You can book a room at booking.com yourself. It has been our experience in the past that it's not much of a difference pricewise. Hotels that are often used by Nikhef: Hotel Parklane https://www.hotel-parklane.nl/ Hotel Rembrandt http://www.hotelrembrandt.nl/ Eden Lancaster Hotel https://www.thelancasterhotelamsterdam.com/en/ Bridge Hotel http://www.thebridgehotel.nl/ Eden Amsterdam Hotel https://www.edenhotelamsterdam.com/en/ Eden Manor Hotel https://www.themanorhotelamsterdam.com/en/ Hotel Casa https://hotelcasa.nl/ Motel One https://www.motel-one.com/en/hotels/amsterdam/hotel-amsterdam-waterlooplein/
The first five hotels are located along tram line 14, which you can take from Central Station. The tramline closest to Nikhef is tram 19, which you can take at the Alexanderplein stop (5-10 minute walk from most of the hotels). Eden Manor Hotel is closest to Nikhef, along tram 19. Hotel Casa is near Amstel Station. Motel One near Waterlooplein. Prices vary between 80-150 euro (depending on season and availability). There is also a good train connection between Amsterdam Central Station and Amsterdam Science Park.
