Characteristic properties of Planacon MCP-PMTs

A systematic investigation of Planacon MCP-PMTs was performed using 64 XP85002/ FIT-Q photosensors. These devices are equipped with microchannel plates of reduced resistance. Results of a study of their gain stability over time and saturation level in terms of the average anode current are presented. This information allows one to determine the lower limit of the MCP resistance for stable Planacon operation. The spread of the electron multiplication characteristics for the entire production batch is also presented, indicating the remarkably low voltage requirements of these MCP-PMTs. Detection efficiency and noise characteristics, such as dark count rate and afterpulsing level, are also reviewed.Peer reviewe

Intramolecular vibrational dynamics of ν

Intramolecular dynamics of the vibrational levels (up to v = 5) of the ν1 mode in (CF3)2CCO molecule, induced via multiphoton selective excitation of this mode by resonant femtosecond IR radiation, was studied. The times of intramolecular vibrational energy redistribution (IVR) of each vibrational level v to the remaining modes of the molecule were measured. In accordance with the theory predictions the decrease of IVR time with increasing v is observed. A sharp reduction of the IVR time (up to 1 ps) at a wavelength of 2130 cm−1 of transition v=3 → v=4 was found. It was shown that with a negative chirp of a femtosecond radiation pulse the population of high-lying vibrational levels of ν1 modes significantly increases

Performance of the cost-effective Planacon ® MCP-PMTs in strong magnetic fields

We present the behavior of the cost-effective Planacon MCP-PMTs with pore diameter in the presence of axial magnetic fields up to 0.5 T. Having a batch of 62 devices of the same type, two MCP-PMTs were selected and their gain variation measured in different magnetic fields. These two otherwise identical devices satisfied the selection criteria by requiring the lowest (1.15 kV) and one of the highest (1.4 kV) bias voltage values to achieve a given gain. Both MCP-PMTs have a nearly identical tolerance of the strong magnetic field despite the significant difference in the bias voltage. This clarifies the mechanism of the B-field influence on the MCP-PMT gain, emphasizing the importance of the intrinsic parameters of the MCP emissive coating rather than external parameters, such as the total bias voltage. By evaluating the dependence of both gain and timing parameters on the magnetic field strength, we confirm the operability of such MCP-PMTs in strong magnetic fields in spite of the relatively large pore diameter and low bias voltage required for a given gain.peerReviewe

Intramolecular vibrational dynamics of ν1 mode in (CF3)2C=C=O molecule induced by resonant IR femtosecond radiation

Intramolecular dynamics of the vibrational levels (up to v = 5) of the ν1 mode in (CF3)2CCO molecule, induced via multiphoton selective excitation of this mode by resonant femtosecond IR radiation, was studied. The times of intramolecular vibrational energy redistribution (IVR) of each vibrational level v to the remaining modes of the molecule were measured. In accordance with the theory predictions the decrease of IVR time with increasing v is observed. A sharp reduction of the IVR time (up to 1 ps) at a wavelength of 2130 cm−1 of transition v=3 → v=4 was found. It was shown that with a negative chirp of a femtosecond radiation pulse the population of high-lying vibrational levels of ν1 modes significantly increases

Intramolecular vibrational dynamics of ν 1

Intramolecular dynamics of the vibrational levels (up to v = 5) of the ν1 mode in (CF3)2CCO molecule, induced via multiphoton selective excitation of this mode by resonant femtosecond IR radiation, was studied. The times of intramolecular vibrational energy redistribution (IVR) of each vibrational level v to the remaining modes of the molecule were measured. In accordance with the theory predictions the decrease of IVR time with increasing v is observed. A sharp reduction of the IVR time (up to 1 ps) at a wavelength of 2130 cm−1 of transition v=3 → v=4 was found. It was shown that with a negative chirp of a femtosecond radiation pulse the population of high-lying vibrational levels of ν1 modes significantly increases