No. 149, The Alfven Speed above a Sunspot, and Gamma-rays by H. Hudson and L. Fletcher. Flare effects in sunspot umbrae...

http://sprg.ssl.berkeley.edu/~tohban/wiki/index.php/The_Alfven_Speed_above_a_Sunspot,_and_Gamma-rays

Older Nuggets are available at
http://sprg.ssl.berkeley.edu/~tohban/wiki/index.php/RHESSI_Science_Nuggets
 (the new series), and at
http://sprg.ssl.berkeley.edu/~tohban/nuggets/ (the original series).

We publish these at roughly two-week intervals and welcome
contributions, which should be at least loosely related to RHESSI
science.