Driver Accelerator Design for the 10 kW Upgrade of the Jefferson Lab IR FEL

An upgrade of the Jefferson Lab IR FEL is now under construction. It will provide 10 kW output light power in a wavelength range of 2-10 microns. The FEL will be driven by a modest-sized 80-210 MeV, 10 mA energy-recovering superconducting RF (SRF) linac. Stringent phase space requirements at the wiggler, low beam energy, and high beam current subject the design to numerous constraints. These are imposed by the need for both transverse and longitudinal phase space management, the potential impact of collective phenomena (space charge, wakefields, beam break-up (BBU), and coherent synchrotron radiation (CSR)), and interactions between the FEL and the accelerator RF system. This report addresses these issues and presents an accelerator design solution meeting the requirements imposed by physical phenomena and operational necessities.Comment: submission THC03 for LINAC200

The role of Volatile Anesthetics in Cardioprotection: a systematic review.

This review evaluates the mechanism of volatile anesthetics as cardioprotective agents in both clinical and laboratory research and furthermore assesses possible cardiac side effects upon usage. Cardiac as well as non-cardiac surgery may evoke perioperative adverse events including: ischemia, diverse arrhythmias and reperfusion injury. As volatile anesthetics have cardiovascular effects that can lead to hypotension, clinicians may choose to administer alternative anesthetics to patients with coronary artery disease, particularly if the patient has severe preoperative ischemia or cardiovascular instability. Increasing preclinical evidence demonstrated that administration of inhaled anesthetics - before and during surgery - reduces the degree of ischemia and reperfusion injury to the heart. Recently, this preclinical data has been implemented clinically, and beneficial effects have been found in some studies of patients undergoing coronary artery bypass graft surgery. Administration of volatile anesthetic gases was protective for patients undergoing cardiac surgery through manipulation of the potassium ATP (KATP) channel, mitochondrial permeability transition pore (mPTP), reactive oxygen species (ROS) production, as well as through cytoprotective Akt and extracellular-signal kinases (ERK) pathways. However, as not all studies have demonstrated improved outcomes, the risks for undesirable hemodynamic effects must be weighed against the possible benefits of using volatile anesthetics as a means to provide cardiac protection in patients with coronary artery disease who are undergoing surgery

Modeling a Nb\u3csub\u3e3\u3c/sub\u3eSn Cryounit in GPT at UITF

Nb3Sn is a prospective material for future superconducting radio frequency (SRF) accelerator cavities. Compared to conventional niobium, the material can achieve higher quality factors, higher temperature operation, and potentially higher accelerating gradients (Eacc ≈ 96 MV/m). In this work, we performed modeling of the Upgraded Injector Test Facility (UITF) at Jefferson Lab utilizing newly constructed Nb3Sn cavities. We studied the effects of the buncher cavity and varied the gun voltage from 200-500 keV. We have calibrated and optimized the SRF cavity gradients and phases for the Nb3Sn five-cell cavities\u27 energy gains with the framework of the General Particle Tracer (GPT). Our calculations show the beam goes cleanly through the unit. There is full energy gain out of the second SRF cavity but not from the first SRF cavity due to non-relativistic phase shifts

Effects of Cognitive Restructuring and Defusion for Coping with Difficult Thoughts in a Predominantly White Female College Student Sample

Background: Understanding how cognitive processes are naturally used by untrained individuals in the moment to cope with difficult thoughts may help inform effective and efficient interventions. Methods: This study investigated self-reported naturalistic use of two evidence-based processes, cognitive restructuring and cognitive defusion, in an untrained, predominantly White female college student sample (n = 194) through ecological momentary assessments over seven days. Results: Cognitive restructuring and defusion had a large positive relationship. Both processes were also positively associated with increased momentary use of suppression and distraction. Only momentary defusion was associated with decreased rumination and negative affect at the same timepoint, while both defusion and restructuring were associated with positive affect and increased values progress at the same timepoint. Momentary defusion predicted later values progress, but only among those with low distress. Conclusions: Overall, results suggest that both cognitive restructuring and cognitive defusion are used in a nonclinical, untrained population, that both processes are overall beneficial when used in the moment, and that defusion may be particularly relevant to certain aims such as lower rumination or values progress across time points. Replication among clinical and more diverse populations is needed

Narrow-Band Emission in Thomson Sources Operating in the High-Field Regime

We present a novel and quite general analysis of the interaction of a high-field chirped laser pulse and a relativistic electron, in which exquisite control of the spectral brilliance of the up-shifted Thomson-scattered photon is shown to be possible. Normally, when Thomson scattering occurs at high field strengths, there is ponderomotive line broadening in the scattered radiation. This effect makes the bandwidth too large for some applications and reduces the spectral brilliance. We show that such broadening can be corrected and eliminated by suitable frequency modulation of the incident laser pulse. Furthermore, we suggest a practical realization of this compensation idea in terms of a chirped-beam-driven free electron laser oscillator configuration and show that significant compensation can occur, even with the imperfect matching to be expected in these conditions

Evaluation des Nationalen Programms Ernährung und Bewegung 2008–2012 [Evaluation NPEB 2008-2012]

Le PNAAP 2008–2012 définit la stratégie nationale pour la promotion d’une alimentation équilibrée et d'une activité physique suffisante. Le 18 juin 2008, le Conseil fédéral adoptait le programme et chargeait le DFI de sa mise en pratique. Ce programme définit des objectifs à long terme ainsi que des champs d’action prioritaires pour la marche à suivre au plan national ; c’est aussi sur ce programme que se base la collaboration des différents acteurs impliqués. Sa mise en œuvre a été confiée à l’Office fédéral de la santé publique (OFSP), en collaboration avec l’Office fédéral du sport (OFSPO) et en coordination avec les cantons et Promotion Santé Suisse (PSS). Le PNAAP a une vision: motiver la population et plus particulièrement les jeunes à se nourrir de manière équilibrée et à bouger suffisamment, car ces mesures sont à même de lutter efficacement contre la surcharge pondérale, l’obésité, les troubles du comportement alimentaire et les maladies non transmissibles qui y sont liées. Le programme a cinq objectifs: 1. Assurer la coordination nationale 2. Promouvoir une alimentation équilibrée 3. Promouvoir l’activité physique et le sport 4. Réaliser des modèles intégrés de promotion d’un poids corporel sain 5. Optimiser le conseil et la thérapi

Testing the applicability of idionomic statistics in longitudinal studies : The example of ‘doing what matters’

This study evaluated idionomic methods for identifying within-person links between therapeutically relevant processes and outcomes, using an ecological momentary assessment dataset of valued action and hedonic well-being (participants (n) = 425; 71.76% female; age = M(SD) = 22.20 (6.85); sampling design: 3–4 prompts per day; total measurements (n) = 6456). We compared the idionomic approach, integrating idiographic and nomothetic insights, with traditional multilevel modeling (MLM). Our methods included idiographic autoregressive integrative moving average models with an exogenous variable (i-ARIMAX), multivariate random-effects meta-analysis (RE-MA), deep Gaussian mixture modeling (DGMM), and multilevel vector autoregression modeling (Multilevel-VAR). The results showed that i-ARIMAX outperformed MLM in capturing within-person heterogeneity in the links between valued action and affect variables. Increases in values-based living were positively related to hedonic well-being but this effect showed a high degree of heterogeneity. A sub-group was identified, which we labeled the ‘Stoics,’ whose daily engagement in valued actions did not produce higher hedonic well-being (e.g., lower sadness or higher joy). Multilevel-VAR further revealed that for Stoics, stressful situations were linked to valued action, but not hedonic well-being. For Non-Stoics, valued action was less likely in stressful situations, but when valued action did occur it was associated with more joy and less sadness. The study offers initial evidence suggesting the superiority of an idionomic approach over a purely nomothetic one in capturing diverse pathways to clinically relevant outcomes. Idionomic methods may be useful or even necessary in personalizing psychological interventions, and thus may need to be considered by researchers and practitioners alike

IMPEDANCE BUDGET FOR CRAB CAVITY IN MEIC ELECTRON RING

The Medium Energy Electron-Ion Collider (MEIC) at Jefferson Lab has been envisioned as a first stage high energy particle accelerator beyond the 12 GeV upgrade of CEBAF. The estimate of impedance budget is important from the view point of beam stability and matching with other accelerator components driving currents. The detailed study of impedance budget for electron ring has been performed by considering the current design parameters of the e-ring. A comprehensive picture of the calculations involved in this study has been illustrated in the paper

Imaging and controlling electron transport inside a quantum ring

Traditionally, the understanding of quantum transport, coherent and ballistic1, relies on the measurement of macroscopic properties such as the conductance. While powerful when coupled to statistical theories, this approach cannot provide a detailed image of "how electrons behave down there". Ideally, understanding transport at the nanoscale would require tracking each electron inside the nano-device. Significant progress towards this goal was obtained by combining Scanning Probe Microscopy (SPM) with transport measurements2-7. Some studies even showed signatures of quantum transport in the surrounding of nanostructures4-6. Here, SPM is used to probe electron propagation inside an open quantum ring exhibiting the archetype of electron wave interference phenomena: the Aharonov-Bohm effect8. Conductance maps recorded while scanning the biased tip of a cryogenic atomic force microscope above the quantum ring show that the propagation of electrons, both coherent and ballistic, can be investigated in situ, and even be controlled by tuning the tip potential.Comment: 11 text pages + 3 figure