Influence of reaction channel on the isomeric cross-section ratio
Summary The influence of reaction channel on the isomeric cross-section ratio was investigated by analysing the experimental data on the reactions 52Cr(p, n)52m,gMn, 52Cr(3He, t)52m,gMn, 54Fe(d, α)52m,gMn, 54Fe(n, t)52m,gMn and 54Fe(3He, α p)52m,gMn over the incident particle energy range extending up to 35 MeV. The influence is most pronounced when the channels differ widely, for example (p, n) and (3He, t) processes, i.e. when the reaction mechanisms are different. The nuclear model calculational code EMPIRE-II described the isomeric cross-section ratio rather well in the case of a simple nucleon emission reaction, but not when complex reaction channels were involved.
Investigation of 50Cr(d,n)51Mn and natCr(p,x)51Mn processes with respect to the production of the positron emitter 51Mn
The positron emitter 51Mn (t1/2 = 46.2 min, Iβ+ = 97%) is of potential interest in positron emission tomography (PET). With a view to optimizing its production route, excitation functions for deuteron induced nuclear reactions on isotopically enriched (~95%) 50Cr were determined radiochemically over the energy range of 3 to 13 MeV and for proton induced nuclear reactions on natCr in the range of 18 to 38 MeV. Cross sections are presented for the reactions: 50Cr(d,2n) 50mMn, 50Cr(d,n) 51Mn, 50Cr(d,t)49Cr, 50Cr(d,p)51Cr, 50Cr(d,a)48V, 52Cr(d,2p)52V, natCr(p,x) 51Mn, natCr(p,x)52Mn, natCr(p,x)52mMn, natCr(p,x)54Mn, natCr(p,x)48Cr, natCr(p,x)49Cr, natCr(p,x) 51Cr, natCr(p,x)48V and natCr(p,x)45Ti. In the case of proton induced reactions on natCr, the isomeric cross section ratio for the isomeric pair 52m,gMn was also determined. The results are interpreted in terms of the spins of the two isomers concerned. Theoretical thick target yields were derived from the corresponding excitation functions. The maximum achievable thick target yield of 51Mn is 1.1 GBq/μAh in the case of the 50Cr(d,n) 51Mn reaction at Ed = 14 → 3 MeV, and 3.2 GBq/μAh in the case of the natCr(p,x)51Mn process for Ep = 40 → 20 MeV. The 50Cr(d,n) 51Mn process is the favourable production route for 51Mn, since the radioisotopic purity is high and a small-sized medical cyclotron is adequate to produce this positron emitter in sufficient quantities.
SMC composites waste management as reinforcing fillers in polypropylene by combination of mechanical and chemical recycling processes
A new process of management of waste of composite materials from Sheet Moulding Compounds (SMC), as reinforcing fillers for thermoplastic materials, including both mechanical and chemical processes is proposed in this paper. Communited SMC being composed of coated glass fibres intimately mixed with calcium carbonate powder, their reinforcing power is low. First, the fibrous part was increased by partial dissolution of calcium carbonate present in the crushed products SMC. Second, a process of partial solvolysis was developed aiming at strong increasing the interfacial mechanical properties by functionalising of SMC load incorporated into polypropylene/grafted maleic anhydride polypropylene (PP/PPgma). At this effect, we investigated a treatment with a hot triamine (diethylenetriamine, DETA) in order to create a functionalisation, after scission of the bond ester of unsaturated polyester, as bridging amino-succinimide.The effect of this recycling way by partial solvolysis was checked from the mechanical properties of the resulting reinforced PP/PPgma material: Although a lower of Young modulus, better yield stress and especially resilience were observed.