Optical synthesizer for a large quadrant-array CCD camera: Center director's discretionary fund

The objective of this program was to design and develop an optical device, an optical synthesizer, that focuses four contiguous quadrants of a solar image on four spatially separated CCD arrays that are part of a unique CCD camera system. This camera and the optical synthesizer will be part of the new NASA-Marshall Experimental Vector Magnetograph, and instrument developed to measure the Sun's magnetic field as accurately as present technology allows. The tasks undertaken in the program are outlined and the final detailed optical design is presented

Good practice in assessment feedback in social studies: highlighting the significance of the student-teacher relationship

Assessment feedback has consistently emerged as an area of concern to students completing National Student Satisfaction Surveys (NSS). It is recognised as being an important element of the student learning experience and as such it remains a significant focus of enhancement activity. Using mixed research methods, the research reported in this article sought to identify student and academic staff perspectives as to what constitutes effective assessment feedback practice. The research was informed by subject level data from three English universities, with a particular focus on subjects related to social policy and social work. Whilst supportive of previous research reports (for example, Nicol and Macfarlane-Dick 2006, McDowell 2008, McDowell and Sambell 1999, Crook et al 2006), findings from this project particularly highlight the central significance to students of the quality of their relationships with staff. Indeed, other generic factors that are often argued to impact on assessment feedback, such as timeliness and consistency, appear to be contingent on the quality of staff-student relationships

Creative analysis of NSS data and collaborative research to inform good practice in assessment feedback

Funded by the Subject Centre for Social Policy and Social Work (SWAP), this research project sought to identify student and academic staff perspectives as to what constitutes effective assessment feedback practice. It was, in part, a subject level exploration in response to the fact that assessment feedback has consistently emerged as an area of concern to students completing National Student Satisfaction Surveys. Using mixed research methods, including drawing on data from the 2009 National Student Survey, the research was undertaken across SWAP constituency subject-areas in three universities. Whilst supportive of previous research reports (for example, Nicol & Macfarlane-Dick 2004, McDowell 2008, McDowell and Sambell 1999, Crook et al 2006), findings from this project particularly highlight the central significance to students of the quality of their relationships with staff. Indeed, other generic factors that are often argued to impact on assessment feedback such as timeliness and consistency appear to be contingent on the quality of staff-student relationships within specific departmental context

The MSFC vector magnetograph

The NASA/Marshall Space Flight Center's solar vector magnetograph system allows measurements of all components of the Sun's photospheric magnetic field over a 5 x 5 or 2.5 x 2.5 arc min square field of view with an optimum time resolution of approximately 100 sec and an optimum signal-to-noise of approximately 1000. The basic system components are described, including the optics, detector, digital system, and associated electronics. Automatic sequencing and control functions are outlined as well as manual selections of system parameters which afford unique system flexibility. Results of system calibration and performance are presented, including linearity, dynamic range, uniformity, spatial and spectral resolutions, signal-to-noise, electro-optical retardation and polarization calibration

Measurements of Solar Vector Magnetic Fields

Various aspects of the measurement of solar magnetic fields are presented. The four major subdivisions of the study are: (1) theoretical understanding of solar vector magnetic fields; (3) techniques for interpretation of observational data; and (4) techniques for data display

Nonpotential magnetic fields at sites of gamma ray flares

The relation between the degree of nonpotentiality of photospheric magnetic fields and the occurrence of gamma ray flares is examined. The parameter delta phi (magnetic shear) and the strength of the magnetic field intensity are used as measures of the degree of nonpotentiality, where delta phi is defined as the angular difference between the observed direction of the transverse component of the photospheric field and the direction of the potential field prescribed by the distribution of measured photospheric flux. An analysis of the great flare of April 24 to 25, 1984 is presented as an example of this technique to quantify the nonpotential characteristics of the pre-flare magnetic field. For this flare, which produced a large gamma ray event, strong shear and high field strengths prevailed over an extended length of the magnetic neutral line where the flare occurred. Moreover, the flare began near the area of strongest measured shear (89 to 90 deg). Four other flaring regions were analyzed; one of these produced a moderate gamma ray event while the other three did not produce detectable gamma rays. For all four regions the flares were located in the area where the field was not nonpotential, regardless of the class of flare. The fields of the gamma ray flares were compared with those associated with the flares without gamma rays, and little distinction was found in the degree of magnetic shear. The major difference is seen in the extent of the sheared field: for gamma ray events, the field is sheared over a longer length of the neutral line

Calculation of the profiles of the Stokes parameters and the degree of line polarization - An application of the solutions of Moe to the Unno transfer equations

Calculating profiles of Stokes parameters and degrees of linear and circular polarization using narrow band birefringent filte

Studies of solar magnetic fields during the solar maximum year

Observations and studies of solar magnetic fields that were carried out during the period of the solar maximum year (SMY) January 1980 to June 1981, are reviewed with the goal of providing a summary of what was learned about solar magnetic fields during the SMY. Such subjects as the relationship between solar magnetic fields and flares, the role of magnetic fields in the sunspot phenomenon, the magnetic-canopy structure overlying the supergranular network as well as the turbulent magnetic fields within the network, the fields within the polar crown prominences, and the solar magnetic cycle are addressed