We present a newly constructed spectrometer for negative--ion/positive--ion coincidence spectroscopy of gaseous samples. The instrument consists of two time--of--flight ion spectrometers and a magnetic momentum filter for deflection of electrons. The instrument can measure double and triple coincidences between mass--resolved negative and positive ions with high detection efficiency. First results include identification of several negative--ion/positive--ion coincidence channels following inner-shell photoexcitation of sulfur hexaflouride (SF$_6$).
- Accelerator Physics and Instrumentation
- Atom and Molecular Physics and Optics
- Negative--ion/positive--ion coincidence spectroscopy
- time--of--flight mass spectroscopy
- synchrotron radiation