Haleema Zainab Department of Physics Govt. College University, Lahore Evaluation of charged particle induced reaction cross section data for the production of 87Y Haleema Zainab Department of Physics Govt. College University, Lahore

Layout Introduction Experimental technique Evaluation methodology Results

Applications of radioisotopes Industry Environment Archeology Agriculture Earth sciences Space sciences Research activities

Radioisotopes in medicine Nuclear Medicine It is a well established branch of medicine that used radioisotopes for diagnosis and treatment of disease. Diagnostic applications Therapeutic applications Theranostic applications Objectives: Imaging: minimum dose (γ or β+ emitters) Therapy: suitable localised dose (βˉ or α-particle emitters)

Applications of 87Y 87Y (T1/2: 79.8 h; EC: 99.8%; Eγ: 388.5 keV (82.2%) and Eγ: 484.8 keV (89.8%)) Gamma rays can be detected by planar or SPECT gamma camera with high-energy, high-resolution collimators. The feasibility analysis of using 87Y as a tracer for in vivo imaging of 90Y-labeled antibodies has been performed by Sgouros  (1998). Sgouros, G. 1998. Yttrium-90 biodistribution by yttrium-87 imaging: a theoretical feasibility analysis. Med. Phys. 25(8), 1487-90. 32 isotopes ranging from 76 to 108 atomic mass number

Applications of 87Y (Contd..) Kutzner et al (1992) shows that a good quality scan can be obtained by using 87Y, that allows the kinetic assessment of the 90Y labeled citrate in the treatment of metastatic bone lesions. 87Y is used as parent radionuclide for making 87Y/87mSr generator. Kutzner, J., Hahn, K., Beyer, G.J., Grimm, W., Bockisch, A., Rosler, H.P., 1992. Scintigraphic use of 87Y during 90Y therapy of bone metastases. Nuklearmedizin. 31, 53–56.

Importance of nuclear data Choice of a radionuclide depends on decay data Suitability for imaging Suitability for therapy Major references NuDat NNDC Table of radioactive isotopes Optimisation of production procedure depends on reaction data Maximise product yield Minimise radioactive impurity level EXFOR Nuclear data= data describing the characteristics of nuclei as well as their interactions

Nuclear reactions 87Sr(p, n)87Y 88Sr(p, 2n)87Y 85Rb(α, 2n)87Y natZr(d, x) 87Y

Experimental Technique….

Stack foil activation technique

Stack design First stacks Second stack Energy: 50-25 MeV Target: nat Zr (25µm) Monitor: natTi, natFe (25µm) Degrader: Aluminum Beam current: 100nA Time of irradiation: 20 min Second stack Energy: 30-0 MeV Target: nat Zr (25µm) Monitor: natTi, natNi (25µm) Degrader: Aluminum Beam current: 100nA Time of irradiation: 20 min

Stack design

Steps for stack preparation Cutting of foil (25×25mm) Measurement of dimensions and weight Cleaning of foils Wrapping of foils in Kapton tape Labeling of foils Mounting on frame Kapton films can withstand extreme temperature from 269°C to 260°C and can mask uneven surface of foils due to its unique combination of thermal, electrical, mechanical and chemical properties.

Beam size verification Beam size and position was verified prior to actual irradiation by Phosphors plate Irradiatation of Gafchromic films

Gamma spectroscopy Spectroscopy Efficiency & energy calibration HPGe detector coupled to PC based analyzer Mestro Ortec. Efficiency & energy calibration 152Eu, 137Cs, 56Co and 133Ba Peak fitting Radware

Activation formula λ : Decay constant of radionuclide (S-1) C : Counts under peak area of desired radionuclide ε : Efficiency of HPGe detector Iγ : Intensity of gamma line or branching ratio tm : Spectrum acquision or measurement time (S) ti : Itrradiation time (S) tc : Cooling time (S) n : Number of particles in target (#/cm2) φ : Beam flux (S-1)

Beam energy measurement Anderson & Ziegler (A&Z) formalisms SRIM code Spectroscopic data from monitor foils

Beam energy measurement Activation of natTi foil produces 48V and 46Sc by reactions natTi(d,x)48V and natTi(d,x)46Sc φ1=φ2 n1=n2

Calculation of beam Intensity  

Evaluation methodology….

Evaluation methodology Charged particle data evaluation methodology is developing, mainly co-ordinated by IAEA. It involves Compilation of data (EXFOR) Normalisation of data (decay data, monitor cross section, etc.) Nuclear model calculation (ALICE-IPPE, TALYS, EMPIRE ) Statistical fitting of data Role of nuclear model calculations Validation of experimental data Guidance in rejection of inaccurate data Prediction of unknown data Neutron data extensively evaluated, mainly for energy research; also useful in reactor production of radionuclides 25

Results Production routes of 87Y

Isotopic impurities (%) Reaction Energy range (MeV) Yield (MBq/μAh) Isotopic impurities (%) Reference   88Y 87mY 87Sr(p,n)87Y 120 3.6 1.4 - Allen & Pinajian, 1965 142.7 104 0.008 468 This work 88Sr(p,2n)87Y 2620 101 0.4 Janssen et al., 1986 2820 219 0.22 441 85Rb(α,2n)87Y 350 2.2 3 Hillman et al., 1966 7.4 1.6 Homma et al., 1980 9.8 0.08 515

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