Can small details bring big success? Construal levels as academic goal strategies

One avenue to help students reach educational goals is implementation intentions, a tool encouraging planning the “when, where, and how” of goal-oriented actions (Gollwitzer, 1999). However, implementation intentions need validating outside of the laboratory (Gollwitzer & Sheeran, 2006). To help do so, they can be viewed through Construal-Level Theory (CLT), which explains why we may have trouble setting intentions before we can fulfill them (Trope & Liberman 2010). A study was conducted wherein 56 participants from a section of PSYC 330 either wrote about their college study habits or completed implementation intentions preparing them to study for an upcoming exam. As they wrote, participants also completed measures of construal-levels. It was hypothesized that implementation intentions would immediately reduce construal levels and, over the following week, increase time students studied for their exam and the score they received. None of these hypotheses were supported; implementation intentions had no effect on study habits, exam scores, or construal levels. Results and their implications are discussed

Geometry Effects on Multipole Components and Beam Optics in High-Velocity Multi-Spoke Cavities

Velocity-of-light, multi-spoke cavities are being proposed to accelerate electrons in a compact light-source [1]. There are strict requirements on the beam quality which require that the linac have only small non-uniformities in the accelerating field. Beam dynamics simulations have uncovered varying levels of focusing and defocusing in the proposed cavities, which is dependent on the geometry of the spoke in the vicinity of the beam path. Here we present results for the influence different spoke geometries have on the multipole components of the accelerating field and how these components, in turn, impact the simulated beam properties

High Average Brilliance Compact Inverse Compton Light Source

There exists an increasing demand for compact Inverse Compton Light Sources (ICLS) capable of producing substantial fluxes of narrow-band X-rays. While multiple design proposals have been made, compared to typical bremsstrahlung sources, most of these have comparable fluxes and improve on the brilliance within a 0.1% bandwidth by only a few orders of magnitude. By applying cw superconducting rf beam acceleration and rf focusing to produce a beam of small emittance and magnetic focusing to produce a small spot size on the order of a few microns at collision, the source presented here provides a 12 keV X-ray beam which outperforms other compact designs and bremsstrahlung sources. Compared to a bremsstrahlung source, the flux is improved by at least an order of magnitude and the average brilliance by six orders of magnitude. Surpassing other compact ICLS designs, the source presented here is attractive to a wide variety of potential users

Compact SRF Linac for High Brilliance Inverse Compton Scattering Light Source

New designs for compact SRF linacs can produce micron-size electron beams. These can can be used for inverse Compton scattering light sources of exceptional flux and brilliance

High-Brilliance, High-Flux Compact Inverse Compton Light Source

The Old Dominion University Compact Light Source (ODU CLS) design concept is presented-a compact Inverse Compton Light Source (ICLS) with flux and brilliance orders of magnitude beyond conventional laboratory-scale sources and greater than other compact ICLS designs. This concept utilizes the physics of inverse Compton scattering of an extremely low emittance electron beam by a laser pulse of rms length of approximately two-thirds of a picosecond (2/3 ps). The accelerator is composed of a superconducting radio frequency (SRF) reentrant gun followed by four double-spoke SRF cavities. After the linac are three quadrupole magnets to focus the electron beam to the interaction point (IP). The distance from cathode surface to 1P is less than 6 m, with the cathode producing electron bunches with a bunch charge of 10 pC and a few picoseconds in length. The incident laser has 1 MW circulating power, a 1 micron wavelength, and a spot size of 3.2 microns at the IP. The repetition rate of this source is 100 MHz, in order to achieve a high flux despite the low bunch charge. The anticipated x-ray source parameters include an energy of 12 keV, with a total flux of 2.2 x 10(13) ph/s, the flux into a 0.1% bandwidth of 3.3 x 10(10) ph/(s0.1%BW), and the average brilliance of 3.4 x 10(14) ph/ (s mm(2 )mrad(2) 0.1%BW)

Beam Dynamics Studies of 499 Mhz Superconducting RF-Dipole Deflecting Cavity System

A 499 MHz deflecting cavity has been designed as a three-way beam spreader to separate an electron beam into 3 beams. The rf tests carried out on the superconducting rf-dipole cavity have demonstrated that a transverse voltage of 4.2 MV can be achieved with a single cavity. This paper discusses the beam dynamics on a deflecting structure operating in continuous-wave mode with a relativistic beam. The study includes the analysis on emittance growth, energy spread, and change in bunch size including effects due to field non-uniformities

Progress on a Compact Accelerator Design for a Compton Light Source

A compact Compton light source using an electron linear accelerator is in design at the Center for Accelerator Science at Old Dominion University and Jefferson Lab. We report on the current design, including beam properties through the entire system based on a full end-to-end simulation, compare current specifications to design goals, and target areas for improvement

Laser Pulsing in Linear Compton Scattering

Previous work on calculating energy spectra from Compton scattering events has either neglected considering the pulsed structure of the incident laser beam, or has calculated these effects in an approximate way subject to criticism. In this paper, this problem has been reconsidered within a linear plane wave model for the incident laser beam. By performing the proper Lorentz transformation of the Klein-Nishina scattering cross section, a spectrum calculation can be created which allows the electron beam energy spread and emittance effects on the spectrum to be accurately calculated, essentially by summing over the emission of each individual electron. Such an approach has the obvious advantage that it is easily integrated with a particle distribution generated by particle tracking, allowing precise calculations of spectra for realistic particle distributions in collision. The method is used to predict the energy spectrum of radiation passing through an aperture for the proposed Old Dominion University inverse Compton source. Many of the results allow easy scaling estimates to be made of the expected spectrum

VPLanet: The Virtual Planet Simulator

We describe a software package called VPLanet that simulates fundamental aspects of planetary system evolution over Gyr timescales, with a focus on investigating habitable worlds. In this initial release, eleven physics modules are included that model internal, atmospheric, rotational, orbital, stellar, and galactic processes. Many of these modules can be coupled simultaneously to simulate the evolution of terrestrial planets, gaseous planets, and stars. The code is validated by reproducing a selection of observations and past results. VPLanet is written in C and designed so that the user can choose the physics modules to apply to an individual object at runtime without recompiling, i.e., a single executable can simulate the diverse phenomena that are relevant to a wide range of planetary and stellar systems. This feature is enabled by matrices and vectors of function pointers that are dynamically allocated and populated based on user input. The speed and modularity of VPLanet enables large parameter sweeps and the versatility to add/remove physical phenomena to assess their importance. VPLanet is publicly available from a repository that contains extensive documentation, numerous examples, Python scripts for plotting and data management, and infrastructure for community input and future development.Comment: 75 pages, 34 figures, 10 tables, accepted to the Proceedings of the Astronomical Society of the Pacific. Source code, documentation, and examples available at https://github.com/VirtualPlanetaryLaboratory/vplane