Experimental results on the presence of thermal gradients on the surface of the aluminum primary mirror of a 620-mm balloon-borne Cassegrain telescope are presented. Balloon results were obtained on July 29, 1987 during the ARGO 87 experiment. A ray tracing program was develped to study the primary mirror enlightment, taking into account reflections and shadowing by the shield. It is suggested that a careful shield design is necessary for day-time operation, and that the line of sight must be kept at distances larger than 90 deg from the sun. Furthermore, night-time operation may be feasible at the level required by cosmic-background-radiation anisotropy measurements using a simple shield configuration.
A balloon borne millimetric telescope: experimental study of the thermal gradients on the primary mirror / DE BERNARDIS, Paolo; DE PETRIS, Marco; M., Epifani; M., Gervasi; G., Guarini; Masi, Silvia. - In: INFRARED PHYSICS. - ISSN 0020-0891. - STAMPA. - 28:(1988), pp. 243-248. [10.1016/0020-0891(88)90040-1]
A balloon borne millimetric telescope: experimental study of the thermal gradients on the primary mirror
DE BERNARDIS, Paolo;DE PETRIS, Marco;MASI, Silvia
1988
Abstract
Experimental results on the presence of thermal gradients on the surface of the aluminum primary mirror of a 620-mm balloon-borne Cassegrain telescope are presented. Balloon results were obtained on July 29, 1987 during the ARGO 87 experiment. A ray tracing program was develped to study the primary mirror enlightment, taking into account reflections and shadowing by the shield. It is suggested that a careful shield design is necessary for day-time operation, and that the line of sight must be kept at distances larger than 90 deg from the sun. Furthermore, night-time operation may be feasible at the level required by cosmic-background-radiation anisotropy measurements using a simple shield configuration.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
