Structural Energy Distribution and Particle Phase Stability Study of Longitudinal Dynamics of a Simple Linear Proton Accelerator

This paper presents the study of longitudinal beam dynamics of a simple linear proton accelerator and simulation results for a model linear accelerator (LINAC) using MATLAB. The study part of the transition energy, particle acceleration, transit time factor, RF factor, and momentum compaction are discussed. For the simulation, the model LINAC is built using unit cells and the unit cell consists of Quadrupole doublet and acceleration cavity. Model LINAC’s basic setup is present and the simulation is based on the single-particle analysis. The robustness of the model LINAC tested to operate varying different parameters like initial arrival phase and input energy. The criteria to measure the robustness of the model LINAC are to check the kinetic energy at the end of the LINAC and the transverse stability of the transfer matrices of each cell. The paper also presents the theoretical analysis of phase stability at both below and above transition energy. The stability of small and larger amplitude oscillations are present and simulation results for different particles each starting with different amplitudes observed, where the large amplitude oscillation falls outside of the separatrix.

Structural, spectral and thermal properties of 2,2’-iminodipyridinium(+) trihydrogen pyromellitate

The title compound, (Hdipya)(H3pyr), where Hdipya is protonated 2,2?-dipyridilamine and H3pyr is monoanion of pyromellytic acid (H4pyr), was obtained from the reaction mixture containing Zn(II) ions, dipya, Na4pyr (the molar ratio 2 : 2 : 1) and HNO3. The products (micro- and single-crystalline) were characterized by X-ray structure determination, FT-IR spectroscopy and TG/DSC analysis. The most striking structural feature of (Hdipya)(H3pyr) are short inter- and extremely short intramolecular hydrogen bonds. These bonds mutually connect cations and anions making thin layers parallel to the crystallographic (223) plane. Also, quite unusual, linear proton-bound polymeric {H(H2pyr)-}n anions were identified in the structure. The results of crystal structure determination are compared with FT-IR and TG/DSC data. The low position of nas(COO) vibration at 1660 cm-1 is in accordance with strong hydrogen bonding. This value can be used as a measure of C=O bond order, which is calculated to be 1.81.

EFFECTS OF ALIGNMENT ERRORS IN PROTON NON-SCALING FFAG ACCELERATORS

Non-scaling FFAGs have gained interest in the past decade for their potential application to charged particle therapy using proton and ion beams. However, linear ns-FFAGs naturally cross betatron resonances throughout acceleration. With an acceleration cycle of thousands rather than tens of turns, we find that resonance crossing produces severe orbit distortion in a linear proton/ion ns-FFAG in the presence of alignment errors. To overcome this, the PAMELA (Particle Accelerator for MEdicaL Applications) lattice design avoids resonance crossing with a non-linear ns-FFAG design. This design is outlined and a comparative analysis of alignment tolerances presented.