Radionuclide production measurements at the INFN LNL Giacomo Germogli INFN Section of Ferrara
Monday, March 18, 2019 2 History • 2014/2015, collaboration with COMECER SpA: • Anti-channeling idea • “ Exploiting Channeling of Charged Particles for the Enhancement of the Ni64->Cu64 Reaction Yield ”, 7 June 2015, Society of Nuclear Medicine and Molecular Imaging Meeting 2015, Baltimore (US) • 2016/2017, INFN-GeCO (Geant4 Crystal Objects) project: • Integration of channeling simulations into Geant4 • Anti-channeling experiments at INFN-Legnaro Laboratories • “ Crystalline targets for the enhancement of the nuclear interaction yield ”, 15 November 2016, International Nuclear Target Development Society Meeting 2016, Cape Town (South Africa) • “ Experimental measurement of the enhancement of the nuclear interaction yield with crystalline targets ”, 13 June 2017, International Conference on Applications of Nuclear Techniques, Crete (Greece) • 2017/2019, POR-FESR TROPIC project • Development of a target prototype for the production of radioisotopes for medical interest, to be tested in laboratory environment (TRL4) and in production environment (TRL5)
Monday, March 18, 2019 3 RBS-Channeling at AN2000 INFN-LNL AN2000 is an electrostatic-type accelerator with a maximum voltage terminal of 2 MV. At the RBS- Channeling line of AN2000 (CN) a high resolution goniometer (0.01° ~ 0.2 mrad) is present, which allows to align the crystal planes and axes with respect to the incoming beam within the critical channeling angle. D. De Salvador • Two Silicon detectors are mounted in the chamber, one for the RBS and one for the nuclear resonance analysis (NRA), to allows for the simultaneous measurement of the two quantities. Optionally a gamma- ray detector can be mounted instead of the NRA detector. CSN5 Grant for young researchers – E. Bagli
Monday, March 18, 2019 4 Al 2 O 3 crystal We decided to use a nuclear reaction with a resonance at energy accessible by the AN2000 accelerator. The chosen reaction is the 18 O (p,α) 15 N reaction at ~627 KeV 1 with a Q- value of ~4.0 MeV. • We choose the Al 2 O 3 aluminum oxide C-plane wafer for the experiment, i.e. the <0001> direction, that has an hexagonal crystal structure. CSN5 Grant for young researchers – E. Bagli
Monday, March 18, 2019 5 Al 2 O 3 crystal - NRA Al 2 O 3 substrates, <0001> axis, 18 O(p,α) 15 N reaction CSN5 Grant for young researchers – E. Bagli - UNPUBLISHED
Monday, March 18, 2019 6 INFN LNL-Tandem accelerator The proposal for the TROPIC experiment at the Tandem accelerator of the INFN Legnaro National Laboratories, PD, Italy was accepted by the USIP . This represents the “validation in lab” (TRL4) Tandem-XTU is an electrostatic-type accelerator. The High Voltage Terminal (HVT), which exceeds 13.5 MV positive voltage as the maximum operational electrostatic value, is located at the center, and along the longitudinal axis, of a horizontal tank After the beam extraction to the +50 Sliding Seal line, a double Tantalum pinhole allows to collimate the incoming beam. Gamma emission of tantalum is screened with 2mm of plain Ta. www.lnl.infn.it
Monday, March 18, 2019 7 Measurement setup • One Silicon detector (area = 50 mm 2 , thickness = 2mm ) is mounted into the chamber for measuring backscattered particles at +40° A high resolution goniometer (0.01° ~ 0.2 mrad) is present, which allows to align the crystal planes and axes with respect to the incoming beam within the critical channeling angle. For p + @13 MeV: • One HPGe Germanium detector with Ge (100): θ L =1.242 mrad GASP preamplifier is mounted far (≈ Ge (111): θ L =1.574 mrad 2m) outside the chamber to measure prompt gamma emitted γ -rays upon Ge (110): θ L = 1.593 mrad de-excitation of produced nuclei
Monday, March 18, 2019 8 Setup scheme for laboratory validation LNL Tandem – top view Ge detector Crystal support (Si) p + @ 13 MeV Goniometer Ta collimator Crystal (e.g. Ge, Simox) Si detector
Monday, March 18, 2019 9 Method for production measurement Prompt gamma Nuclear radiation detected excited states through HPGe detector Energy ≈ MeV (p,n γ ) t 1/2 ≈ fs÷ns Total charge detected Final isotope (e.g. 89 Zr) through faraday cup (p,p ’γ ) β + decay t 1/2 ≈ hours÷days Target isotope (e.g. 89 Y)
Monday, March 18, 2019 10 Ge (001) bulk – planar channeling (1-10) r y Si detector <001> r x (110) (1-10) Surface backscattering 3000 2500 2000 integral / 1uC 1500 1000 500 0 -0,2 -0,1 0 0,1 0,2 0,3 theta (°)
Monday, March 18, 2019 11 Si detector Ge (001) thin #3 r y <001> r x (110) (1-10) HPGe
Monday, March 18, 2019 12 Es: 76 Ge(p,n) 76 As from nat Ge target E γ = 669 keV (p,n) 76 As 76 Ge HPGe
Monday, March 18, 2019 13 Upgrade of the chamber Sample holder(s) Ge detector Coin (Pt, Nb, …) Collimator (s) p + @ 10-15 MeV Target (e.g. Y) Goniometer Si detector
Monday, March 18, 2019 14 Possible measurement • Target quality and composition via Elastic Backscattering analysis (EBS) • Nuclear interaction rate via quantitative measurement of prompt gamma rays • Current normalized with the polarizable targe station • Nuclear interaction rate normalized via standard reaction reference • Setup improvement required: • Set of custom made sample holders • Set of collimators • Silicon detector for elastic backscattering
Monday, March 18, 2019 15 BACKUP SLIDES
Monday, March 18, 2019 16 Outline • Radionuclide productions in accelerators • A benchmark for simulations: the GECO project • The INFN TTLab TROPIC Project • Development of a crystalline target • Validation in laboratory environment • Setup for future measurements
Monday, March 18, 2019 17 Radioisotopes in Medicine • Nuclear medicine uses radiation to provide diagnostic information about the functioning of a person's specific organs (SPECT, PET), or to treat them (Brachytherapy, target- therapy), especially for cancer. Diagnostic procedures using radioisotopes are now routine. • Over 40 million nuclear medicine procedures are performed each year, and demand for radioisotopes is increasing at up to 5% annually. • Radioisotopes for nuclear medicine are generated through various methods, i.e. particle accelerators, reactors facilities
Monday, March 18, 2019 18 Accelerator produced radionuclides • Current scenario: • Strong reduction of the production of Mo-99 (i.e. the parent daughter of TC-99m) in nuclear reactors • Advantages of accelerators: • high specific activities can be obtained through charged particle induced reactions • few radioisotopic impurities by selecting the energy window • small amount of radioactive waste generated • access to accelerators is much easier than to reactors • Major drawback: • in some cases an enriched (and expensive) target material must be used • The overall production cost is still 3 to 10 times with respect to nuclear reactors
Monday, March 18, 2019 19 Anti-Channeling Effect • Figures show the Geant4 simulated trajectories of channeled and anti-channeled 655 keV protons impinging on a Si (110) crystal. • A particle which enters parallel to the crystalline planes, bounces between them, in a region without nuclei. • At the opposite, the particles with the angle close to the critical angle for channeling cross the crystal planes (red dashed line) and impinge close to atomic nuclei. CSN5 Grant for young researchers – E. Bagli
Monday, March 18, 2019 20 Anti-Channeling Effect Enrico Bagli - CSN5 Grant for young researchers
Monday, March 18, 2019 21 Radioisotope for medicine • Radioactive isotopes used Target Initial Isotope Final Isotope for diagnosys, therapy, or 89 Y 89 Y 89 Zr both (theragnostic) TeO 2 124 Te 124 I • Lifetime of the order of TeO 2 123 Te 123 I biologial processes (few hours/days) SrCO 3 86 Sr 86 Y 64 Ni 64 Ni 64 Cu • Possibility to fix them to a 61 Ni 61 Ni 61 Cu functional molecule 111 Cd 111 Cd 111 In 44 Ca 44 Sc CaCo 3 • To be produced with a good yield by using 67 Zn 67 Zn 67 Ga particles at energies available at commercial 68 Zn 68 Zn 68 Ga cyclotron (~15-20 MeV)
Monday, March 18, 2019 22 Characteristics of the crystalline target • Isotopic purity needed to obtain • A crystalline quality sufficiently a good yield of production high to observe the anti- without contaminants. channeling effect • Yttrium and Rhodium have only one isotope, they can be found as crystalline material, and are useful materials for nuclear medicine: • Pros: No need to be enriched • Cons: to be found as a pure monocrystal (expensive/not trivial) • First Y (2x2x0,5 mm) and Rh (3x3x0,5mm) already purchased, characterized and polished are the first candidates as a target.
Monday, March 18, 2019 23 Surface realignment and polishing Surface Preparation Laboratory (Netherlands) Microscope Diffraction Microscope Diffraction Rhodium as received Yttrium as received After polishing After polishing
Monday, March 18, 2019 24 Other ionic/oxide/semiconductor crystals • KBr (cubic structure) • YAG, YAlO 3 , YVO 4 • Ge (fcc structure)
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