Investigation of single crystal ferrite thin film Semiannual report, 1 Feb. - 31 Jul. 1969

Vapor deposition of single crystal thin films of lithium ferrite utilizing ferric chlorid

Self-Criticism, Neediness, and Distress Among Women Undergoing Treatment for Breast Cancer: A Preliminary Test of the Moderating Role of Adjustment to Illness

A diagnosis of cancer can be extremely stressful, and for that reason, cancer patients’ adjustment has been widely studied. Little is known, however, about how patients’ personality vulnerabilities affect their adjustment to cancer. The present study examined the moderating role of several psychological strategies of adjustment to cancer in the associations between the personality predispositions of self-criticism and neediness and distress among women diagnosed with breast cancer. Portuguese women who had been diagnosed with breast cancer for the first time (n _ 50) completed the Depressive Experiences Questionnaire, the Hospital Anxiety and Depression Scale, and the Mini-Mental Adjustment to Cancer Scale questionnaires. Both self-criticism and neediness were found to be associated with increased levels of distress, with a stronger association observed for neediness. Hierarchical regressions indicated that more adaptive adjustment to cancer (i.e., low levels of helplessness/hopelessness, low levels of anxious preoccupation, high levels of fatalism, and high levels of fighting spirit) moderates the association between neediness and distress. There was no evidence that any of the adjustment variables had any mediating effect on the relationship between the personality variables (self-criticism and neediness) and distress. Results are discussed in the context of personality vulnerability and maladaptive psychological response to the disease as a stressful life event. Implications for treatment are discussed. Though promising, the results are preliminary and more research on larger samples is warranted

Solid state photomultiplier for astronomy, phase 2

Epitaxial layers with varying donor concentration profiles were grown on silicon substrate wafers using chemical vapor deposition (CVD) techniques, and solid state photomultiplier (SSPM) devices were fabricated from the wafers. Representative detectors were tested in a low background photon flux, low temperature environment to determine the device characteristics for comparison to NASA goals for astronomical applications. The SSPM temperatures varied between 6 and 11 K with background fluxes in the range from less than 5 x 10 to the 6th power to 10 to the 13th power photons/square cm per second at wavelengths of 3.2 and 20 cm. Measured parameters included quantum efficiency, dark count rate and bias current. Temperature for optimal performance is 10 K, the highest ever obtained for SSPMs. The devices exhibit a combination of the lowest dark current and highest quantum efficiency yet achieved. Experimental data were reduced, analyzed and used to generate recommendations for future studies. The background and present status of the microscopic theory of SSPM operation were reviewed and summarized. Present emphasis is on modeling of the avalanche process which is the basis for SSPM operation. Approaches to the solution of the Boltzmann transport equation are described and the treatment of electron scattering mechanisms is presented. The microscopic single-electron transport theory is ready to be implemented for large-scale computations

Development of a high capacity bubble domain memory element and related epitaxial garnet materials for application in spacecraft data recorders. Item 2: The optimization of material-device parameters for application in bubble domain memory elements for spacecraft data recorders

Bubble domain materials and devices are discussed. One of the materials development goals was a materials system suitable for operation of 16 micrometer period bubble domain devices at 150 kHz over the temperature range -10 C to +60 C. Several material compositions and hard bubble suppression techniques were characterized and the most promising candidates were evaluated in device structures. The technique of pulsed laser stroboscopic microscopy was used to characterize bubble dynamic properties and device performance at 150 kHz. Techniques for large area LPE film growth were developed as a separate task. Device studies included detector optimization, passive replicator design and test and on-chip bridge evaluation. As a technology demonstration an 8 chip memory cell was designed, tested and delivered. The memory elements used in the cell were 10 kilobit serial registers

Development of a high capacity bubble domain memory element and related epitaxial garnet materials for application in spacecraft data recorders. Item 1: Development of a high capacity memory element

Several versions of the 100K bit chip, which is configured as a single serial loop, were designed, fabricated and evaluated. Design and process modifications were introduced into each succeeding version to increase device performance and yield. At an intrinsic field rate of 150 KHz the final design operates from -10 C to +60 C with typical bias margins of 12 and 8 percent, respectively, for continuous operation. Asynchronous operation with first bit detection on start-up produces essentially the same margins over the temperature range. Cost projections made from fabrication yield runs on the 100K bit devices indicate that the memory element cost will be less than 10 millicents/bit in volume production

Investigation of single crystal ferrite thin films

Materials suitable for use in magnetic bubble domain memories were developed for aerospace applications. Practical techniques for the preparation of such materials in forms required for fabrication of computer memory devices were considered. The materials studied were epitaxial films of various compositions of the gallium-substituted yttrium gadolinium iron garnet system. The major emphasis was to determine their bubble properties and the conditions necessary for growing uncracked, high quality films