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Estimating the sensitivity of the IceCube Upgrade to probe the interior of the Earth using atmospheric neutrino oscillations
Authors:
The IceCube Collaboration,
R. Abbasi,
M. Ackermann,
J. Adams,
S. K. Agarwalla,
J. A. Aguilar,
M. Ahlers,
J. M. Alameddine,
S. Ali,
N. M. Amin,
K. Andeen,
C. Arg{ü}elles,
S. Athanasiadou,
S. N. Axani,
R. Babu,
X. Bai,
A. Balagopal V.,
S. W. Barwick,
V. Basu,
R. Bay,
J. J. Beatty,
J. Becker Tjus,
P. Behrens,
J. Beise,
C. Bellenghi
, et al. (399 additional authors not shown)
Abstract:
The IceCube Upgrade is a densely instrumented central region of the IceCube Neutrino Observatory, deployed during the 2025-26 polar season. It will reduce the detector's energy threshold and improve overall reconstruction capabilities for multi-GeV atmospheric neutrinos, which in turn enhance their sensitivity to Earth matter effects as they traverse through the deep Earth. In this study, we descr…
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The IceCube Upgrade is a densely instrumented central region of the IceCube Neutrino Observatory, deployed during the 2025-26 polar season. It will reduce the detector's energy threshold and improve overall reconstruction capabilities for multi-GeV atmospheric neutrinos, which in turn enhance their sensitivity to Earth matter effects as they traverse through the deep Earth. In this study, we describe the potential of the IceCube Upgrade to observe Earth matter effects on atmospheric neutrinos and estimate the detector's sensitivity to probe key features of the Preliminary Reference Earth Model by utilizing these observations. We highlight the IceCube Upgrade's capability to estimate the mass of the Earth and verify the non-homogeneous distribution of matter density within the Earth. We also estimate the IceCube Upgrade sensitivity to measure the correlated densities of the Earth layers while incorporating constraints from the mass and moment of inertia of the Earth. Neutrino-based results would be independent and complementary to the seismic and gravitational measurements.
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Submitted 6 August, 2026;
originally announced August 2026.
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From Understanding to Resonance: A Case Study of Quantum Music and Embodied Science Communication
Authors:
Kenji Noda,
Akira Koga,
Stefan Heusler,
Koji Hashimoto
Abstract:
One challenge in science communication is how to engage audiences with highly abstract scientific fields often perceived as distant, technical, or inaccessible. This Practice Insight examines two initiatives implemented during the International Year of Quantum Science and Technology: Quantum Fest in Japan and Quantum100 in Germany, which together attracted more than 4000 participants. Both employe…
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One challenge in science communication is how to engage audiences with highly abstract scientific fields often perceived as distant, technical, or inaccessible. This Practice Insight examines two initiatives implemented during the International Year of Quantum Science and Technology: Quantum Fest in Japan and Quantum100 in Germany, which together attracted more than 4000 participants. Both employed immersive artistic experiences, including music, visual art, and embodied participation to create alternative entry points into quantum physics. Drawing on post-event surveys, participant comments, and stakeholder interviews, this paper identifies three dimensions of resonance: sensory immersion and reduced psychological barriers, collective embodied meaning-making, and emerging transformative engagement. The findings suggest that resonance-driven approaches can complement explanation-centred science communication by enabling audiences to form meaningful relationships with science before, alongside, or beyond conceptual understanding.
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Submitted 4 August, 2026;
originally announced August 2026.
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High-Energy Neutrino Tomography of the Earth's Interior with IceCube
Authors:
The IceCube Collaboration,
R. Abbasi,
M. Ackermann,
J. Adams,
J. A. Aguilar,
M. Ahlers,
J. M. Alameddine,
S. Ali,
N. M. Amin,
K. Andeen,
C. Argüelles,
S. Athanasiadou,
S. N. Axani,
R. Babu,
X. Bai,
A. Balagopal V.,
S. W. Barwick,
V. Basu,
R. Bay,
J. J. Beatty,
J. Becker Tjus,
P. Behrens,
J. Beise,
C. Bellenghi,
S. Benkel
, et al. (395 additional authors not shown)
Abstract:
The Earth's interior reflects its geological evolution, from accretion to present-day dynamics. Its structure drives the geodynamo in the outer core, generating the magnetic field that shields the surface from charged cosmic radiation. The primary observables of the Earth's interior are its radial density distribution and derived quantities such as its mass and moment of inertia. These have tradit…
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The Earth's interior reflects its geological evolution, from accretion to present-day dynamics. Its structure drives the geodynamo in the outer core, generating the magnetic field that shields the surface from charged cosmic radiation. The primary observables of the Earth's interior are its radial density distribution and derived quantities such as its mass and moment of inertia. These have traditionally been inferred from gravity and seismic wave propagation, which probe the macroscopic response of matter to gravitational and elastic forces. Here we instead constrain the Earth's density profile using high-energy neutrinos observed by the IceCube Neutrino Observatory at the South Pole. We analyze 10.7 years of predominantly muon-neutrino data spanning 500 GeV--100 TeV, including atmospheric neutrinos produced by cosmic-ray interactions in the Earth's atmosphere and the diffuse astrophysical neutrino flux. Neutrino attenuation depends on both the traversed column density and neutrino energy. By measuring the zenith- and energy-dependent flux suppression, we infer the Earth's radial density profile by fitting a concentric uniform-density shell model that incorporates neutrino fluxes, interaction cross sections, detector response, and glacial-ice systematic uncertainties. From the resulting density posteriors, we derive the Earth's mass and polar moment of inertia as measured by neutrinos. These are the most precise weak-interaction measurements of these quantities to date and are consistent with the Preliminary Reference Earth Model and independent gravitational determinations. Our results demonstrate that neutrinos provide a novel probe of planetary interiors via a distinct physical interaction, complementing gravity and seismology. With improved detectors and precision, neutrinos will further contribute to a multifaceted understanding of the Earth's structure.
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Submitted 7 July, 2026; v1 submitted 2 July, 2026;
originally announced July 2026.
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WavePID: Low-energy flavor identification using single-PMT time series in IceCube
Authors:
The IceCube Collaboration,
R. Abbasi,
M. Ackermann,
J. Adams,
J. A. Aguilar,
M. Ahlers,
J. M. Alameddine,
S. Ali,
N. M. Amin,
K. Andeen,
C. Argüelles,
S. Athanasiadou,
S. N. Axani,
R. Babu,
X. Bai,
A. Balagopal V.,
S. W. Barwick,
V. Basu,
R. Bay,
J. J. Beatty,
J. Becker Tjus,
P. Behrens,
J. Beise,
C. Bellenghi,
S. Benkel
, et al. (395 additional authors not shown)
Abstract:
The IceCube Neutrino Observatory, a cubic-kilometer detector at the South Pole, identifies neutrino flavor through event morphology. Sparse photon detection makes this classification particularly challenging in the 5--100~GeV regime, the energy range relevant for oscillation measurements and searches for physics beyond the Standard Model. We introduce WavePID, a template-based log-likelihood-ratio…
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The IceCube Neutrino Observatory, a cubic-kilometer detector at the South Pole, identifies neutrino flavor through event morphology. Sparse photon detection makes this classification particularly challenging in the 5--100~GeV regime, the energy range relevant for oscillation measurements and searches for physics beyond the Standard Model. We introduce WavePID, a template-based log-likelihood-ratio classifier that exploits nanosecond-scale timing on individual detector modules through three observables: the distance to the reconstructed vertex, the early-charge fraction, and the module-to-module time difference. Evaluated on a cascade-enriched sample selected by a state-of-the-art graph neural network, WavePID improves both cascade purity and classification performance over the neural network alone. This demonstrates that per-module pulse timing carries flavor-identification information complementary to morphology-based classifiers, opening a new physics-motivated observable for low-energy neutrino reconstruction. Geant4 simulations associate this signal with differences in Cherenkov emission geometry between muon tracks and electromagnetic showers. These results motivate exploiting nanosecond-scale pulse timing in future low-energy classifiers and in detector designs with improved per-module timing in next-generation neutrino telescopes.
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Submitted 20 August, 2026; v1 submitted 2 July, 2026;
originally announced July 2026.
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Pulse magnet of 10 T for power laser experiments with x-ray free-electron laser diagnostics
Authors:
Akihiko Ikeda,
Kosuke Noda,
Yutaro Yamanaka,
Yuma Urabe,
Keiichiro Kawai,
Yasuhiro H. Matsuda,
Hirotaka Nakamura,
Ryusuke Yamamoto,
Yoshiki Naito,
Yasuhiro Kuramitsu,
Kai Taketoshi,
Naoki Yamagata,
Norimasa Ozaki,
Tatiana Pikuz,
Yoichi Sakawa,
Takayoshi Sano,
Ryosuke Kodama,
Taichi Morita,
Tomoya Ogawa,
Kohei Miyanishi,
Toshinori Yabuuchi,
Rigon Gabriel,
Bakandreas Stavros,
Koenig Michel,
Bruno Albertazzi
Abstract:
The importance of investigating magnetized plasmas/solids in extreme conditions has grown over the last decades, particularly in the field of high energy density physics (HEDP), such as laboratory astrophysics and inertial confinement fusion. However, up to now, the unique capabilities of an X-ray free-electron laser (XFEL), such as high brilliance and low divergence have never been exploited for…
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The importance of investigating magnetized plasmas/solids in extreme conditions has grown over the last decades, particularly in the field of high energy density physics (HEDP), such as laboratory astrophysics and inertial confinement fusion. However, up to now, the unique capabilities of an X-ray free-electron laser (XFEL), such as high brilliance and low divergence have never been exploited for this type of research. In this paper, we present the first platform developed at SACLA, Japan, that combines a high-power optical laser for generating matter under extreme conditions of pressure and temperature, an XFEL probe, and an external magnetic field. The high current is produced using a 2 kV, 4.8 kJ pulsed power system giving a maximum current of 10 kA which is synchronized with the optical laser and XFEL in a vacuum environment. It flows through a split-pair coil to generate a high magnetic field (10 T at 6 kA) which has 1 cm access every 45$^{\circ}$ in the equatorial plane and 90$^{\circ}$ in the poloidal one. This platform offers new opportunities to study high-energy-density matter in strong magnetic fields, including shock propagation, instability growth, and turbulent plasma dynamics.
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Submitted 25 May, 2026;
originally announced May 2026.
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Omics-scale polymer computational database transferable to real-world artificial intelligence applications
Authors:
Ryo Yoshida,
Yoshihiro Hayashi,
Hidemine Furuya,
Ryohei Hosoya,
Kazuyoshi Kaneko,
Hiroki Sugisawa,
Yu Kaneko,
Aiko Takahashi,
Yoh Noguchi,
Shun Nanjo,
Keiko Shinoda,
Tomu Hamakawa,
Mitsuru Ohno,
Takuya Kitamura,
Misaki Yonekawa,
Stephen Wu,
Masato Ohnishi,
Chang Liu,
Teruki Tsurimoto,
Arifin,
Araki Wakiuchi,
Kohei Noda,
Junko Morikawa,
Teruaki Hayakawa,
Junichiro Shiomi
, et al. (81 additional authors not shown)
Abstract:
Developing large-scale foundational datasets is a critical milestone in advancing artificial intelligence (AI)-driven scientific innovation. However, unlike AI-mature fields such as natural language processing, materials science, particularly polymer research, has significantly lagged in developing extensive open datasets. This lag is primarily due to the high costs of polymer synthesis and proper…
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Developing large-scale foundational datasets is a critical milestone in advancing artificial intelligence (AI)-driven scientific innovation. However, unlike AI-mature fields such as natural language processing, materials science, particularly polymer research, has significantly lagged in developing extensive open datasets. This lag is primarily due to the high costs of polymer synthesis and property measurements, along with the vastness and complexity of the chemical space. This study presents PolyOmics, an omics-scale computational database generated through fully automated molecular dynamics simulation pipelines that provide diverse physical properties for over $10^5$ polymeric materials. The PolyOmics database is collaboratively developed by approximately 260 researchers from 48 institutions to bridge the gap between academia and industry. Machine learning models pretrained on PolyOmics can be efficiently fine-tuned for a wide range of real-world downstream tasks, even when only limited experimental data are available. Notably, the generalisation capability of these simulation-to-real transfer models improve significantly as the size of the PolyOmics database increases, exhibiting power-law scaling. The emergence of scaling laws supports the "more is better" principle, highlighting the significance of ultralarge-scale computational materials data for improving real-world prediction performance. This unprecedented omics-scale database reveals vast unexplored regions of polymer materials, providing a foundation for AI-driven polymer science.
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Submitted 7 November, 2025;
originally announced November 2025.
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The LED calibration systems for the mDOM and D-Egg sensor modules of the IceCube Upgrade
Authors:
R. Abbasi,
M. Ackermann,
J. Adams,
S. K. Agarwalla,
J. A. Aguilar,
M. Ahlers,
J. M. Alameddine,
S. Ali,
N. M. Amin,
K. Andeen,
C. Argüelles,
Y. Ashida,
S. Athanasiadou,
S. N. Axani,
R. Babu,
X. Bai,
J. Baines-Holmes,
A. Balagopal V.,
S. W. Barwick,
S. Bash,
V. Basu,
R. Bay,
J. J. Beatty,
J. Becker Tjus,
P. Behrens
, et al. (410 additional authors not shown)
Abstract:
The IceCube Neutrino Observatory, instrumenting about 1 km$^3$ of deep, glacial ice at the geographic South Pole, is due to be enhanced with the IceCube Upgrade. The IceCube Upgrade, to be deployed during the 2025/26 Antarctic summer season, will consist of seven new strings of photosensors, densely embedded near the bottom center of the existing array. Aside from a world-leading sensitivity to ne…
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The IceCube Neutrino Observatory, instrumenting about 1 km$^3$ of deep, glacial ice at the geographic South Pole, is due to be enhanced with the IceCube Upgrade. The IceCube Upgrade, to be deployed during the 2025/26 Antarctic summer season, will consist of seven new strings of photosensors, densely embedded near the bottom center of the existing array. Aside from a world-leading sensitivity to neutrino oscillations, a primary goal is the improvement of the calibration of the optical properties of the instrumented ice. These will be applied to the entire archive of IceCube data, improving the angular and energy resolution of the detected neutrino events. For this purpose, the Upgrade strings include a host of new calibration devices. Aside from dedicated calibration modules, several thousand LED flashers have been incorporated into the photosensor modules. We describe the design, production, and testing of these LED flashers before their integration into the sensor modules as well as the use of the LED flashers during lab testing of assembled sensor modules.
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Submitted 5 August, 2025;
originally announced August 2025.
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Acceptance Tests of more than 10 000 Photomultiplier Tubes for the multi-PMT Digital Optical Modules of the IceCube Upgrade
Authors:
R. Abbasi,
M. Ackermann,
J. Adams,
S. K. Agarwalla,
J. A. Aguilar,
M. Ahlers,
J. M. Alameddine,
N. M. Amin,
K. Andeen,
C. Argüelles,
Y. Ashida,
S. Athanasiadou,
L. Ausborm,
S. N. Axani,
X. Bai,
A. Balagopal V.,
M. Baricevic,
S. W. Barwick,
S. Bash,
V. Basu,
R. Bay,
J. J. Beatty,
J. Becker Tjus,
J. Beise,
C. Bellenghi
, et al. (399 additional authors not shown)
Abstract:
More than 10,000 photomultiplier tubes (PMTs) with a diameter of 80 mm will be installed in multi-PMT Digital Optical Modules (mDOMs) of the IceCube Upgrade. These have been tested and pre-calibrated at two sites. A throughput of more than 1000 PMTs per week with both sites was achieved with a modular design of the testing facilities and highly automated testing procedures. The testing facilities…
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More than 10,000 photomultiplier tubes (PMTs) with a diameter of 80 mm will be installed in multi-PMT Digital Optical Modules (mDOMs) of the IceCube Upgrade. These have been tested and pre-calibrated at two sites. A throughput of more than 1000 PMTs per week with both sites was achieved with a modular design of the testing facilities and highly automated testing procedures. The testing facilities can easily be adapted to other PMTs, such that they can, e.g., be re-used for testing the PMTs for IceCube-Gen2. Single photoelectron response, high voltage dependence, time resolution, prepulse, late pulse, afterpulse probabilities, and dark rates were measured for each PMT. We describe the design of the testing facilities, the testing procedures, and the results of the acceptance tests.
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Submitted 20 June, 2024; v1 submitted 30 April, 2024;
originally announced April 2024.
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Extension of measurement range in OCDR based on double-modulation scheme
Authors:
Mana Sakamoto,
Tomoya Miyamae,
Kohei Noda,
Kentaro Nakamura,
Heeyoung Lee,
Yosuke Mizuno
Abstract:
We extend the measurement range of optical correlation-domain reflectometry (OCDR) by modulating the laser output frequency at two frequencies, while preserving spatial resolution. We demonstrate distributed reflectivity sensing with a ten-fold extended measurement range.
We extend the measurement range of optical correlation-domain reflectometry (OCDR) by modulating the laser output frequency at two frequencies, while preserving spatial resolution. We demonstrate distributed reflectivity sensing with a ten-fold extended measurement range.
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Submitted 20 May, 2023;
originally announced September 2023.
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Fiber-optic temperature sensing probe using low-coherence light source
Authors:
Kanon Toda,
Kenta Otsubo,
Kohei Noda,
Heeyoung Lee,
Kentaro Nakamura,
Yosuke Mizuno
Abstract:
We present a new approach for measuring fiber tip temperature using low-coherence Brillouin optical correlation-domain reflectometry, which eliminates the need for an independent reference path and does not entail specific processing of the fiber tip.
We present a new approach for measuring fiber tip temperature using low-coherence Brillouin optical correlation-domain reflectometry, which eliminates the need for an independent reference path and does not entail specific processing of the fiber tip.
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Submitted 20 May, 2023;
originally announced July 2023.
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Investigation of guidelines for improving spatial resolution in direct-modulation BOCDR
Authors:
Seiga Ochi,
Kouta Ozaki,
Kohei Noda,
Heeyoung Lee,
Kentaro Nakamura,
Yosuke Mizuno
Abstract:
The spatial resolution of direct-modulation Brillouin optical correlation-domain reflectometry is studied with respect to modulation amplitude and frequency. Results suggest that optimal resolution improvement is achieved by increasing modulation amplitude first, followed by frequency.
The spatial resolution of direct-modulation Brillouin optical correlation-domain reflectometry is studied with respect to modulation amplitude and frequency. Results suggest that optimal resolution improvement is achieved by increasing modulation amplitude first, followed by frequency.
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Submitted 5 May, 2023;
originally announced May 2023.
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High-resolution low-coherence Brillouin optical correlation-domain reflectometry with suppressed systematic error
Authors:
Kenta Otsubo,
Takaki Kiyozumi,
Kohei Noda,
Kentaro Nakamura,
Heeyoung Lee,
Yosuke Mizuno
Abstract:
We show that the systematic error unique to Brillouin optical correlation-domain reflectometry (BOCDR) can be effectively suppressed by use of low-coherence light, and demonstrate distributed strain measurement with ~3 cm spatial resolution.
We show that the systematic error unique to Brillouin optical correlation-domain reflectometry (BOCDR) can be effectively suppressed by use of low-coherence light, and demonstrate distributed strain measurement with ~3 cm spatial resolution.
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Submitted 20 April, 2023;
originally announced April 2023.
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Observation of Rayleigh scattering by simplified optical correlation-domain reflectometry without frequency shifter
Authors:
Tomoya Miyamae,
Zhu Guangtao,
Takaki Kiyozumi,
Kohei Noda,
Heeyoung Lee,
Kentaro Nakamura,
Yosuke Mizuno
Abstract:
We present a method for measuring the transmission loss of an optical fiber using simplified optical correlation-domain reflectometry. By intentionally lowering the spatial resolution of the system, we observe the Rayleigh scattered signal for the first time without the need for a frequency shifter. Using this method, we simultaneously measure the transmission loss, location, and loss of faulty co…
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We present a method for measuring the transmission loss of an optical fiber using simplified optical correlation-domain reflectometry. By intentionally lowering the spatial resolution of the system, we observe the Rayleigh scattered signal for the first time without the need for a frequency shifter. Using this method, we simultaneously measure the transmission loss, location, and loss of faulty connections along a 10-km-long fiber under test by performing distributed reflected-power measurements of Rayleigh scattering and Fresnel reflection.
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Submitted 15 March, 2023;
originally announced March 2023.
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High-speed high-resolution optical correlation-domain reflectometry without using electrical spectrum analyzer
Authors:
Guangtao Zhu,
Tomoya Miyamae,
Kohei Noda,
Heeyoung Lee,
Kentaro Nakamura,
Yosuke Mizuno
Abstract:
We propose a newly configured optical correlation-domain reflectometry (OCDR) without the use of an electrical spectrum analyzer (ESA) for high-speed distributed reflectivity measurement with an enhanced spatial resolution. First, the operation of ESA-free OCDR is analyzed by numerical simulation, the results of which show the potential of the configuration to perform distributed reflectivity meas…
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We propose a newly configured optical correlation-domain reflectometry (OCDR) without the use of an electrical spectrum analyzer (ESA) for high-speed distributed reflectivity measurement with an enhanced spatial resolution. First, the operation of ESA-free OCDR is analyzed by numerical simulation, the results of which show the potential of the configuration to perform distributed reflectivity measurement with an improved spatial resolution. Subsequently, the simulation results are verified by comparison experiments, where distributed reflectivity measurements along a 32-m-long single-mode fiber joint with multiple connectors are performed using both conventional (with averaging) and ESA-free OCDR configurations (without averaging) at a repetition rate of 100 Hz. The widths of the reflectivity peaks experimentally obtained by the conventional and ESA-free OCDR configurations are 22.9 cm and 7.0 cm, respectively. Finally, we experimentally evaluated the performance of the ESA-free OCDR at higher repetition rates, achieving 6.3-cm spatial resolution at a repetition rate of 1 kHz. This result indicates that the ESA-free OCDR can perform a distributed reflectivity measurement with an improved spatial resolution at a higher operation speed than ever.
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Submitted 26 August, 2022;
originally announced August 2022.
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Very High-Energy Gamma-Ray Follow-Up Program Using Neutrino Triggers from IceCube
Authors:
IceCube Collaboration,
M. G. Aartsen,
K. Abraham,
M. Ackermann,
J. Adams,
J. A. Aguilar,
M. Ahlers,
M. Ahrens,
D. Altmann,
K. Andeen,
T. Anderson,
I. Ansseau,
G. Anton,
M. Archinger,
C. Arguelles,
J. Auffenberg,
S. Axani,
X. Bai,
S. W. Barwick,
V. Baum,
R. Bay,
J. J. Beatty,
J. Becker-Tjus,
K. -H. Becker,
S. BenZvi
, et al. (519 additional authors not shown)
Abstract:
We describe and report the status of a neutrino-triggered program in IceCube that generates real-time alerts for gamma-ray follow-up observations by atmospheric-Cherenkov telescopes (MAGIC and VERITAS). While IceCube is capable of monitoring the whole sky continuously, high-energy gamma-ray telescopes have restricted fields of view and in general are unlikely to be observing a potential neutrino-f…
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We describe and report the status of a neutrino-triggered program in IceCube that generates real-time alerts for gamma-ray follow-up observations by atmospheric-Cherenkov telescopes (MAGIC and VERITAS). While IceCube is capable of monitoring the whole sky continuously, high-energy gamma-ray telescopes have restricted fields of view and in general are unlikely to be observing a potential neutrino-flaring source at the time such neutrinos are recorded. The use of neutrino-triggered alerts thus aims at increasing the availability of simultaneous multi-messenger data during potential neutrino flaring activity, which can increase the discovery potential and constrain the phenomenological interpretation of the high-energy emission of selected source classes (e.g. blazars). The requirements of a fast and stable online analysis of potential neutrino signals and its operation are presented, along with first results of the program operating between 14 March 2012 and 31 December 2015.
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Submitted 12 November, 2016; v1 submitted 6 October, 2016;
originally announced October 2016.
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Electron string ion sources for carbon ion cancer therapy accelerators
Authors:
A. Yu. Boytsov,
D. E. Donets,
E. D. Donets,
E. E. Donets,
K. Katagiri,
K. Noda,
D. O. Ponkin,
A. Yu. Ramzdorf,
V. V. Salnikov,
V. B. Shutov
Abstract:
The Electron String type of Ion Sources (ESIS) was developed, constructed and tested first in the Joint Institute for Nuclear Research. These ion sources can be the appropriate sources for production of pulsed C4+ and C6+ ion beams which can be used for cancer therapy accelerators. In fact the test ESIS Krion-6T already now at the solenoid magnetic field only 4.6 T provides more than 10^10 C4+ ion…
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The Electron String type of Ion Sources (ESIS) was developed, constructed and tested first in the Joint Institute for Nuclear Research. These ion sources can be the appropriate sources for production of pulsed C4+ and C6+ ion beams which can be used for cancer therapy accelerators. In fact the test ESIS Krion-6T already now at the solenoid magnetic field only 4.6 T provides more than 10^10 C4+ ions per pulse and about 5*10^9 C6+ ions per pulse. Such ion sources could be suitable for application at synchrotrons. It was also found, that Krion-6T can provide more than 10^11 C6+ ions per second at 100 Hz repetition rate, and the repetition rate can be increased at the same or larger ion output per second. This makes ESIS applicable at cyclotrons as well. As for production of 11C radioactive ion beams ESIS can be the most economic kind of ion source. To proof that the special cryogenic cell for pulse injection of gaseous species into electron string was successfully tested using the ESIS Krion-2M.
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Submitted 12 March, 2015;
originally announced March 2015.
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Robust dual-field optimization of scanned ion beams against range and setup uncertainties
Authors:
Taku Inaniwa,
Nobuyuki Kanematsu,
Takuji Furukawa,
Koji Noda
Abstract:
A 'dual-field' strategy is often used for tumors with highly complex shapes and/or with large volumes exceeding available field-size in both passive and scanning irradiations with ion beams. Range and setup uncertainties can cause hot and cold doses at the field junction within the target. Such uncertainties will also cause cold doses in the peripheral region of the target. We have developed an al…
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A 'dual-field' strategy is often used for tumors with highly complex shapes and/or with large volumes exceeding available field-size in both passive and scanning irradiations with ion beams. Range and setup uncertainties can cause hot and cold doses at the field junction within the target. Such uncertainties will also cause cold doses in the peripheral region of the target. We have developed an algorithm to reduce the sensitivity of the dual-field plan to these uncertainties in scanning irradiations. This algorithm is composed of the following two steps: 1) generating the expanded target volume, and 2) solving the inverse problem where the terms suppressing the dose gradient of individual fields are added into the objective function. The validity of this algorithm is demonstrated through the simulation studies for three extreme cases of two fields with unidirectional, opposing and orthogonal geometries. With the proposed algorithm, we can obtain a more robust plan to minimize the effects of range and setup uncertainties than the conventional plan. Compared to that for the conventional plan, the optimization time for the robust plan increased by a factor of approximately three.
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Submitted 5 October, 2010;
originally announced October 2010.
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Direct evaporative cooling of 41K into a Bose-Einstein condensate
Authors:
T. Kishimoto,
J. Kobayashi,
K. Noda,
K. Aikawa,
M. Ueda,
S. Inouye
Abstract:
We have investigated the collisional properties of 41K atoms at ultracold temperature. To show the possibility to use 41K as a coolant, a Bose-Einstein condensate of 41K atoms in the stretched state (F=2, m_F=2) was created for the first time by direct evaporation in a magnetic trap. An upper bound of three body loss coefficient for atoms in the condensate was determined to be 4(2) 10^{-29} cm -…
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We have investigated the collisional properties of 41K atoms at ultracold temperature. To show the possibility to use 41K as a coolant, a Bose-Einstein condensate of 41K atoms in the stretched state (F=2, m_F=2) was created for the first time by direct evaporation in a magnetic trap. An upper bound of three body loss coefficient for atoms in the condensate was determined to be 4(2) 10^{-29} cm -6 s-1. A Feshbach resonance in the F=1, m_F=-1 state was observed at 51.42(5) G, which is in good agreement with theoretical prediction.
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Submitted 23 December, 2008;
originally announced December 2008.