Today I successfully detected beta particles using an MCP-PMT which we plan to use as a timing reference. Since an MCP-PMT is, as its name suggests, a device intended to detect photons and not electrons, I want briefly to summarize here my experience.
An MCP-PMT is a photon multiplying tube that differs with respect to conventional PMTs in that the multiplication is not performed in many plates at different voltages but instead it has a low number (1 or 2) so called “micro channel plates” (MCP) where the multiplication process takes place. Because of this, MCP-PMTs tend to have better time resolution because the electrons spread less in time. The following two cartoons may help to visualize this.
If we remove the photocathode in a PMT (as well as in an MCP-PMT) the device becomes an electron detection apparatus. Also, if there is a photocathode but beta particles can surpass it, the device can also be used as a beta detector. This is the use we are interested into. There are some references[1]A. Ronzhin, S. Los, E. Ramberg, M. Spiropulu, A. Apresyan, S. Xie, H. Kim, A. Zatserklyaniy, Development of a new fast shower maximum detector based on microchannel plates photomultipliers (MCP-PMT) … Continue reading[2]A. Bornheim, C. Pena, M. Spiropulu, S. Xie, Z. Zhang, Precision timing detectors with cadmium-telluride sensor, 21 September 2017, Nuclear Instruments and Methods in Physics Research Section A: … Continue reading[3]Test Beam Studies Of Silicon Timing for Use in Calorimetry, A. Apresyan, G. Bolla, A. Bornheim, H. Kim, S. Los, C. Pena, E. Ramberg,A. Ronzhin, M. Spiropulu, and S. Xie. … Continue reading[4]A. Ronzhin, M.G. Albrow, M. Demarteau, S. Los, S. Malik, A. Pronko, E. Ramberg, A. Zatserklyaniy, Development of a 10ps level time of flight system in the Fermilab Test Beam Facility, Nuclear … Continue reading that report the usage of “plain MCP-PMTs” to detect MIP particles, and report good timing characteristics. So we went for it, and we equipped our lab with one MCP-PMT of type PP2365AC by Photonis.
After a long waiting period of time, the device finally arrived to our lab and today I made it work with the beta source, as we want. To do so I had to cover the glass window with aluminum tape in order to get rid of any unwanted photon from the ambient, otherwise it does not work as expected. Below there is a short video I made in the lab.
Next step is to measure coincidences of betas between this MCP-PMT and DUTs, to characterize their time resolution.
References
| ↑1 | A. Ronzhin, S. Los, E. Ramberg, M. Spiropulu, A. Apresyan, S. Xie, H. Kim, A. Zatserklyaniy, Development of a new fast shower maximum detector based on microchannel plates photomultipliers (MCP-PMT) as an active element, 21 September 2014, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. https://doi.org/10.1016/j.nima.2014.05.039. |
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| ↑2 | A. Bornheim, C. Pena, M. Spiropulu, S. Xie, Z. Zhang, Precision timing detectors with cadmium-telluride sensor, 21 September 2017, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, https://doi.org/10.1016/j.nima.2017.04.024. |
| ↑3 | Test Beam Studies Of Silicon Timing for Use in Calorimetry, A. Apresyan, G. Bolla, A. Bornheim, H. Kim, S. Los, C. Pena, E. Ramberg,A. Ronzhin, M. Spiropulu, and S. Xie. https://inspirehep.net/files/f6b1cd929d10bb6fe53679fd2f38d3c7. |
| ↑4 | A. Ronzhin, M.G. Albrow, M. Demarteau, S. Los, S. Malik, A. Pronko, E. Ramberg, A. Zatserklyaniy, Development of a 10ps level time of flight system in the Fermilab Test Beam Facility, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, https://doi.org/10.1016/j.nima.2010.08.025. |