A temporary change in the tram line network means that from the city center ("Dam square") to reach NIKHEF (and vice versa), tram line 14 takes the same route as tram line 9 in the direction of Diemen. Therefore you can use either tram 9 or tram 14 to travel between NIKHEF (get off at the "Kruislaan" stop) and the Amsterdam city center. NIKHEF is not shown on the map shown below (NIKHEF is located about 4 cm to the right of where now tram lines 9,10 & 14 end on the map in the top-right corner).
Incidentally, for going from NIKHEF to the "Welcome Reception" at the Stopera (get off at the stop "Waterlooplein") and to the "Workshop Dinnner" in the d'Vijff Vlieghen (get off at the stop "Spui") you can now also use both tram lines 9 and 14. The reception and dinner locations are indicated on the map below.