Cyclotron Institute, Texas A&M University, College Station, TX, USA.

1. Study of the Production of Mo and Tc Medical Radioisotopes Via Proton Induced Nuclear Reaction on natMo Presented By: Abeer Alharbi The 11th international conference on Nucleus-Nucleus collisions Cyclotron Institute, Texas A&M University, College Station, TX, USA. Princess Nora Bent Abdulrahman University, Riyadh, Saudi Arabia. A. Alharbi San Antonio,05/28/2012

2. Importance of Nuclear medicine !! • Radiopharmaceuticals are used extensively in the field of nuclear medicine in three main branches. • The largest and the most common type involve diagnostic procedures • The second deals with radionuclide techniques that are used for the analysis of concentration of hormones, antibodies, drugs and other important substances in samples of blood or tissues. • The third is radiation therapy • In order to keep the exposure dose for the patient as low as possible, the optimization of nuclear reaction for the production of radioisotope is very important. • It involves the selection of: • the Projectile energy range, • the time of irradiation • the cooling time after the EOB: • that will maximize the yield of the produced medical radioisotope and minimize that of the radionuclide impurities. A. Alharbi San Antonio,05/28/2012

3. Importance of Nuclear medicine !! 99Mo is produced through two different methods: 99mTc is produced through the decay of 99mMo via beta decay with a half life of 66 hours. It is interesting to note that 4.52 % of these transitions result in the prompt emission of a 140.5 keVγ-ray from the 7/2+ state of 99mTC. • The usual production of 99Mo for nuclear medicine depends on: • The neutron induced fission of 235U, which results in expensive but high specific activity 99Mo , or • The (n,γ) nuclear reaction with 98Mo, 24% using natural Molybdenum, resulting in inexpensive but low-specific activity 99Mo. A. Alharbi San Antonio,05/28/2012

4. Why this study is important ? • Currently, only five nuclear reactors produce 99mTc (T1/2 = 6.02 h), which is a vital part of diagnostic tests for heart disease and cancer. It accounts for over 80% of all diagnostic nuclear medicine procedures world wide. (The horse of nuclear medicine) • According to the latest survey the world demand for production of 99Mo/ 99mTc is estimated to be around 6000 Ci/week and further growth is predicted. A. Alharbi San Antonio,05/28/2012

5. SPECT - Single photon emission computed tomography is performed by using a gamma camera to acquire multiple 2-D images for the radio tracers inside the body, from multiple angles, which yields a 3-D dataset . The Scanner SPECT image A. Alharbi San Antonio,05/28/2012

6. PET -Positron emission tomography As a positron-emitting radionuclide decays it emits a positron, which promptly combines with electron resulting in the simultaneous emission of two identifiable gamma rays in opposite directions each with 511 keV ENERGY. • Giving a map of functional processes in the body A. Alharbi San Antonio,05/28/2012

7. Animal imaging using 96Tc. A. Alharbi San Antonio,05/28/2012

8. Motivation!! They show relatively large deviations in the maximum value of the cross sections and in the energy position of the maximum as well as in the shape of the excitation function.

9. Experimental Work natMo(P,X)

10. The Experimental setup @ MDM cave Experimental Setup The K500 superconducting cyclotron, Texas A&M Cyclotron Institute was used in the MDM cave. A. Alharbi San Antonio,05/28/2012

11. A photograph for foils and the special aluminum target holders used in the experiment. Experimental Setup A. Alharbi San Antonio,05/28/2012

12. 1- Activation technique Experimental Setup 40 MeV of protons with 20 nA’sintensity Two experiments have been done: 1- To measure the short lived radioisotopes (irradiated for 30 m) 2-To measure the longer lived radioisotopes (irradiated for 50 m) A. Alharbi San Antonio,05/28/2012

13. 2- The Stacked foil technique: Experimental technique stacks were made of several groups of targets(40 foils in each experiment) (natMo, 50 µm) and monitor foils (natAl, 125 µm and natCu, 125 µm) that acted also as beam degraders, the energy step was kept within (0.5-2 MeV). A. Alharbi San Antonio,05/28/2012

14. The produced medical radioisotopes in this study are: (p,xn) (p,pxn) (p,αXn) … etc natMo(p,X) 99Mo 95Nb 99mTc 96Tc Used for SPECT imaging for: Brain, heart , liver, lungs, bones, thyroid and kidney imaging. Also for cerebral blood flow, antibodies, and red blood cells. A. Alharbi San Antonio,05/28/2012

15. The produced medical radioisotopes & the impurities in this study are: (p,xn) (p,pxn) (p,αXn) … etc natMo(p,X) 99Mo 95Nb 99mTc 96Tc 90Mo 90Nb 94Tc 89m,gNb 93m,gTc A. Alharbi San Antonio,05/28/2012

16. Monitor reactions were used to determine the beam energy and intensity Nuclear data

17. Excitation functions of the monitor reactions compared with the recommended cross-sections by the IAEA. Monitor reactions

18. Experimental Results Determination of the actual proton beam Energy:

19. Decay Data & Q-Values for some of the contributing Reactions in the desired Medical radioisotopes production process (1) Nuclear data

20. Decay Data & Q-Values for the contributing Reactions in the desired Medical radioisotopes production process (2) Nuclear data

21. A calibrated Gamma ray spectrum with the identified γ-lines natMo (p,X) TAMU, 2010 661.62 137Cs 849.29 94Tc 140. 51 (99Mo + 99mTc + 90Nb) 810.6 98Nb 778.63 99Mo 765.7 95Tc 509.47 Annihilation 1130.23 96Tc 312.64 96Nb 369.599Mo 202.29 95Tc 907.83 95Nb 178.73 99Mo 1173.24 60Co 391.83 93mTc 483.56 87Y 1332.5 60Co

22. Separation of complex decay of mixture of activities for 140 keV gamma line Experimental results 99Mo, T½= 65.9 h 99mTc,T½= 6.01 h 90Nb, T½= 14.6 h The individual activities of those overlapped γ-rays were analyzed using the difference in half-lives of the contributing nuclides by plotting the γ-ray emission rate as a function of time.

23. Activation formula Whereas: M : Target molecular weight I : Beam intensity Tγ : net area under each γ peak C : The target density f : The abundance Iγ : gamma line intensity

24. Excitation function for natMo(p,X)99Mo nuclear reactions calculated from the measured cross sections in this work: Result & discussions Theoretical simulations using Talys code has been done. A. Alharbi San Antonio,05/28/2012

25. Excitation function for natMo(p,X)95gTc nuclear reactions calculated from the measured cross sections in this work: Result & discussions Theoretical simulations using Talys code has been done. A. Alharbi San Antonio,05/28/2012

26. Excitation function for natMo(p,X)99mTc nuclear reactions calculated from the measured cross sections in this work: Result & discussions A. Alharbi San Antonio,05/28/2012

27. The Integral Yield of the Radionuclide Product Whereas: P : is no. of protons/ μA.h N : is number of target nuclei in cm2 ρ : is surface density in gm/cm2

28. Integral Yields for the natMo(p,x) nuclear reactions calculated from the excitation functions measured in this work: Result & discussions The optimum way to get the maximum yield of 99Mo and the minimum contribution of the impurities is to irradiate with protons @26-29 MeVand wait for 8 Hours after the EOB. 65.9 hr 14.6 hr 51.5 min 43.5 min A. Alharbi San Antonio,05/28/2012

29. NN, 2012 Summary • Stacked foil activation technique used to measure the cross section for the contributed nuclear reactions. • somemonitor reactions have been measured by inserting some foils into the stack . • Theoretical simulations using Talys code. • The integral target Yield for all reactions have been calculated . • The optimum way to get the maximum yield of 99Mo and the minimum contribution of the impurities is to irradiate with protons @ 26-29 MeV and wait for 8 Hours after the EOB. • A considerable discrepancies still exists among the available literature data for the production of medical 99mTc radionuclide, which demands more experimental data to obtain a recommended data set.

30. TAMU Acknowledgment

31. Thank You Thank You for your attention A. Alharbi San Antonio,05/28/2012