TY - JOUR
KW - "Phosphor
KW - Micro-channel plate
KW - Imaging"
AU - Yuval Shagam
AU - William Cairncross
AU - Tanya Roussy
AU - Yan Zhou
AU - Kia Ng
AU - Daniel Gresh
AU - Tanner Grogan
AU - Jun Ye
AU - Eric Cornell
AB - Imaging micro-channel plate (MCP) detectors are a common tool for chemical physics studies used to image a single ion mass species in a time-of-flight (TOF) spectrum. Temporal selection of the mass to be imaged is traditionally implemented by gating the voltage across the MCP stack, however this leads to the loss of all information about other species in the mass spectrum. Here we show that by gating the phosphor voltage instead, as has been demonstrated by Zajfman et al. (1995) among others, we gain the capability of measuring multiple masses in TOF while retaining the ability to image a single desired species. In our precision spectroscopy experiment, we image the spatial distribution of Hf+ photodissociation fragments, while its more plentiful HfF+ precursor, which arrives at a later time, can also be detected in TOF. This enables the shot by shot normalization of technical noise associated with the precursor production. Since the scheme alters only the configuration of the high-voltage switch, it can be readily implemented in most existing gated MCP setups, allowing the full TOF information to be harvested. Combining the imaging and TOF data in a single shot, we can detect species with substantially different abundances.
BT - Journal of Molecular Spectroscopy
DA - 2020-02
DO - 10.1016/j.jms.2020.111257
N2 - Imaging micro-channel plate (MCP) detectors are a common tool for chemical physics studies used to image a single ion mass species in a time-of-flight (TOF) spectrum. Temporal selection of the mass to be imaged is traditionally implemented by gating the voltage across the MCP stack, however this leads to the loss of all information about other species in the mass spectrum. Here we show that by gating the phosphor voltage instead, as has been demonstrated by Zajfman et al. (1995) among others, we gain the capability of measuring multiple masses in TOF while retaining the ability to image a single desired species. In our precision spectroscopy experiment, we image the spatial distribution of Hf+ photodissociation fragments, while its more plentiful HfF+ precursor, which arrives at a later time, can also be detected in TOF. This enables the shot by shot normalization of technical noise associated with the precursor production. Since the scheme alters only the configuration of the high-voltage switch, it can be readily implemented in most existing gated MCP setups, allowing the full TOF information to be harvested. Combining the imaging and TOF data in a single shot, we can detect species with substantially different abundances.
PY - 2020
SE - 111257
EP - 111257
T2 - Journal of Molecular Spectroscopy
TI - Continuous temporal ion detection combined with time-gated imaging: Normalization over a large dynamic range
UR - http://www.sciencedirect.com/science/article/pii/S0022285220300254
VL - 368
SN - 0022-2852
ER -