OPTICAL-PUMPING OF METASTABLE (2P53S3PO) STATE OF NE-21

Metastable 2p**5 3s **3P//0 (1s//3 in Paschen notation) atoms of **2**1Ne are optically pumped in a weak discharge by means of a C. W. dye laser. The magnetic resonance is observed for a g-factor g(**3P//0) equals (3. 02 plus or minus 0. 30) multiplied by 10** minus **4 larger than the ground state g-factor g(**1S//0) equals 2. 40275 plus or minus 0. 000 05) multiplied by 10** minus **4 and in good agreement with the theory (3. 08 multiplied by 10** minus **4) taking into account the mixing of the **3P//0 with the **1P//1 and **3P//1 levels of the 2P**5 3s configuration through the hyperfine interaction. The precision of the result is poor because of a relatively short relaxation time of the orientation of the **3P//0 state in the present experimental conditions.