Photofission of 238-U Nuclei

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1 Photofission of 238-U Nuclei International Thorium Energy Conference - ThEC18, 29-31st of October 2018, Belgium İsmail Boztosun This research has been supported by TÜBİTAK with grant number 114F220

2 Motivations i. Personal: From Theory to Experiment ii. No dedicated research accelerators in developing world: Use of medical Linacs - Advantages of having Good total photon flux i. Fundamental Nuclear Science ii. Aplication of Nuclear Tecniques iii. Tranining & education facility for the PhD and MSc students

3 OUTLINE A New Landscape for developing countries, Nuclear Reactions & structure Proton Rich Nuclei and PR and GDR measurements Photonuclear and Photofission Reactions, Experimental setup Electron Linac Detectors Results Summary & Outlook NUBA

A landscape for Nuclear Reseach at 126 Developing Countries with Medical Linacs ~2000 KNOWN NUCLEI 82 8 2 protons 2 28 20 8 20 Stable nuclei less than 300!

4 A landscape for Nuclear Reseach at 126 Developing Countries with Medical Linacs ~2000 KNOWN NUCLEI protons Stable nuclei less than 300! Limits of existence mass, charge & ratio N/Z 50 spin & temperature extremes shapes neutrons The nucleus : a laboratory for fundamental interactions and symmetries Shell structure and Isospin Spin and shapes Key nuclei for stellar processes are far from stability High energies - Current Accelerators Still interesting research for low energy charged particle and photon reactions

5 PHOTONUCLEAR REACTIONS a A B b B + b target projectile product ejectile

6 Prompt Neutron Gamma h n Ga delayed Ga Target nuclide Compound nucleus Product nuclide level

reactions are obtained using a Electa TM

Primary electron beam is generated by an

Then the beam accelerated in a copper cavity

radio-frequency with peak power of about 5 MW.

30 μa for an electron energy of about 10 MeV,

400 pulses per second and a pulse length of 3

7 Medical Electron Linear Accelerator Bremsstrahlung photons for photonuclear reactions are obtained using a Electa TM Synergy TM accelerator, SLi-25. Primary electron beam is generated by an electron gun with 50 kev electrons. Then the beam accelerated in a copper cavity by a 3 GHz (2856MHz to be exact) radio-frequency with peak power of about 5 MW. The typical average electron current is about 30 μa for an electron energy of about 10 MeV, The SLi-25 is a pulsed linear accelerator with 400 pulses per second and a pulse length of 3 micro seconds. The steering and focusing of the beam is achieved by standard magnetic and electrostatic devices.

8 The bremsstrahlung field; lateral homogeneity h e - Spatial beam uniformity at y=0 along the x-axis Measurement performed with a matrix of 32x32 ion chambers for 2 s. Longer measurement times reduce the variations.

9 Bremsstrahlung spectrum at sample position

DETECTORS DATA ACQUISITION A p-type, coaxial, electrically cooled, HPGe

ORTEC bias supply, spectroscopy amplifier, analog to digital converter

Placed into a 10 cm thick lead shield with an inner surface covered by

Emitting gamma rays in the energy range between 47 and 1836 kev is

10 DETECTORS DATA ACQUISITION A p-type, coaxial, electrically cooled, HPGe gamma-ray spectrometer 40% relative efficiency and 768 ev FWHM at 122 kev for 57 Co and 1.85 kev FWHM at 1332 kev for 60 Co Connected to a NIM consisting of ORTEC bias supply, spectroscopy amplifier, analog to digital converter and a computer. Placed into a 10 cm thick lead shield with an inner surface covered by a 2 mm thick copper foil to shield from the X-rays originating in lead Emitting gamma rays in the energy range between 47 and 1836 kev is rutinely used for energy calibration. Configured with channels and the gain is adjusted: energy resolution is about 0.18 kev giving a range of detected energies up-to about 3000 kev.

11 PHOTONUCLEAR REACTIONS Ga-69: 60.1% Ga-71: 39.9%

12 THE GALLIUM EXPERIMENT: GAMMA SPECTRUM

13 THE GALLIUM EXPERIMENT: ENERGY LEVELS

14 THE PRASEODYMIUM EXPERIMENT: ENERGY LEVELS

15 THE SCANDINIUM EXPERIMENT: ENERGY LEVELS

16 HALF-LIFE FITS Secular equilibrium is assumed i.e. T 1/2 parent >> T 1/2 daughter min, h, d >> ns, ps

17 HALF-LIFE RESULTS Isotope NUDAT T 1/2 σ NUDAT T 1/2 σ 68 Ga m m Ga h h Pr 3.39 m m Pr h h Sc*(1157) h h 6 44 Sc(1157) 3.97 h h Sc*(271) h h 1.5 for multi-isotop elemements (Ga) we get some systematic error ~10% for single isotop elements (Pr, Sc) we are in agreament with the literature and can have similar uncertanties

18 THE DECAY OF SCANDİNİUM: (No-secular equilibrium!)

19 Photo-fission of Uranium-238 Materials

20 Photo-fission of Uranium-238 Stage 1- To perform photo-fission of the target nuclei Uranium-238, inside compound UO2(NO3)2, was prepared with appropriate geometry for irradiation and detection of the yield with the HPGe detector. Stage 2- The target was irradiated for 1 hour with 18 MeV bremsstrahlung photons obtained from e-linac. Stage 3- Fission yield data resulted from photo-nuclear reaction were counted for two days with HPGe. Stage 4- The spectrum was analyzed to identify the photo-fission yields. The energy and the area of the each peak and half lives of the nuclei of the peaks were determined.

Results Photo-Fission Yields Energy (kev) 134Te 210.573 94Y 917.7587 136Pr 999.8549 142Ba 255.

21 Results Photo-Fission Yields Energy (kev) 134Te Y Pr Ba Ba Ba Ba Xe Xe Tc Tc Tc

22 SUMMARY & OUTLOOK A unique research center having an accelerator that is capable of performing spectroscopy and instrumentation Important to promote Nuclear Science at devoloping countries Tranining and education facility for the PhD and MSc students: i.e. For the case of Turkey, CERN membership, Nuclear & HEP studies Material hardening, space radiation and detector studies: compton background test for AGATA and ELI-NP Nuclear Reactions: (,n) (,p) (, ) and (, ) for PR and GDR Energy Levels and Half-life measurements for proton rich nuclei: Better results Nuclear structure: level densities and transitions Nuclear structure: Shape-Phase transitions Nuclear Astrophysics: Nucleosynthesis for early universe Applications of Nuclear Techniques from Archeology, Engineering to

23 Outcomes: First photonuclear paper with local resources

24 TUBITAK VISITING SCIENTIST PROGRAMME Visiting Scientists/researchers on Long term Long-term fellowships fund is available for the following activities in Turkey: Conducting research and development (R&D) Scientists/researchers on SABBATICAL LEAVE (3 to 12 months): Scholars or academic staff on SABBATICAL LEAVE planning to come to any Turkish university/institution is also funded Requirements for Beneficiaries: Fellows can be citizen of any country. Fellows should have a PhD degree (or equivalent) Fellowship Details: A monthly stipend of up to US$ for Visiting Scientists. A monthly stipend of up to US$ for Visiting Scientists on Sabbatical Leave Travel costs (round trip) and health insurance premiums.

25 This research has been supported by TÜBİTAK with grant number 114F220

Turkey s first photonuclear reactions performed at Akdeniz University: Matter, Anti-matter, Pure Energy and Alchemy

(Ülkemizin ilk fotonükleer reaksiyonu Akdeniz Üniversitesinde gerçekleştirildi: Madde, Anti-Madde, Saf Enerji ve Simya) Turkey s first photonuclear reactions performed at Akdeniz University: Matter, Anti-matter,