Cluster production in the matrix assembly cluster source

• Main Author: Terry, William David
• Published: University of Birmingham 2017
• Subjects: 539.7; QC Physics
• Online Access: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.725413

This thesis focuses on the development of the Matrix Assembly Cluster Source (MACS). Firstly, a transmission mode MACS instrument has been upgraded and integrated with a Time-Of-Flight mass filter. An equivalent cluster beam current of 100 nA of silver nanoclusters has been achieved (previously several nA). Furthermore, an intrinsic size control has been demonstrated in the 1-5 nm range by varying the silver concentration in the matrix. The MACS has been demonstrated in a reflection regime, reaching a ~1% conversion of incident ions to clusters (~0.03% in transmission). The effect of the beam-plate geometry has been investigated and a new reflection mode system commissioned, producing a maximum equivalent silver cluster current of 170±16 nA. An average equivalent current of 40 nA has been deposited for 45 minutes. Nanocluster arrays have been demonstrated to preferentially immobilize dye molecules, the primary step towards label-free cluster-based biochips. Finally, visible range ion-induced light emission from the matrix was studied. Optical measurements demonstrate significant change in the ion-induced light emission spectra with the addition of O2, N2, or Ag to the matrix. By careful analysis of the emission spectra, the thickness, composition, and in certain cases, molecular composition of the matrix can be accessed.