Introduction

On December 4 and 5, 2000, we will have a two-day workshop on the detection of the solar neutrinos below 1 MeV. The workshop will be held at Sanjyo-hall in the University of Tokyo, Tokyo, Japan. The purpose of this workshop is to discuss all aspects of low energy solar neutrino experiments, including problems and techniques.

 The previous and currently running solar neutrino experiments observed deficit of solar neutrino flux and they strongly suggest neutrino oscillations. Low energy solar neutrinos are measured only by radiochemical experiments so far and we know only the integral flux of those neutrinos. The energy spectrum of solar neutrinos was measured only for 8B neutrinos up to now and the spectrum measurement below 1MeV should supply important information. pp and 7Be neutrinos are main source of low energy solar neutrinos and more than 97% of total solar neutrino flux is predicted to lie below 1 MeV. The flux and spectrum of pp neutrinos are predicted precisely by the standard solar model. The energy spectrum and time dependence of the survival probabilites of those neutrinos should provide crucial information on neutrino oscillations. In order to make detectors for the low energy solar neutrinos, new techniques must be devised to reduce radioactive backgrounds and identify solar neutrino signals. The development of the techniques requires world wide cooperation of researchers interested in neutrino physics and in neutrino astrophysics.