Sympathetic Cooling of Protons by Resonant Coupling to Laser Cooled Be ions

by Christian Smorra (Johannes Gutenberg Universitaet Mainz (DE))

Thursday 28 Oct 2021, 16:00 → 18:00 Europe/Zurich

Reaching the lowest possible temperature is essential in any precision spectroscopy experiment at the frontier of physics. The BASE collaboration started recently to explore sympathetic cooling methods for protons and antiprotons, since our magnetic moment measurements are limited by cooling of the cyclotron mode via resistive cooling. We present our implementation of cooling a single trapped proton using image currents to form a coupled oscillator system with separately trapped laser-cooled beryllium ions. The method is applicable to a broad range of trapped particles independent of the charge, and can be applied also to antiprotons, highly-charged or molecular ions. Recently, we succeeded in cooling the proton to 15% of the environment temperature using an LC circuit to enhance the coupling strength [1]. We further discuss the prospects of decreasing the temperature down to the 10 mK level in presence of the heating from the LC circuit and frequency uncertainties and drifts. A further decrease in temperature would greatly reduce the uncertainty of proton/antiproton magnetic moment measurements, and improve tests of CPT invariance in the baryon sector, and searches for dark matter particles, such as axions [2, 3] or millicharged particles [4].

[1] M. Bohman et al., Nature 596, pages 514–518 (2021).
[2] C. Smorra et al., Nature 575, pages 310–314 (2019).
[3] J. A. Devlin et al., Phys. Rev. Lett. 126, 041301 (2021).
[4] D. Budker et al., arXiv:2108.05283 [hep-ph] (2021).

To participate in this seminar, check this link

https://us04web.zoom.us/j/932734874

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In case of questions contact Stefan Ulmer (stefan.ulmer@cern.ch)

Reaching the lowest possible temperature is essential in any precision spectroscopy experiment at the frontier of physics. The BASE collaboration started recently to explore sympathetic cooling methods for protons and antiprotons, since our magnetic moment measurements are limited by cooling of the cyclotron mode via resistive cooling. We present our implementation of cooling a single trapped proton using image currents to form a coupled oscillator system with separately trapped laser-cooled beryllium ions. The method is applicable to a broad range of trapped particles independent of the charge, and can be applied also to antiprotons, highly-charged or molecular ions. Recently, we succeeded in cooling the proton to 15% of the environment temperature using an LC circuit to enhance the coupling strength [1]. We further discuss the prospects of decreasing the temperature down to the 10 mK level in presence of the heating from the LC circuit and frequency uncertainties and drifts. A further decrease in temperature would greatly reduce the uncertainty of proton/antiproton magnetic moment measurements, and improve tests of CPT invariance in the baryon sector, and searches for dark matter particles, such as axions [2, 3] or millicharged particles [4].

[1] M. Bohman et al., Nature 596, pages 514–518 (2021).
[2] C. Smorra et al., Nature 575, pages 310–314 (2019).
[3] J. A. Devlin et al., Phys. Rev. Lett. 126, 041301 (2021).
[4] D. Budker et al., arXiv:2108.05283 [hep-ph] (2021).

To participate in this seminar, check this link

https://us04web.zoom.us/j/932734874

---

In case of questions contact Stefan Ulmer (stefan.ulmer@cern.ch)

Reaching the lowest possible temperature is essential in any precision spectroscopy experiment at the frontier of physics. The BASE collaboration started recently to explore sympathetic cooling methods for protons and antiprotons, since our magnetic moment measurements are limited by cooling of the cyclotron mode via resistive cooling. We present our implementation of cooling a single trapped proton using image currents to form a coupled oscillator system with separately trapped laser-cooled beryllium ions. The method is applicable to a broad range of trapped particles independent of the charge, and can be applied also to antiprotons, highly-charged or molecular ions. Recently, we succeeded in cooling the proton to 15% of the environment temperature using an LC circuit to enhance the coupling strength [1]. We further discuss the prospects of decreasing the temperature down to the 10 mK level in presence of the heating from the LC circuit and frequency uncertainties and drifts. A further decrease in temperature would greatly reduce the uncertainty of proton/antiproton magnetic moment measurements, and improve tests of CPT invariance in the baryon sector, and searches for dark matter particles, such as axions [2, 3] or millicharged particles [4].

[1] M. Bohman et al., Nature 596, pages 514–518 (2021).
[2] C. Smorra et al., Nature 575, pages 310–314 (2019).
[3] J. A. Devlin et al., Phys. Rev. Lett. 126, 041301 (2021).
[4] D. Budker et al., arXiv:2108.05283 [hep-ph] (2021).

To participate in this seminar, check this link

https://us04web.zoom.us/j/932734874

---

Reaching the lowest possible temperature is essential in any precision spectroscopy experiment at the frontier of physics. The BASE collaboration started recently to explore sympathetic cooling methods for protons and antiprotons, since our magnetic moment measurements are limited by cooling of the cyclotron mode via resistive cooling. We present our implementation of cooling a single trapped proton using image currents to form a coupled oscillator system with separately trapped laser-cooled beryllium ions. The method is applicable to a broad range of trapped particles independent of the charge, and can be applied also to antiprotons, highly-charged or molecular ions. Recently, we succeeded in cooling the proton to 15% of the environment temperature using an LC circuit to enhance the coupling strength [1]. We further discuss the prospects of decreasing the temperature down to the 10 mK level in presence of the heating from the LC circuit and frequency uncertainties and drifts. A further decrease in temperature would greatly reduce the uncertainty of proton/antiproton magnetic moment measurements, and improve tests of CPT invariance in the baryon sector, and searches for dark matter particles, such as axions [2, 3] or millicharged particles [4].

[1] M. Bohman et al., Nature 596, pages 514–518 (2021).
[2] C. Smorra et al., Nature 575, pages 310–314 (2019).
[3] J. A. Devlin et al., Phys. Rev. Lett. 126, 041301 (2021).
[4] D. Budker et al., arXiv:2108.05283 [hep-ph] (2021).

To participate in this seminar, check this link

https://us04web.zoom.us/j/932734874

---

Reaching the lowest possible temperature is essential in any precision spectroscopy experiment at the frontier of physics. The BASE collaboration started recently to explore sympathetic cooling methods for protons and antiprotons, since our magnetic moment measurements are limited by cooling of the cyclotron mode via resistive cooling. We present our implementation of cooling a single trapped proton using image currents to form a coupled oscillator system with separately trapped laser-cooled beryllium ions. The method is applicable to a broad range of trapped particles independent of the charge, and can be applied also to antiprotons, highly-charged or molecular ions. Recently, we succeeded in cooling the proton to 15% of the environment temperature using an LC circuit to enhance the coupling strength [1]. We further discuss the prospects of decreasing the temperature down to the 10 mK level in presence of the heating from the LC circuit and frequency uncertainties and drifts. A further decrease in temperature would greatly reduce the uncertainty of proton/antiproton magnetic moment measurements, and improve tests of CPT invariance in the baryon sector, and searches for dark matter particles, such as axions [2, 3] or millicharged particles [4].

[1] M. Bohman et al., Nature 596, pages 514–518 (2021).
[2] C. Smorra et al., Nature 575, pages 310–314 (2019).
[3] J. A. Devlin et al., Phys. Rev. Lett. 126, 041301 (2021).
[4] D. Budker et al., arXiv:2108.05283 [hep-ph] (2021).

To participate in this seminar, check this link

https://us04web.zoom.us/j/932734874

---

Reaching the lowest possible temperature is essential in any precision spectroscopy experiment at the frontier of physics. The BASE collaboration started recently to explore sympathetic cooling methods for protons and antiprotons, since our magnetic moment measurements are limited by cooling of the cyclotron mode via resistive cooling. We present our implementation of cooling a single trapped proton using image currents to form a coupled oscillator system with separately trapped laser-cooled beryllium ions. The method is applicable to a broad range of trapped particles independent of the charge, and can be applied also to antiprotons, highly-charged or molecular ions. Recently, we succeeded in cooling the proton to 15% of the environment temperature using an LC circuit to enhance the coupling strength [1]. We further discuss the prospects of decreasing the temperature down to the 10 mK level in presence of the heating from the LC circuit and frequency uncertainties and drifts. A further decrease in temperature would greatly reduce the uncertainty of proton/antiproton magnetic moment measurements, and improve tests of CPT invariance in the baryon sector, and searches for dark matter particles, such as axions [2, 3] or millicharged particles [4].

[1] M. Bohman et al., Nature 596, pages 514–518 (2021).
[2] C. Smorra et al., Nature 575, pages 310–314 (2019).
[3] J. A. Devlin et al., Phys. Rev. Lett. 126, 041301 (2021).
[4] D. Budker et al., arXiv:2108.05283 [hep-ph] (2021).

To participate in this seminar, check this link

https://us04web.zoom.us/j/932734874

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