ar X iv : a st ro - p h / 97 04 00 7 v 1 1 A pr 1 99 7 A Broad Band and Large Area X - Ray Omni Sky Monitor ( BLOSM ) 1

We present a conceptual design for a new X-ray all sky monitor (ASM). Compared with previous ASMs, its salient features are: (1) it has a focusing capability that increases the signal to background ratio by a factor of 3; (2) it has a broad-band width: 200 eV to 15 keV; (3) it has a large X-ray collection area: ∼ 10 cm; (4) it has a duty cycle of nearly 100%, and (5) it can measure the position of a new source with an accuracy of a few minutes of arc. These features combined open up an opportunity for discovering new phenomena as well as monitoring existing phenomena with unprecedented coverage and sensitivity. Subject headings: Instrumentation: X-ray optics, all sky monitor 1 Contributed paper to “All-Sky X-Ray Observations in the Next Decade: A Workshop for ASM and GRB Missions in the X-Ray Band, The Institute of Physical and Chemical Research (RIKEN), Wako, Saitama, Japan, March 3-5, 1997.