<<

The Sixth International Conference "Modern Problems of Nuclear Physics", September 19-22,2006 _ _ _ INP-SO A NARROW- BEAM X - RAY ATTENUATION OF PHOTONS 0.05 - 0.5 MeV IN CHEMICAL

Cherkasov A.S. National University, Kharkov, Ukraine UZ0603199

Basic explosives [1] are - (CeHsNsOg); Hexamethylenetetramine (urotropin) (HMT- C6Hi2N4); 2,4,6 - Trinitrotoluene (TNT - C7H5N3O3); 1,3 - Dinitrobenzene (DNB - C6H4N2O4); Picric acid (2,4,6 - trinitrophenol - C6H3N3O7); TATP (C9Hig06); Hexogen (RDX - C3H6N6O6); Pentaeritronitrate-Nitropenta (PETN - C5H8N4O12); Octogen (HMX - C^NgOg). RDX and/or PETN are usually used in plastic explosives. Examples include C-4, Detasheet, and Semtex). HMX (Octogen) is a very powerful and expensive military , which has been employed in solid-fuel rocket propellants and in military high performance warheads. Currently used military explosives are mostly a combination of TNT, RDX, PETN, HMX, with a number of organic compounds (waxes (e.g. nitroparaffine - C10H8N2O4), plasticizers, stabliers, oil, etc.); example (RDX, TNT), Composition C-4 (or PE-4) (RDX), Detasheet (PETN), Octol (HMX, TNT), Semtex-H (RDX, PETN), etc. (NG - C3H5N3O9)5 Nitrocellulose (QKWMONCfefc. C6H803(ON02)2, C6H9O4(ONO2)) and Ammonium Nitrate (AN - H4N2C>3) are used as a basis of other families of explosives: a) dynamites in 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) gunpowders(guncotton-nitrocotton - collodion cotton, pyroxylinies (e.g. tetranitrate of pulp - colodion wool - C^HigOeONTC^), cordites, ballistites with ammonium perclorate (NH4CIO4) as oxidizer. Dynamites are typically used 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 nitrate (NaNO3), charcoal, and sulphur (it does therefore probably not contain hydrogen). Materials that initiate explosions are hydrazine (N2H4), lead azide (PbN3), trichloride (NCI3), nitrogen (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, nitrourle, nitrocellulose (1,2,3), AN), with the exception of HMT, and for explosive-proof melamine (C3H6N6) and polyurethane (micromolecula - CHNO2) mass attenuation coefficients for photon with energies indicated above are in coincidence in fact with accuracy 1 -3 %. The average values (through 19 kinds of substances) of these mass coefficients ( ,w(cm2/g) = ,'n, •> where o, - the weight part of element / 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 p. 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 300 Section III. Nuclear Applications <^ The Sixth International Conference "Modern Problems of Nuclear Physics", September 19-22,2006 MPNP'2006 1NP-S0 powders, initiative explosives, dangerous and explosion-dangerous gases as well as some widely used organic compounds, for comparison, follow.

Ey, MeV 0.05 0.06 0.08 0.1 0.15 0.2 0.3 0.4 0.5 Substance Group-] 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(CeH6) 0.198 0.187 0.178 0.162 0.145 0.132 0.128 0.104 0.094 Peroxide(H2O2) 0.217 0.206 0.171 0.163 0.143 0.130 0.113 0.098 0.090 Alcogol(C2H6O) 0.218 0.199 0.195 0.171 0.152 0.135 0.116 0.108 0.098 Alcogol(C2H4O) 0.216 0.201 0.185 0.170 0.152 0.138 0.120 0.107 0.098 Eth. GIycol(C2H6O2) 0.213 0.197 0.181 0.167 0.148 0.134 0.116 0.104 0.095 Dieth.Glucol(C4Hi0O3) 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 r0.169 0.151 r 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. (NaNO3) 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) fo.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 Fulm.merc. (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 (Cl) 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.(CH3NO2) 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 (NH3) 0.220 0.207 0.190 0.172 0.157 0.144 0.125 0.111 0.103

Water (H2O) 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.(C5H8O2) 0.205 0.195 0.179 0.163 0.146 0.127 0.115 0.103 0.094 Saccharose (Ci2H22O4) 0.208 0.189 0.180 0.165 0.144 0.131 0.114 0.102 0.093

301 Section III. Nuclear Applications The Sixth International Conference "Modern Problems of Nuclear Physics", September 19-22, 2006 [ MPNF2006 ..... INP-50

Note that in the table the values of /*(cm2/g) for lead azide 1.564 and 6.396 at Ey = 0.088 MeV (X-line) and for fulminate of mercury 1.458 and 5.725 at Ey = 0.083 MeV (iT-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 similar to the so-called dual energy method [3] which is widely used throughout 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., Jsrael 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.-Topics on Atomic Science and Technique . 1999. N° 4. Series: Nuclear-physics studies (35), p.93 - 95.

UZ0603200 TO THE PROBLEM OF THE CORRECT CALCULATION OF THE COULOMB REPULSIVE ENERGY OF CHARGED PARTICLES IN NUCLEI

Cherkasov A.S. National University, Kharkov, Ukraine

The correct calculations of the Coulomb repulsive energy in nuclei of charged particles with charges Ze (Z-l - protons; Z=2 - alpha-particles; clusters and etc.) are important for understanding of the nuclear structure. It is known that in the ground states of nuclei for the description of the particle motion it is possible to use with a good precision the oscillator approximation (approximation of small oscillations), i. e. it is possible to assume that a particle / with mass M and charge Ze moves around its equilibrium position Rt in the central(force) field with potential energy U(r) = 2 Mco ^^ (spherical-harmonic oscillation well potential ) [1], where P = Fi-Ri (f— current coordinate of the particle /); Rjk =| R, -Rk | - an equilibrium distance between particles / and k. As it is known [1] in this case orthonormal particle wave function of the ground state is *F - 2-exp(-orV/2) where a2-n/(Mco2) (in the single-space coordinate case and in classical limit a>=k/M- frequency of the particle-oscillations , &-the elastic constant). The most convenient nuclear objects for investigation of the problem of the correct calculation of the Coulomb repulsive energy of charged particles (in terms of the averaged value)

302 Section HI. Nuclear Applications