Fully differential study of higher-order contributions to the few-body dynamics of simple atomic systems

”Advancing our understanding of the few-body dynamics in simple atomic systems is one of the most important goals of atomic scattering research. In perturbation theory, this goal entails accurately describing the relative contributions from first versus higher-order mechanisms. One higher-order mechanism that is particularly important for target ionization by a charged-particle impact is known as post-collision interaction (PCI). There, the projectile and the ejected electron interact with each other at least twice. In the first interaction, the projectile transfers sufficient energy for the electron to be lifted to the continuum. The second interaction occurs in the outgoing part of the collision, where the projectile and the electron attract each other towards the initial beam axis. It is well known that PCI maximizes when the electrons are ejected with a speed close to that of the projectiles. However, a systematic study on a fully differential level of ionization by ion impact was lacking for this kinematic regime. Kinematically complete experiments on ionization of H2 and He by 75 keV proton impact were performed. Fully differential cross sections (FDCS) were extracted for a broad range of fixed electron energies for each of the targets. Pronounced post-collisional effects between the projectile and the ejected electrons were observed. The results were compared with two conceptually similar calculations, both based on distorted wave approaches. Surprising discrepancies were observed between the experimental data and theory, and also between conceptually similar theoretical models. This shows that the FDCS are very sensitive to the details of the underlying few-body dynamics in this region. Data also indicated the limitations of perturbative methods and the need for non-perturbative approaches”--Abstract, page iv

Differential Study of Projectile Coherence Effects on Double Capture Processes in p + Ar Collisions

We have measured differential yields for double capture and double capture accompanied by ionization in 75 keV p + Ar collisions. Data were taken for two different transverse projectile coherence lengths. A small effect of the projectile coherence properties on the yields were found for double capture, but not for double capture plus ionization. The results suggest that multiple projectile-target interactions can lead to a significant weakening of projectile coherence effects

Effect of different nitrogen levels on yield and yield attributes of different rice varieties in DDSR condition at Kanchanpur, Nepal

An experiment on the effect of different nitrogen levels on yield and yield attributes of different rice varieties was conducted in Kanchanpur, Nepal, from March 2021 to July 2021. The experiment was laid in randomized complete block design with two factors: nitrogen levels and rice varieties, each factor having three levels (Nitrogen: 60kg/ha, 120kg/ha, and 180kg/ha and rice varieties: Hardinath 1, Hardianth 3 and Chaite 5) resulting in nine treatment combinations. Rice seeds were sown directly in experimental plots under the dry condition on March 24, 2021. The plant spacing was 20x20cm^2. Growth parameters, grain yield, and yield attributing traits of rice were recorded. The statistical results revealed significant differences between the treatments regarding agronomical parameters, yield attributing characters, and grain yield. The results indicated that the 180 kg/ha level of N application contributes to the higher plant height (74.502 cm), the number of tillers (1101.667), effective tillers (577.222), filled grain per panicle (116.490), panicle length (25.241 cm), grain yield (4.7 ton/ha) and straw yield (10.564 ton/ha). Among the varieties, Hardinath 3 produced significantly higher plant height (79.68 cm), panicle length (25.68cm), sterility percentage, and 1000 grain weight (24.60g) as compared to Hardinath 1 and Chapter 5, respectively. However, yield and yield attributing characters like grain yield, straw yield, effective tillers, and filled grains per panicle were significantly higher in Chaite 5. Therefore, a nitrogen level of 180 kg/ha and variety Chaite5 may be used for better productivity in Kanchanpur, Nepal

Concentration of Thiourea is effective in breaking the dormancy of potato (Solanum tuberosum L.) varieties

Potato germination is highly sensitive to ecological conditions. High altitude and low annual average temperature result in tuber dormancy and poor sprouting. Dormancy has become a significant constraint for lowering potato production, which hinders the possibility of growing two crop cycles per year. An experiment was conducted from February to April 2020. Two major potato varieties (Desiree and Cardinal) were treated with four Thiourea concentrations (0, 1, 2, and 3%) in a two factorial, completely randomized block design with three replications. Tubers were soaked for 2 hours in different Thiourea solution as per treatments, air dried until excess solution was removed and kept in a dark room on plastic trays. With the progress of experiment dormancy breaking and sprouting parameters like early sprouting, dormancy breaking, sprout length and sprout density were recorded. It was found that Thiourea has a significant effect on all observed attributes as per varieties of potato. For Desiree variety, Thiourea (1%) decreased dormancy period by 22 days compared to control (Desiree*Thiourea 0%) and produced the longest average sprout of 7.36cm at 49 days after treatment (DAT). On the other hand, for the Cardinal variety, Thiourea (3%) decreased tuber dormancy by 27 days compared to control (Cardinal*Thiourea 0%) and produced sprout of 7.75 cm at 49 DAT. In case of sprouts/tuber 1% and 3% Thiourea produced 4.13 and 1.91 sprouts/tubers in Desiree and Cardinal, respectively. The overall mean finding indicate that, 1% and 3% Thiourea concentration was significantly superior for breaking dormancy and enhancing sprouting of potato varieties of Desiree and Cardinal respectively

Interference Effects in Fully Differential Ionization Cross Sections near the Velocity Matching in P + He Collisions

We performed a fully differential experimental and theoretical study on ionization of He in intermediate-energy collisions with protons for a small projectile coherence length. Data were taken for an ejected electron energy corresponding to a speed close to the projectile speed (velocity matching). In the fully differential angular electron distributions, a pronounced double-peak structure, observed previously for a coherence length much larger than the atomic size, is much less pronounced in the current data. This observation is interpreted in terms of interference between first-and higher-order transition amplitudes. Although there is large quantitative disagreement between experiment and theory, the qualitative agreement supports this interpretation