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KapflHHajibHMM peiueHHeM 3TOH npo6jieMU HBJM- 0113 eTCH pa3pa6oTKa CHCTCMW zmcKpHMHHauHH y-^ ' npHHUHn fleficTBHa KOTopofi ocHOBaH Ha CymeCTBCHHOM pa3JIHHHH yfl&IIbHOH HOHH3aUHH, BbI3BaHHOH npOTOHOM OTflaHH OT HeirrpoHa n sjieinpoHOM, o6pa3yiomHMCfl npn B3aHM0fleHCTBHH Y-KBairra c BemecTBOM. OflHaKO JlO C03flaHHH TaKOH CHCTeMbI Heo6xOflHMO 6bIJIO HCCJieflOBaTb B03MOHCHOCTb flHC- 0Ha 1 KpHMHHauHH Y- A NARROW- BEAM X-RAY ATTENUATION OF PHOTONS 0,05-0,5 MeV IN CHEMICAL EXPLOSIVES A .S. Cherkasov Kharkov National University, Ukraine [email protected] Basic explosives [1] are - Tetryl (C6H5N5O8); Hexamethylenetetramine (urotropin) (HMT - C6H12N4); 2,4,6 - Trinitrotoluene (TNT - C7H5N3O3); 1,3 - Dinitrobenzene (DNB - C^UN204)\ Picric acid (2,4,6 - trinitrophenol - C6H3N3O7); TATP (C9Hi806); Hexogen (RDX - C3H6N606); Pentaeritronitrate-Nitropenta (PETN - C5H8N4O12); Octogen (HMX - C4H8N808). RDX and/or PETN are usually used in plastic explosives. Examples include C-4, Detasheet, and Semtex). 327 CeKUfim 5 HMX (Octogen) is a very powerfull and costly military explosive, which has been employed in solid-fuel rocket propellants and in military high performance warheads. Military explosives cur• rently used are mostly a combination of TNT, RDX, PETN, HMX, with a number of organic compounds (waxes (e.g. nitroparaffine - C10H8N2O4), plasticizers, stabliers, oil, etc.). Examples are Composition B (RDX, TNT), Composition C-4 (or PE-4) (RDX), Detasheet (PETN), Octol (HMX, TNT), Semtex-H (RDX, PETN), etc. Nitroglycerin (NG - C3H5N3O9), Nitrocellulose (C6H702(ON02)3, C6H803(ON02)2, C6H904(ON02)) and Ammonium Nitrate (AN - H4N2O3) are used as a basis of other families of explosives: a) dynamites in the case of NG with nitroglycol (C4H8N2O2), powders of Al or Mg, with TNT and ammonal (TNT with Al-powder), wood flour, etc.; b) white(smokeless) gunpow- ders(guncotton-nitrocotton - collodion cotton, pyroxylinies (e.g. tetranitrate of pulp - colodion wool - Ci2Hj606(N03)4), cordites, ballistites with ammonium perclorate (NH4CIO4) as oxidizer. Dynamites are used typically as a high explosive for industrial applications and in solid rocket propellants. Note that pure AN does not contain carbon; it has been widely used to fabricate bombs, but it is also widely diffused as a fertiliser. Ethylene glycol dinitrate (EGDN - C2H4N2O6) is a trasparent, colourless liquid explosive, which has been used in mixtures with NG for low- temperature dynamites. Its use has greatly decreased due to the replacement of dynamites with ammonium nitrate-fuel oil (ANFO) and slurry explosives. Black powder is a low-order explosive consisting of potassium nitrate (KNO3) or sodium ni• trate (NaN03), charcoal, and sulphur (it does therefore probably not contain hydrogen). Materials that initiate explosions are hydrazine (N2H4), lead azide (PbN3), nitrogen trichlo• ride (NCI3), nitrogen triiodide (NJ3), fulminate of mercury (Hg(ONC)2). An analysis of mass narrow-beam X-ray attenuation coefficients for photons 0,05-0,5 MeV which were carried out on the basis of handbook [2] shows: 1. For 17 basic kinds explosives as well as for the second explosives (TNT, NG, Octogen, Hexogen, Picric acid, pyroxylines (1,2), Tetyl, PETN, nitronaphtalene, nitroglycol, EGDN, nitro- urle, nitrocellulose (1,2,3), AN), with the exception of HMT, and also for explosive-proof mela- mine (C3H6N6) and polyurethane (micromolecula - CHNO2) mass attenuation coefficients for photon with energies indicated above are coincidenced in fact with accuracy 1-3 %. The average values (through 19 kinds of substances) of these mass coefficients (u(cm7g) = £u,f- -n,, where n; - the weight part of element i in the chemical combination) are in this table (Group 1). The most divergences from average values are for AN and melamine (-4,8 % at 0,06 MeV and -6,5 % at 0,5 MeV accordingly). The more of hydrogen, the more value of u. In the table the group of materials used for production explosives or fire- and explosion- dangerous ones adjoins to group 1 with HMT. Then the substances used for production black powders, initiative explosives, dangerous and explosion-dangerous gases as well as some widely used organic compounds, for comparison, follow. £y, MeV 0,05 0,06 0,08 0,1 0,15 0,2 0,3 0,4 0,5 Substance Group-1 0,204 0,187 0,170 0,157 0,139 0,125 0,109 0,098 0,089 HMT 0,203 0,197 0,176 0,164 0,139 0,133 0,116 0,104 0,101 Benzine(C6H$) 0,198 0,187 0,178 0,162 0,145 0,132 0,128 0,104 0,094 Peroxide(H202) 0,217 0,206 0,171 0,163 0,143 0,130 0,113 0,098 0,090 328 Texnuxa u Memodbi xdepHO-tpiaunecKoeo SKcnepuMeHma Conclusion table Alcogol(C2H60) 0,218 0,199 0,195 0,171 0,152 0,135 0,116 0,108 0,098 Alcogol(C2H40) 0,216 0,201 0,185 0,170 0,152 0,138 0,120 0,107 0,098 Eth. Glycol(C2H602) 0,213 0,197 0,181 0,167 0,148 0,134 0,116 0,104 0,095 Dieth.Glucol(C4H10O3) 0,211 0,196 0,181 0,166 0,148 0,131 0,117 0,104 0,096 Urle (CH4ON2) 0,207 0,189 0,175 0,162 0,144 0,131 0,114 0,085 0,076 Am.perchl.(NH4C104) 0,338 0,264 0,201 0,174 0,144 0,128 0,110 0,098 0,086 Sodium (Na) 0,275 0,224 0,179 0,158 0,134 0,120 0,103 0,092 0,084 Magnesium (Mg) 0,320 0,253 0,193 0.168 0,130 0,124 0,107 0,095 0,086 Aluminium (Al) 0,355 0,270 0,200 0,169 0,138 0,122 0,104 0,093 0,084 Potassium (K) 0,836 0,550 0,320 0,233 0,159 0,132 0,108 0,095 0,086 Carbon (C) 0,186 0,175 0,169 0,151 0,135 0,123 0,107 0,096 0,087 Sulphur (S) 0,562 0,393 0,254 0,199 0,150 0,130 0,109 0,097 0,088 Sod. Nitrate. (NaN03) 0,201 0,197 0,170 0,154 0,135 0,122 0,106 0,095 0,086 Potas. nitrate (KNO3) 0,444 0,327 0,226 0,185 0,145 0,117 0,108 0,095 0,087 Hydrazine (N2H2) 0,213 0,199 0,182 0,171 0,151 0,138 0,120 0,107 0,067 Lead azide(PbN3) 6,634 4,096 1,985 4,575 1,679 0,839 0,346 0,202 0,147 Nitrog. trichlor.(NCl3) 0,575 0,395 0,253 0,196 0,146 0,126 0,105 0,093 0,085 Nitrogen triiodite(NJ3) 11,77 7,890 3,372 1,882 0,687 0,363 0,174 0,122 0,097 Fulmmerc. (Hg(OC)2) 5,327 3,312 1,639 3,726 1,373 0,697 0,298 0,182 0,134 Hydrogen (H) 0,335 0,326 0,308 0,294 0,265 0,243 0,211 0,189 0,173 Oxygen (0) 0,210 0,189 0,167 0,155 0,136 0,123 0,107 0,096 0,087 Chlorine (CI) 0,625 0,426 0,265 0,202 0,148 0,126 0,105 0,093 0,084 Methane (CH4) 0,223 0,213 0,204 0,186 0,168 0,153 0,133 0,113 0,108 Nitrocarbin.(CH3N02) 0,210 0,191 0,173 0,161 0,142 0,129 0,112 0,100 0,090 Acetylene (C2H2) 0,198 0,187 0,180 0,177 0,143 0,134 0,117 0,103 0,093 Ammonia (NH3) 0,220 0,207 0,190 0,172 0,157 0,144 0,125 0,111 0,103 Water (H20) 0,224 0,204 0,183 0,171 0,151 0,137 0,119 0,106 0,097 Polyethylene (CH2) 0,207 0,197 0,180 0,171 0,153 0,140 0,121 0,102 0,099 Polystyrene (C8H8) 0,197 0,188 0,180 0,162 0,145 0,132 0,115 0,103 0,093 Pol.Methac.(C5H802) 0,205 0,195 0,179 0,163 0,146 0,127 0,115 0,103 0,094 Saccharose (C12H22O4) 0,208 0,189 0,180 0,165 0,144 0,131 0,114 0,102 0,093 Note that in the table the values of u,(cm /g) for lead azide 1,564 and 6,396 at Ey = 0,088 MeV (K-line) and for fulminate of mercury 1,458 and 5,725 at Ey = 0,083 MeV (K-line) are not indicated. 2. From this table you can see that mass attenuation coefficients for the basic (first) group of explosives are the least with the exception, of course, of helium, lithium, beryllium, boron, carbon and nitrogen. The results of analysis can be used for designing of X-ray customs techniques for finding out of explosive's presence in the luggage without recognizing of the type of the explosive's material (group 1). The method is like to so-called dual energy method [3] which is widely used through- 329 CetofuxS out the world in X-ray customs inspection systems for luggage control in airports is impossible to except from our consideration. References 1. Grodzins L. Nuclear techniques for finding chemical explosives in airoport luggage. Nucl. Instr. and Meth. in Phys. Research, B56/57.1991. P. 829-833. 2. Storm E., Israel H. Photon Cross Section from 0.001 to 100 MeV for Elements 1 through 100. Los Alamos Scientific Laboratory. New Mexico. 1967. 3. Novikov V., Ogorodnikov S., Petrunin V. Dual energy method of material recognition in high energy introscopy systems. Bonpocw aTOMHoft HayKH H TexHHKH. 1999. Jfs 4. Cep.: .SflepHo- (bH3HiecKHe HccjieflOBaHH* (35). C.93-95. 330