The existing C-30 cyclotron at NRCAM is currently capable of emitting a proton beam with only Emax=30 MeV. To improve this Emax to higher energies of 250 MeV for proton therapy, this beam is injected into the conceptually designed Medical Proton Synchrotron accelerator. Prior to injection, the beam emittances in both x- and y-directions were measured to be exx=1.76x10-5 m.rad and ey= 5.64x10-5 m.rad. The obtained extracted Twiss parameters at the point of injection were; ax=-1.28, bx=12.7, gx=0.21, ay=-0.55, by=3.28, and gy=0.10. The AGILE computer program code was utilized for the lattice design of the Medical Proton Synchrotron. This design is composed of two achromatic arcs. Each arc bends 180o and has a closed dispersion bump. The designed lattice is composed of eight cells each consisting of two Quadrupoles, one Sextupole and two Dipole magnets. The extraction components of sextupole resonance (SR), electrostatic septum (ES) and magnetic septum (MS) were also placed in the designed lattice. The beta functions, as the main parameters of the lattice, have been chosen to meet requirements of the slow extraction. The working point (Qx, Qy) for adjusting the slow extraction were 1.33 and 2.62, respectively. The Hardt condition was met by minimizing the angular dispersion of the separatists corresponding to a different energy spread. The slow extraction of the accelerated particles was also analyzed. The calculation of the slow extraction is performed using the AGILE program. The obtained lattice Twiss parameters of the focusing structure are also presented.

Background: High and intermediate energy protons are not able to form a track in a solid state nuclear track detector (SSNTD) directly. However, such tracks can be formed through secondary particles created during primary radiation nuclear reactions in a SSNTD. Materials and Methods: The protons with primary energies of 9.6 and 30 MeV available at the cyclotron accelerator with corresponding low LETs of 5.87 and 2.40 keV/mm were taken into consideration. The nuclear tracks etch rate ratio V in CR-39 were measured and transformed into LET spectra for the absorbed and equivalent dose measurements. Results: The optimum etching condition of 6 N NaOH solutions at 65 to 70°C over a 6-hour period for the CR-39 were found initially. The corresponding bulk etching rate reached a steady rate of about 0.62 to 1.3 um/h after nine hours for an optimum etching condition. Although the LET was low, but the energy range seemed sufficient enough to create secondary particles with much higher LET through the nuclear reactions in CR-39. The relative absorbed dose contribution of the created secondary particles to the primary particles for the 9.6 and 30 MeV protons in CR-39 at 1 Gy entrance dose were 7.5 and 29.6%, respectively. Conclusion: The contribution of the secondary particle increased relatively with the proton energy decrease. This phenomenon could modify the characteristics of the energy transfer process due to secondary particles when such particles are used for radiobiological studies and/or for radiotherapy.

Detecting the charge particles at Giga hertz rate is one of the applications of UFSD (Ultra-Fast Silicon Detectors). The UFSD test in front of the proton beam to count the beam particles and use it for a more precise Dose Delivery System for the treatment of the cancerous tumor by charge particles can become an effective step for the development of cancer treatment. In fact, this assessment is a prerequisite and guarantees the use of these detectors in the dose delivery system. In this regard, the best method for time measurement, which was CFD, was chosen. MATLAB software was used to measure and analyze the UFSD output signals. The results of the 50-μm-thick UFSD test and the various geometries that we performed in several different experiments at the CNAO Cancer Treatment Center in Italy, as well as the data obtained at the laboratory of CERN accelerator in Germany, were analyzed by the CFD method. The results of many different runs of programs in MATLAB for many registered signals show: 1- These sensors are reliable to count the proton particles in Giga hertz rate. 2-The CFD devices could be used to record the UFSD output signals. Therefore, they can be used in the correction of the dose delivery system as a counter for the proton number of the proton beam.

Plasma accelerators are using high-energy proton beams as driven beams to produce plasma waves. In this approach, the proton beam energy is transferred through the formed plasma wave to the witness electron beam for achieving high energies. In this paper, using two-dimensional particle simulation, the interaction of a Gaussian high-energy ion beam with plasma containing linear density with a density gradient of 0.03% along the beam propagation direction has been investigated in order to produce a high energy electron beam with excellent quality. To investigate electron acceleration, an 18 MeV witness electron beam is sent to the plasma at the back of the ion beam. The simulation results show that, due to the interaction of the energetic proton beam with plasma, the strong plasma wave field with amplitude 400 MeV/m is created. This field accelerates the trapped electrons of witness beam to high energy gradients of several hundred MeV. Moreover, the evolution of the electron beam emittance as an important parameter in the investigation of the accelerated beam quality, indicates that by considering the appropriate parameters for the plasma, proton and electron beams, the emittance of the witness electron beam grows less than 50% compared to its initial value.

Purpose: To report the development of malignant epiretinal membrane after radiation of ciliary body melanoma. Case report: A 65-year-old woman was referred for evaluation of a ciliary body tumor in her right eye. On examination, a pigmented ciliary body tumor, displacing the iris anteriorly, was visible superotemporally and ultrasound biomicroscopy revealed a large solid ciliary body tumor. She was diagnosed with ciliary body melanoma and treated with proton beam radiation. Over the following 29 months, the treated tumor regressed but optical coherence tomography (OCT) showed the development of a dense epiretinal membrane. Enucleation was performed and histopathological examination showed viable melanoma cells in the vitreous cavity with sheet-like growth of viable spindle melanoma cells on the epiretinal surface. Conclusion: The development of a pigmented epiretinal membrane in eyes with uveal melanoma should raise the possibility of a malignant epiretinal membrane.

Purpose: Proton Beam Therapy (PBT) is an emerging radiotherapy technique using beams of proton to treat cancer. As the first report addressing the topic, the principal aim is to highlight the present status of PBT research and development in Iran as a developing country. Materials and Methods: To do so, the demand for PBT in Iran and Iran National Ion Therapy Center (IRNitc) was investigated and introduced. Then, Scopus and PubMed were searched for studies that dealt with PBT research in Iran and subsequently 6 major subfields of interest were identified. Furthermore, international collaborations were extracted from the bibliographic data. To combine both research and development sides, a SWOT analysis was performed through collecting viewpoints of 48 radiotherapy experts about PBT, and then strengths, weaknesses, opportunities, and threats of it were examined. Results: Iran contributes to approximately 1% of global PBT sciences. Proton dose calculation using Monte Carlo simulation is the dominant subject of interest for Iranian researchers. Italy is recognized as the major foreign partner in PBT researches. Clinical advantages over conventional radiotherapy modalities are the main strength of PBT development in Iran while the high installation cost remains the most weakness. Finally, 10 general considerations for the launching of a PBT facility in Iran were presented based upon both Iranian experts’ viewpoints and IAEA recommendations. Conclusion: This research reveals that while PBT research and development in Iran are still in their infancy, there are promising trends in both the research and development sides of PBT.

Background: In this study, Monte Carlo simulations were performed to estimate the dose of proton therapy to involved and uninvolved organs in gastric cancer. Materials and Methods: The dose received by involved and uninvolved organs during gastric treatment was simulated during pencil beam scanning proton therapy using the MIRD-UF phantom and the MCNPX code. In this modeling, the appropriate energy range for tumor treatment in the gastric tissue of an adult male MIRD-UF phantom with monoenergetic proton beams was calculated. The dose secondary charged particles, neutrons and photons in the tumor and vital organs were evaluated. Results: The results showed that, depending on the size of the tumor, the appropriate and optimal range of proton energy to cover the tumor is 67 - 81.5 MeV. The distribution of energy deposition, total primary dose, and the ratio of neutron equivalent dose to absorbed therapeutic dose (H/D) were calculated for the tumor and 12 vital organs. The ratio between the total received dose of the healthy gastric tissue and the delivered dose of the tumor was about 0.0046. The average photon equivalent dose was about 0.9% of the neutrons. The highest H/D ratios for normal stomach, spleen, pancreas, and left kidney tissue were 0.167 mSv/Gy, 0.0362 mSv/Gy, 0.0231 mSv/Gy and 0.0143 mSv/Gy, respectively. Conclusion: In the study, a small gastric tumor in an adult male phantom was irradiated with high-energy protons. Proton therapy delivered the highest possible dose to the tumor, while the healthy organs received a low dose.

In this research work, commissioning of a radiography end station using proton-induced monochromatic X-rays in the Van de Graaff laboratory of Nuclear Science and Technology Research Institute (NSTRI) is reported. An energetic proton beam with a current of hundreds of nanoamps after passing through the relevant slits in the beam path, is used to irradiate a metallic target leading to the generation of monochromatic X-rays. By altering the target, a wide variety of monochromatic X-rays with different wavelengths could be generated. The yield of characteristic proton-induced X-ray emission is measured using a Silicon Drift Detector (SDD). The generated X-rays could then pass through the window of the reaction chamber and irradiate the sample of interest. In this way, the required conditions for radiography by the “ K-edge contrast imaging” could be provided. By implementing the mentioned analytical technique, using the K-edge absorption of the interest element in the sample, radiographic image contrast could be improved for different samples of cultural heritage such as manuscripts, clothes, and coins in the Van de Graaff lab of NSTRI.

The aim of this work is a description of quantitatively and qualitatively physical processes for proton therapy when a proton pencil beam passes through a water phantom. Therefore, at first, we determine the absorbed dose with both Maple programming and Geant4 simulation in the suggested water phantom. Then, we used as CSDA method to calculate the proton range and range straggling. Also with the Highland formula the mean scattering angle is calculated and following it we investigate the inelastic cross-section, the ionization, and excitation by protons in the inner and outer shells as well as charge transfer, stripping, and ionization by neutral hydrogen.  Finally, we estimate the probabilities of charge state and stopping cross section and straggling and fragmentation. The height, width, and depth of Bragg's peak are discussed through the investigation of collisions, processing, and random phenomena.