniques provide a lot of accurate data on interaction potentials for atom-molecule complexes, as well as on more complicated systems such as the HF, ammonia or water dimers. 

The considered experimented set - up can be applied in two different ways. The first one is to use is as a semiconductor sensor cooler with low heat dissipation to cool the sensor down to the ambient temperature. It is interesting to be applied in cryogenic range of temperatures. The second option is related with the cooler for high energy dissipation devices (for example laser diode cooler). The first set of experiments was performed with sorption heat pipe and ammonia as a working fluid to demonstrate the basic possibility to decrease the temperature of the heat loaded wall to compare with the temperature of this wall in the phase of loop heat pipe cooling mode. 

In a series of XeCl excimer laser photofragmentation and reaction tests with O2 and ammonia reactants, we were able to prove that all these clusters were, in fact, (Lax C,) lanthanum fuUerenes. As levitated positive ions in the FT-ICR apparatus, they are chemically inert, and they fragment only by successive C2 loss. Laser shrink wrapping experiments showed that the smallest cage that can surround two lanthanum atoms is and the minimum cage that can fit around three is Cgg. 

The observations of Ronn and Lide were confirmed in a similar experiment by Lemaire and co-workers, also carried out on CHyBr. Fourrier et studied the influence of CO2 laser light on ground state microwave transitions in ammonia. Here, however, some doubt remained as to whether the infrared pumping did not cause a purely thermal effect, i.e., heating. Ammonia was also investigated by Shimizu and where an N2O... 

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