Improved Background Model for the Large Area X-Ray Proportional Counter (LAXPC) Instrument on board AstroSat

We present an improved background model for the Large Area X-ray Proportional Counter (LAXPC) detectors on-board AstroSat. Because of large collecting area and high pressure, LAXPC instrument has a count rate, which varies during orbit. Apart from variation with latitude longitude orbit there is prominent quasi-diurnal not been modelled earlier. Using over 5 years observations, we determined period to be 84495 s using this period, it possible account also identify time intervals where fit good. These lead significant improvement in model. The can ascribed changes charged particle flux near Earth