C-0 gases

Ar, Cs, Ga or other elements with energies between 0.5 and 10 keV), energy is deposited in the surface region of the sample by a collisional cascade. Some of the energy will return to the surface and stimulate the ejection of atoms, ions and multi-atomic clusters (figure Bl.25.8). In SIMS, secondary ions (positive or negative) are detected directly with a mass spectrometer. 

Other miscellaneous applications of malononitdle are the synthesis of 7,7,8,8-tetracyanoquinodimethane (46) which is a powerful electron acceptor in the formation of charge-transfer complexes which are of interest because of their conductivity of electricity (96), as well as of 2-chloroben2yhdene malononitnle [2698-41-1] (45) also known as CS-gas, which is a safe lachrymatory chemical used for self-defense devices (97). 

The control of materials purity and of environmental conditions requires to implement physico-chemical analysis tools like ESC A, RBS, AUGER, SEM, XTM, SIMS or others. The principle of SIMS (Secondary Ion Mass Spectroscopy) is shown in Eig. 31 an ion gun projects common ions (like 0+, Ar+, Cs+, Ga+,. ..) onto the sample to analyze. In the same time a flood gun projects an electron beam on the sample to neutralize the clusters. The sample surface ejects electrons, which are detected with a scintillator, and secondary ions which are detected by mass spectrometry with a magnetic quadrupole. 

CS gas Propanedinitrile [(2-chlorophenyl) methylene] tear gas used for riot and crowd control. 

In SIMSLAB from VG Scientific, both surface analytical techniques - SIMS and SNMS - have been applied (see Figure 5.34). In this mass spectrometer different types of primary ion sources are available. Ar+, Cs+, Ga+ or O) primary ions are accelerated in the secondary ion source on the solid sample surface. Similar to the CAMECA IMS-7f, with this experimental arrangement, besides depth profiling, a microlocal analysis can also be performed. The sputtered secondary ions (for SIMS) or the post-ionized sputtered neutrals (for SNMS) - the post-ionization is carried out by an electron beam in an ionizer box (right-hand schematic in Figure 5.34) - are separated... 

Procedures for the determination of 11 elements in coal—Sb, As, Br, Cd, Cs, Ga, Hg, Rb, Se, U, and Zn—by neutron activation analysis with radiochemical separation are summarized. Separation techniques include direct combustion, distillation, precipitation, ion exchange, and solvent extraction. The evaluation of the radiochemical neutron activation analysis for the determination of mercury in coal used by the Bureau of Mines in its mercury round-robin program is discussed. Neutron activation analysis has played an important role in recent programs to evaluate and test analysis methods and to develop standards for trace elements in coal carried out by the National Bureau of Standards and the Environmental Protection Agency. 

Crown-6 , see 1,4,7,10,13,16-Hexaoxacyclooctadecane, 3555 Crown ethers , see Cyclic poly(ethylene oxides), 0826 CS gas , see 2-Chlorobenzylidenemalononitrile, 3232b Cubane-l,2-dicarboxylic acid, see Pentacyclo[4.2.0.02 5.03,8.04,7]octane-1,2-dicarboxylic acid, 3255... 

Fig. 21 Variation of the effective magnetic moment with temperature for 8.4% [Ti(OH2)5] cation doped into Cs[Ga(0H2)6](S04)2 6H2O. The curve labelled ligand field theory was calculated from the basis states of the Eg(Ss) term only with X = 130cm and k = 0.88. The curve labelled Jahn-TeUer fit was calculated with the same electronic parameters but allowing for Jahn-Teller coupling to two modes with energies of 53 and 894 cm [50]...

See also CS Gas Non-Lethal Weapons, Chemical Riot Control Agents. 

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