This paper presents first results of an ongoing study of a possible association between muon enhancements at ground observed by the TUPI telescope and transient events such as the Sun ’ s X-ray activity .
The analysis of the observed phenomenon by using the GOES satellite archive data seems to indicate that on most cases the Ground Level Enhancements ( GLEs ) could potentially be associated with solar flares .
We show that small scale solar flares , those with prompt X-ray emission classified as C class ( power above 10 ^ { -6 } Watts m ^ { -2 } at 1 AU ) may give rise to GLEs , probably associated with solar protons and ions arriving to the Earth as a coherent particle pulse .
The TUPI telescope ’ s high performance with these energetic solar particles arises mainly from : ( 1 ) its high counting rate ( up to \sim 100 KHz ) .
This value in most cases is around 100 times higher than other detectors at ground and ( 2 ) due to its tracking system .
The telescope is always looking near the direction of the IMF lines .
The GLE ’ s delay in relation of the X-ray prompt emission suggest that shock driven by corona mass ejection ( CME ) is an essential requirement for the particle acceleration efficiency .