-
QSHS: An Axion Dark Matter Resonant Search Apparatus
Authors:
A. Alsulami,
I. Bailey,
G. Carosi,
G. Chapman,
B. Chakraborty,
E. J. Daw,
N. Du,
S. Durham,
J. Esmenda,
J. Gallop,
T. Gamble,
T. Godfrey,
G. Gregori,
J. Halliday,
L. Hao,
E. Hardy,
E. A. Laird,
P. Leek,
J. March-Russell,
P. J. Meeson,
C. F. Mostyn,
Yu. A. Pashkin,
S. O. Peatain,
M. Perry,
M. Piscitelli
, et al. (10 additional authors not shown)
Abstract:
We describe a resonant cavity search apparatus for axion dark matter constructed by the Quantum Sensors for the Hidden Sector (QSHS) collaboration. The apparatus is configured to search for QCD axion dark matter, though also has the capability to detect axion-like particles (ALPs), dark photons, and some other forms of wave-like dark matter. Initially, a tuneable cylindrical oxygen-free copper cav…
▽ More
We describe a resonant cavity search apparatus for axion dark matter constructed by the Quantum Sensors for the Hidden Sector (QSHS) collaboration. The apparatus is configured to search for QCD axion dark matter, though also has the capability to detect axion-like particles (ALPs), dark photons, and some other forms of wave-like dark matter. Initially, a tuneable cylindrical oxygen-free copper cavity is read out using a low noise microwave amplifier feeding a heterodyne receiver. The cavity is housed in a dilution refrigerator and threaded by a solenoidal magnetic field, nominally 8T. The apparatus also houses a magnetic field shield for housing superconducting electronics, and several other fixed-frequency resonators for use in testing and commissioning various prototype quantum electronic devices sensitive at a range of axion masses in the range 2.0 to 40 micro-eV/c2. The apparatus as currently configured is intended as a test stand for electronics over the relatively wide frequency band attainable with the TM010 cavity mode used for axion searches. We present performance data for the resonator, dilution refrigerator, and magnet, and plans for the first science run.
△ Less
Submitted 15 September, 2025; v1 submitted 16 April, 2025;
originally announced April 2025.
-
Transverse Emittance Reduction in Muon Beams by Ionization Cooling
Authors:
The MICE Collaboration,
M. Bogomilov,
R. Tsenov,
G. Vankova-Kirilova,
Y. P. Song,
J. Y. Tang,
Z. H. Li,
R. Bertoni,
M. Bonesini,
F. Chignoli,
R. Mazza,
A. de Bari,
D. Orestano,
L. Tortora,
Y. Kuno,
H. Sakamoto,
A. Sato,
S. Ishimoto,
M. Chung,
C. K. Sung,
F. Filthaut,
M. Fedorov,
D. Jokovic,
D. Maletic,
M. Savic
, et al. (112 additional authors not shown)
Abstract:
Accelerated muon beams have been considered for next-generation studies of high-energy lepton-antilepton collisions and neutrino oscillations. However, high-brightness muon beams have not yet been produced. The main challenge for muon acceleration and storage stems from the large phase-space volume occupied by the beam, derived from the muon production mechanism through the decay of pions from pro…
▽ More
Accelerated muon beams have been considered for next-generation studies of high-energy lepton-antilepton collisions and neutrino oscillations. However, high-brightness muon beams have not yet been produced. The main challenge for muon acceleration and storage stems from the large phase-space volume occupied by the beam, derived from the muon production mechanism through the decay of pions from proton collisions. Ionization cooling is the technique proposed to decrease the muon beam phase-space volume. Here we demonstrate a clear signal of ionization cooling through the observation of transverse emittance reduction in beams that traverse lithium hydride or liquid hydrogen absorbers in the Muon Ionization Cooling Experiment (MICE). The measurement is well reproduced by the simulation of the experiment and the theoretical model. The results shown here represent a substantial advance towards the realization of muon-based facilities that could operate at the energy and intensity frontiers.
△ Less
Submitted 13 October, 2023; v1 submitted 9 October, 2023;
originally announced October 2023.
-
Evolution of dynamic fibrils from the cooler chromosphere to the hotter corona
Authors:
Sudip Mandal,
Hardi Peter,
Lakshmi Pradeep Chitta,
Sami K. Solanki,
Regina Aznar Cuadrado,
Udo Schühle,
Luca Teriaca,
Juan Martínez Sykora,
David Berghmans,
Frédéric Auchère,
Susanna Parenti,
Andrei N. Zhukov,
Éric Buchlin,
Cis Verbeeck,
Emil Kraaikamp,
Luciano Rodriguez,
David M. Long,
Krzysztof Barczynski,
Gabriel Pelouze,
Philip J. Smith
Abstract:
Dynamic fibrils (DFs) are commonly observed chromospheric features in solar active regions. Recent observations from the Extreme Ultraviolet Imager (EUI) aboard the Solar Orbiter have revealed unambiguous signatures of DFs at the coronal base, in extreme ultraviolet (EUV) emission. However, it remains unclear if the DFs detected in the EUV are linked to their chromospheric counterparts. Simultaneo…
▽ More
Dynamic fibrils (DFs) are commonly observed chromospheric features in solar active regions. Recent observations from the Extreme Ultraviolet Imager (EUI) aboard the Solar Orbiter have revealed unambiguous signatures of DFs at the coronal base, in extreme ultraviolet (EUV) emission. However, it remains unclear if the DFs detected in the EUV are linked to their chromospheric counterparts. Simultaneous detection of DFs from chromospheric to coronal temperatures could provide important information on their thermal structuring and evolution through the solar atmosphere. In this paper, we address this question by using coordinated EUV observations from the Atmospheric Imaging Assembly (AIA), Interface Region Imaging Spectrograph (IRIS), and EUI to establish a one-to-one correspondence between chromospheric and transition region DFs (observed by IRIS) with their coronal counterparts (observed by EUI and AIA). Our analysis confirms a close correspondence between DFs observed at different atmospheric layers, and reveals that DFs can reach temperatures of about 1.5 million Kelvin, typical of the coronal base in active regions. Furthermore, intensity evolution of these DFs, as measured by tracking them over time, reveals a shock-driven scenario in which plasma piles up near the tips of these DFs and, subsequently, these tips appear as bright blobs in coronal images. These findings provide information on the thermal structuring of DFs and their evolution and impact through the solar atmosphere.
△ Less
Submitted 10 September, 2023;
originally announced September 2023.
-
Picoflare jets power the solar wind emerging from a coronal hole on the Sun
Authors:
L. P. Chitta,
A. N. Zhukov,
D. Berghmans,
H. Peter,
S. Parenti,
S. Mandal,
R. Aznar Cuadrado,
U. Schühle,
L. Teriaca,
F. Auchère,
K. Barczynski,
É. Buchlin,
L. Harra,
E. Kraaikamp,
D. M. Long,
L. Rodriguez,
C. Schwanitz,
P. J. Smith,
C. Verbeeck,
D. B. Seaton
Abstract:
Coronal holes are areas on the Sun with open magnetic field lines. They are a source region of the solar wind, but how the wind emerges from coronal holes is not known. We observed a coronal hole using the Extreme Ultraviolet Imager on the Solar Orbiter spacecraft. We identified jets on scales of a few hundred kilometers, which last 20 to 100 seconds and reach speeds of ~100 kilometers per second.…
▽ More
Coronal holes are areas on the Sun with open magnetic field lines. They are a source region of the solar wind, but how the wind emerges from coronal holes is not known. We observed a coronal hole using the Extreme Ultraviolet Imager on the Solar Orbiter spacecraft. We identified jets on scales of a few hundred kilometers, which last 20 to 100 seconds and reach speeds of ~100 kilometers per second. The jets are powered by magnetic reconnection and have kinetic energy in the picoflare range. They are intermittent but widespread within the observed coronal hole. We suggest that such picoflare jets could produce enough high-temperature plasma to sustain the solar wind and that the wind emerges from coronal holes as a highly intermittent outflow at small scales.
△ Less
Submitted 24 August, 2023;
originally announced August 2023.
-
Ultra-high-resolution Observations of Persistent Null-point Reconnection in the Solar Corona
Authors:
X. Cheng,
E. R. Priest,
H. T. Li,
J. Chen,
G. Aulanier,
L. P. Chitta,
Y. L. Wang,
H. Peter,
X. S. Zhu,
C. Xing,
M. D. Ding,
S. K. Solanki,
D. Berghmans,
L. Teriaca,
R. Aznar Cuadrado,
A. N. Zhukov,
Y. Guo,
D. Long,
L. Harra,
P. J. Smith,
L. Rodriguez,
C. Verbeeck,
K. Barczynski,
S. Parenti
Abstract:
Magnetic reconnection is a key mechanism involved in solar eruptions and is also a prime possibility to heat the low corona to millions of degrees. Here, we present ultra-high-resolution extreme ultraviolet observations of persistent null-point reconnection in the corona at a scale of about 390 km over one hour observations of the Extreme-Ultraviolet Imager on board Solar Orbiter spacecraft. The o…
▽ More
Magnetic reconnection is a key mechanism involved in solar eruptions and is also a prime possibility to heat the low corona to millions of degrees. Here, we present ultra-high-resolution extreme ultraviolet observations of persistent null-point reconnection in the corona at a scale of about 390 km over one hour observations of the Extreme-Ultraviolet Imager on board Solar Orbiter spacecraft. The observations show formation of a null-point configuration above a minor positive polarity embedded within a region of dominant negative polarity near a sunspot. The gentle phase of the persistent null-point reconnection is evidenced by sustained point-like high-temperature plasma (about 10 MK) near the null-point and constant outflow blobs not only along the outer spine but also along the fan surface. The blobs appear at a higher frequency than previously observed with an average velocity of about 80 km/s and life-times of about 40 s. The null-point reconnection also occurs explosively but only for 4 minutes, its coupling with a mini-filament eruption generates a spiral jet. These results suggest that magnetic reconnection, at previously unresolved scales, proceeds continually in a gentle and/or explosive way to persistently transfer mass and energy to the overlying corona.
△ Less
Submitted 18 April, 2023;
originally announced April 2023.
-
First Perihelion of EUI on the Solar Orbiter mission
Authors:
D. Berghmans,
P. Antolin,
F. Auchère,
R. Aznar Cuadrado,
K. Barczynski,
L. P. Chitta,
S. Gissot,
L. Harra,
Z. Huang,
M. Janvier,
E. Kraaikamp,
D. M. Long,
S. Mandal,
M. Mierla,
S. Parenti,
H. Peter,
L. Rodriguez,
U. Schühle,
P. J. Smith,
S. K. Solanki,
K. Stegen,
L. Teriaca,
C. Verbeeck,
M. J. West,
A. N. Zhukov
, et al. (12 additional authors not shown)
Abstract:
Context. The Extreme Ultraviolet Imager (EUI), onboard Solar Orbiter consists of three telescopes: the two High Resolution Imagers in EUV (HRIEUV) and in Lyman-α (HRILya), and the Full Sun Imager (FSI). Solar Orbiter/EUI started its Nominal Mission Phase on 2021 November 27. Aims. EUI images from the largest scales in the extended corona off limb, down to the smallest features at the base of the c…
▽ More
Context. The Extreme Ultraviolet Imager (EUI), onboard Solar Orbiter consists of three telescopes: the two High Resolution Imagers in EUV (HRIEUV) and in Lyman-α (HRILya), and the Full Sun Imager (FSI). Solar Orbiter/EUI started its Nominal Mission Phase on 2021 November 27. Aims. EUI images from the largest scales in the extended corona off limb, down to the smallest features at the base of the corona and chromosphere. EUI is therefore a key instrument for the connection science that is at the heart of the Solar Orbiter mission science goals. Methods. The highest resolution on the Sun is achieved when Solar Orbiter passes through the perihelion part of its orbit. On 2022 March 26, Solar Orbiter reached for the first time a distance to the Sun close to 0.3 au. No other coronal EUV imager has been this close to the Sun. Results. We review the EUI data sets obtained during the period 2022 March-April, when Solar Orbiter quickly moved from alignment with the Earth (2022 March 6), to perihelion (2022 March 26), to quadrature with the Earth (2022 March 29). We highlight the first observational results in these unique data sets and we report on the in-flight instrument performance. Conclusions. EUI has obtained the highest resolution images ever of the solar corona in the quiet Sun and polar coronal holes. Several active regions were imaged at unprecedented cadences and sequence durations. We identify in this paper a broad range of features that require deeper studies. Both FSI and HRIEUV operate at design specifications but HRILya suffered from performance issues near perihelion. We conclude emphasising the EUI open data policy and encouraging further detailed analysis of the events highlighted in this paper.
△ Less
Submitted 13 January, 2023;
originally announced January 2023.
-
Solar coronal heating from small-scale magnetic braids
Authors:
L. P. Chitta,
H. Peter,
S. Parenti,
D. Berghmans,
F. Auchère,
S. K. Solanki,
R. Aznar Cuadrado,
U. Schühle,
L. Teriaca,
S. Mandal,
K. Barczynski,
É. Buchlin,
L. Harra,
E. Kraaikamp,
D. M. Long,
L. Rodriguez,
C. Schwanitz,
P. J. Smith,
C. Verbeeck,
A. N. Zhukov,
W. Liu,
M. C. M. Cheung
Abstract:
Relaxation of braided coronal magnetic fields through reconnection is thought to be a source of energy to heat plasma in active region coronal loops. However, observations of active region coronal heating associated with an untangling of magnetic braids remain sparse. One reason for this paucity could be the lack of coronal observations with a sufficiently high spatial and temporal resolution to c…
▽ More
Relaxation of braided coronal magnetic fields through reconnection is thought to be a source of energy to heat plasma in active region coronal loops. However, observations of active region coronal heating associated with an untangling of magnetic braids remain sparse. One reason for this paucity could be the lack of coronal observations with a sufficiently high spatial and temporal resolution to capture this process in action. Using new observations with high spatial resolution (250-270 km on the Sun) and high cadence (3-10 s) from the Extreme Ultraviolet Imager (EUI) on board Solar Orbiter, we observed the untangling of small-scale coronal braids in different active regions. The untangling is associated with impulsive heating of the gas in these braided loops. We assess that coronal magnetic braids overlying cooler chromospheric filamentary structures are perhaps more common. Furthermore, our observations show signatures of spatially coherent and intermittent coronal heating during the relaxation of the magnetic braids. Our study reveals the operation of gentle and impulsive modes of magnetic reconnection in the solar corona.
△ Less
Submitted 26 November, 2022; v1 submitted 25 September, 2022;
originally announced September 2022.
-
Multiple Coulomb Scattering of muons in Lithium Hydride
Authors:
M. Bogomilov,
R. Tsenov,
G. Vankova-Kirilova,
Y. P. Song,
J. Y. Tang,
Z. H. Li,
R. Bertoni,
M. Bonesini,
F. Chignoli,
R. Mazza,
V. Palladino,
A. de Bari,
D. Orestano,
L. Tortora,
Y. Kuno,
H. Sakamoto,
A. Sato,
S. Ishimoto,
M. Chung,
C. K. Sung,
F. Filthaut,
M. Fedorov,
D. Jokovic,
D. Maletic,
M. Savic
, et al. (112 additional authors not shown)
Abstract:
Multiple Coulomb Scattering (MCS) is a well known phenomenon occurring when charged particles traverse materials. Measurements of muons traversing low $Z$ materials made in the MuScat experiment showed that theoretical models and simulation codes, such as GEANT4 (v7.0), over-estimated the scattering. The Muon Ionization Cooling Experiment (MICE) measured the cooling of a muon beam traversing a liq…
▽ More
Multiple Coulomb Scattering (MCS) is a well known phenomenon occurring when charged particles traverse materials. Measurements of muons traversing low $Z$ materials made in the MuScat experiment showed that theoretical models and simulation codes, such as GEANT4 (v7.0), over-estimated the scattering. The Muon Ionization Cooling Experiment (MICE) measured the cooling of a muon beam traversing a liquid hydrogen or lithium hydride (LiH) energy absorber as part of a programme to develop muon accelerator facilities, such as a Neutrino Factory or a Muon Collider. The energy loss and MCS that occur in the absorber material are competing effects that alter the performance of the cooling channel. Therefore measurements of MCS are required in order to validate the simulations used to predict the cooling performance in future accelerator facilities. We report measurements made in the MICE apparatus of MCS using a LiH absorber and muons within the momentum range 160 to 245 MeV/c. The measured RMS scattering width is about 9% smaller than that predicted by the approximate formula proposed by the Particle Data Group. Data at 172, 200 and 240 MeV/c are compared to the GEANT4 (v9.6) default scattering model. These measurements show agreement with this more recent GEANT4 (v9.6) version over the range of incident muon momenta.
△ Less
Submitted 21 September, 2022;
originally announced September 2022.
-
Performance of the MICE diagnostic system
Authors:
The MICE collaboration,
M. Bogomilov,
R. Tsenov,
G. Vankova-Kirilova,
Y. P. Song,
J. Y. Tang,
Z. H. Li,
R. Bertoni,
M. Bonesini,
F. Chignoli,
R. Mazza,
V. Palladino,
A. de Bari,
D. Orestano,
L. Tortora,
Y. Kuno,
H. Sakamoto,
A. Sato,
S. Ishimoto,
M. Chung,
C. K. Sung,
F. Filthaut,
M. Fedorov,
D. Jokovic,
D. Maletic
, et al. (113 additional authors not shown)
Abstract:
Muon beams of low emittance provide the basis for the intense, well-characterised neutrino beams of a neutrino factory and for multi-TeV lepton-antilepton collisions at a muon collider. The international Muon Ionization Cooling Experiment (MICE) has demonstrated the principle of ionization cooling, the technique by which it is proposed to reduce the phase-space volume occupied by the muon beam at…
▽ More
Muon beams of low emittance provide the basis for the intense, well-characterised neutrino beams of a neutrino factory and for multi-TeV lepton-antilepton collisions at a muon collider. The international Muon Ionization Cooling Experiment (MICE) has demonstrated the principle of ionization cooling, the technique by which it is proposed to reduce the phase-space volume occupied by the muon beam at such facilities. This paper documents the performance of the detectors used in MICE to measure the muon-beam parameters, and the physical properties of the liquid hydrogen energy absorber during running.
△ Less
Submitted 16 August, 2021; v1 submitted 10 June, 2021;
originally announced June 2021.
-
First demonstration of ionization cooling by the Muon Ionization Cooling Experiment
Authors:
M. Bogomilov,
R. Tsenov,
G. Vankova-Kirilova,
Y. P. Song,
J. Y. Tang,
Z. H. Li,
R. Bertoni,
M. Bonesini,
F. Chignoli,
R. Mazza,
V. Palladino,
A. de Bari,
D. Orestano,
L. Tortora,
Y. Kuno,
H. Sakamoto,
A. Sato,
S. Ishimoto,
M. Chung,
C. K. Sung,
F. Filthaut,
D. Jokovic,
D. Maletic,
M. Savic,
N. Jovancevic
, et al. (110 additional authors not shown)
Abstract:
High-brightness muon beams of energy comparable to those produced by state-of-the-art electron, proton and ion accelerators have yet to be realised. Such beams have the potential to carry the search for new phenomena in lepton-antilepton collisions to extremely high energy and also to provide uniquely well-characterised neutrino beams. A muon beam may be created through the decay of pions produced…
▽ More
High-brightness muon beams of energy comparable to those produced by state-of-the-art electron, proton and ion accelerators have yet to be realised. Such beams have the potential to carry the search for new phenomena in lepton-antilepton collisions to extremely high energy and also to provide uniquely well-characterised neutrino beams. A muon beam may be created through the decay of pions produced in the interaction of a proton beam with a target. To produce a high-brightness beam from such a source requires that the phase space volume occupied by the muons be reduced (cooled). Ionization cooling is the novel technique by which it is proposed to cool the beam. The Muon Ionization Cooling Experiment collaboration has constructed a section of an ionization cooling cell and used it to provide the first demonstration of ionization cooling. We present these ground-breaking measurements.
△ Less
Submitted 19 July, 2019;
originally announced July 2019.
-
First particle-by-particle measurement of emittance in the Muon Ionization Cooling Experiment
Authors:
The MICE Collaboration,
D. Adams,
D. Adey,
R. Asfandiyarov,
G. Barber,
A. de Bari,
R. Bayes,
V. Bayliss,
R. Bertoni,
V. Blackmore,
A. Blondel,
J. Boehm,
M. Bogomilov,
M. Bonesini,
C. N. Booth,
D. Bowring,
S. Boyd,
T. W. Bradshaw,
A. D. Bross,
C. Brown,
L. Coney,
G. Charnley,
G. T. Chatzitheodoridis,
F. Chignoli,
M. Chung
, et al. (111 additional authors not shown)
Abstract:
The Muon Ionization Cooling Experiment (MICE) collaboration seeks to demonstrate the feasibility of ionization cooling, the technique by which it is proposed to cool the muon beam at a future neutrino factory or muon collider. The emittance is measured from an ensemble of muons assembled from those that pass through the experiment. A pure muon ensemble is selected using a particle-identification s…
▽ More
The Muon Ionization Cooling Experiment (MICE) collaboration seeks to demonstrate the feasibility of ionization cooling, the technique by which it is proposed to cool the muon beam at a future neutrino factory or muon collider. The emittance is measured from an ensemble of muons assembled from those that pass through the experiment. A pure muon ensemble is selected using a particle-identification system that can reject efficiently both pions and electrons. The position and momentum of each muon are measured using a high-precision scintillating-fibre tracker in a 4\,T solenoidal magnetic field. This paper presents the techniques used to reconstruct the phase-space distributions and reports the first particle-by-particle measurement of the emittance of the MICE Muon Beam as a function of muon-beam momentum.
△ Less
Submitted 26 March, 2019; v1 submitted 31 October, 2018;
originally announced October 2018.
-
RF system for the MICE demonstration of ionization cooling
Authors:
K. Ronald,
C. G. Whyte,
A. J. Dick,
A. R. Young,
D. Li,
A. J. DeMello,
A. R. Lambert,
T. Luo,
T. Anderson,
D. Bowring,
A. Bross,
A. Moretti,
R. Pasquinelli,
D. Peterson,
M. Popovic,
R. Schultz,
J. Volk,
Y. Torun,
P. Hanlet,
B. Freemire,
A. Moss,
K. Dumbell,
A. Grant,
C. White,
S. Griffiths
, et al. (7 additional authors not shown)
Abstract:
Muon accelerators offer an attractive option for a range of future particle physics experiments. They can enable high energy (TeV+) high energy lepton colliders whilst mitigating the difficulty of synchrotron losses, and can provide intense beams of neutrinos for fundamental physics experiments investigating the physics of flavor. The method of production of muon beams results in high beam emittan…
▽ More
Muon accelerators offer an attractive option for a range of future particle physics experiments. They can enable high energy (TeV+) high energy lepton colliders whilst mitigating the difficulty of synchrotron losses, and can provide intense beams of neutrinos for fundamental physics experiments investigating the physics of flavor. The method of production of muon beams results in high beam emittance which must be reduced for efficient acceleration. Conventional emittance control schemes take too long, given the very short (2.2 microsecond) rest lifetime of the muon. Ionisation cooling offers a much faster approach to reducing particle emittance, and the international MICE collaboration aims to demonstrate this technique for the first time. This paper will present the MICE RF system and its role in the context of the overall experiment.
△ Less
Submitted 14 September, 2017;
originally announced September 2017.
-
Design and expected performance of the MICE demonstration of ionization cooling
Authors:
MICE Collaboration,
M. Bogomilov,
R. Tsenov,
G. Vankova-Kirilova,
Y. Song,
J. Tang,
Z. Li,
R. Bertoni,
M. Bonesini,
F. Chignoli,
R. Mazza,
V. Palladino,
A. de Bari,
G. Cecchet,
D. Orestano,
L. Tortora,
Y. Kuno,
S. Ishimoto,
F. Filthaut,
D. Jokovic,
D. Maletic,
M. Savic,
O. M. Hansen,
S. Ramberger,
M. Vretenar
, et al. (107 additional authors not shown)
Abstract:
Muon beams of low emittance provide the basis for the intense, well-characterised neutrino beams necessary to elucidate the physics of flavour at a neutrino factory and to provide lepton-antilepton collisions at energies of up to several TeV at a muon collider. The international Muon Ionization Cooling Experiment (MICE) aims to demonstrate ionization cooling, the technique by which it is proposed…
▽ More
Muon beams of low emittance provide the basis for the intense, well-characterised neutrino beams necessary to elucidate the physics of flavour at a neutrino factory and to provide lepton-antilepton collisions at energies of up to several TeV at a muon collider. The international Muon Ionization Cooling Experiment (MICE) aims to demonstrate ionization cooling, the technique by which it is proposed to reduce the phase-space volume occupied by the muon beam at such facilities. In an ionization-cooling channel, the muon beam passes through a material in which it loses energy. The energy lost is then replaced using RF cavities. The combined effect of energy loss and re-acceleration is to reduce the transverse emittance of the beam (transverse cooling). A major revision of the scope of the project was carried out over the summer of 2014. The revised experiment can deliver a demonstration of ionization cooling. The design of the cooling demonstration experiment will be described together with its predicted cooling performance.
△ Less
Submitted 27 January, 2017; v1 submitted 23 January, 2017;
originally announced January 2017.
-
Scale-Bridging Model Development for Coal Particle Devolatilization
Authors:
Benjamin B Schroeder,
Sean T Smith,
Philip J Smith,
Thomas H Fletcher,
Andrew Packard,
Michael Frenklach,
Arun Hegde,
Wenyu Li,
James Oreluk
Abstract:
When performing large-scale, high-performance computations of multi-physics applications, it is common to limit the complexity of physics sub-models comprising the simulation. For a hierarchical system of coal boiler simulations a scale-bridging model is constructed to capture characteristics appropriate for the application-scale from a detailed coal devolatilization model. Such scale-bridging all…
▽ More
When performing large-scale, high-performance computations of multi-physics applications, it is common to limit the complexity of physics sub-models comprising the simulation. For a hierarchical system of coal boiler simulations a scale-bridging model is constructed to capture characteristics appropriate for the application-scale from a detailed coal devolatilization model. Such scale-bridging allows full descriptions of scale-applicable physics, while functioning at reasonable computational costs. This study presents a variation on multi-fidelity modeling with a detailed physics model, the chemical percolation devolatilization model, being used to calibrate a scale-briding model for the application of interest. The application space provides essential context for designing the scale-bridging model by defining scales, determining requirements and weighting desired characteristics. A single kinetic reaction equation with functional yield model and distributed activation energy is implemented to act as the scale-bridging model-form. Consistency constraints are used to locate regions of the scale-bridging model's parameter-space that are consistent with the uncertainty identified within the detailed model. Ultimately, the performance of the scale-bridging model with consistent parameter-sets was assessed against desired characteristics of the detailed model and found to perform satisfactorily in capturing thermodynamic trends and kinetic timescales for the desired application-scale. Framing the process of model-form selection within the context of calibration and uncertainty quantification allows the credibility of the model to be established.
△ Less
Submitted 3 September, 2016;
originally announced September 2016.
-
The design and performance of an improved target for MICE
Authors:
C. N. Booth,
P. Hodgson,
J. Langlands,
E. Overton,
M. Robinson,
P. J. Smith,
G. Barber,
K. R. Long,
B. Shepherd,
E. Capocci,
C. MacWaters,
J. Tarrant
Abstract:
The linear motor driving the target for the Muon Ionisation Cooling Experiment has been redesigned to improve its reliability and performance. A new coil-winding technique is described which produces better magnetic alignment and improves heat transport out of the windings. Improved field-mapping has allowed the more precise construction to be demonstrated, and an enhanced controller exploits the…
▽ More
The linear motor driving the target for the Muon Ionisation Cooling Experiment has been redesigned to improve its reliability and performance. A new coil-winding technique is described which produces better magnetic alignment and improves heat transport out of the windings. Improved field-mapping has allowed the more precise construction to be demonstrated, and an enhanced controller exploits the full features of the hardware, enabling increased acceleration and precision. The new user interface is described and analysis of performance data to monitor friction is shown to allow quality control of bearings and a measure of the ageing of targets during use.
△ Less
Submitted 23 March, 2016;
originally announced March 2016.
-
Pion contamination in the MICE muon beam
Authors:
D. Adams,
A. Alekou,
M. Apollonio,
R. Asfandiyarov,
G. Barber,
P. Barclay,
A. de Bari,
R. Bayes,
V. Bayliss,
R. Bertoni,
V. J. Blackmore,
A. Blondel,
S. Blot,
M. Bogomilov,
M. Bonesini,
C. N. Booth,
D. Bowring,
S. Boyd,
T. W. Bradshaw,
U. Bravar,
A. D. Bross,
M. Capponi,
T. Carlisle,
G. Cecchet,
C. Charnley
, et al. (120 additional authors not shown)
Abstract:
The international Muon Ionization Cooling Experiment (MICE) will perform a systematic investigation of ionization cooling with muon beams of momentum between 140 and 240\,MeV/c at the Rutherford Appleton Laboratory ISIS facility. The measurement of ionization cooling in MICE relies on the selection of a pure sample of muons that traverse the experiment. To make this selection, the MICE Muon Beam i…
▽ More
The international Muon Ionization Cooling Experiment (MICE) will perform a systematic investigation of ionization cooling with muon beams of momentum between 140 and 240\,MeV/c at the Rutherford Appleton Laboratory ISIS facility. The measurement of ionization cooling in MICE relies on the selection of a pure sample of muons that traverse the experiment. To make this selection, the MICE Muon Beam is designed to deliver a beam of muons with less than $\sim$1\% contamination. To make the final muon selection, MICE employs a particle-identification (PID) system upstream and downstream of the cooling cell. The PID system includes time-of-flight hodoscopes, threshold-Cherenkov counters and calorimetry. The upper limit for the pion contamination measured in this paper is $f_π< 1.4\%$ at 90\% C.L., including systematic uncertainties. Therefore, the MICE Muon Beam is able to meet the stringent pion-contamination requirements of the study of ionization cooling.
△ Less
Submitted 10 February, 2016; v1 submitted 2 November, 2015;
originally announced November 2015.
-
Electron-Muon Ranger: performance in the MICE Muon Beam
Authors:
D. Adams,
A. Alekou,
M. Apollonio,
R. Asfandiyarov,
G. Barber,
P. Barclay,
A. de Bari,
R. Bayes,
V. Bayliss,
P. Bene,
R. Bertoni,
V. J. Blackmore,
A. Blondel,
S. Blot,
M. Bogomilov,
M. Bonesini,
C. N. Booth,
D. Bowring,
S. Boyd,
T. W. Bradshaw,
U. Bravar,
A. D. Bross,
F. Cadoux,
M. Capponi,
T. Carlisle
, et al. (129 additional authors not shown)
Abstract:
The Muon Ionization Cooling Experiment (MICE) will perform a detailed study of ionization cooling to evaluate the feasibility of the technique. To carry out this program, MICE requires an efficient particle-identification (PID) system to identify muons. The Electron-Muon Ranger (EMR) is a fully-active tracking-calorimeter that forms part of the PID system and tags muons that traverse the cooling c…
▽ More
The Muon Ionization Cooling Experiment (MICE) will perform a detailed study of ionization cooling to evaluate the feasibility of the technique. To carry out this program, MICE requires an efficient particle-identification (PID) system to identify muons. The Electron-Muon Ranger (EMR) is a fully-active tracking-calorimeter that forms part of the PID system and tags muons that traverse the cooling channel without decaying. The detector is capable of identifying electrons with an efficiency of 98.6%, providing a purity for the MICE beam that exceeds 99.8%. The EMR also proved to be a powerful tool for the reconstruction of muon momenta in the range 100-280 MeV/$c$.
△ Less
Submitted 3 November, 2015; v1 submitted 28 October, 2015;
originally announced October 2015.
-
nuSTORM - Neutrinos from STORed Muons: Proposal to the Fermilab PAC
Authors:
D. Adey,
S. K. Agarwalla,
C. M. Ankenbrandt,
R. Asfandiyarov,
J. J. Back,
G. Barker,
E. Baussan,
R. Bayes,
S. Bhadra,
V. Blackmore,
A. Blondel,
S. A. Bogacz,
C. Booth,
S. B. Boyd,
A. Bravar,
S. J. Brice,
A. D. Bross,
F. Cadoux,
H. Cease,
A. Cervera,
J. Cobb,
D. Colling,
P. Coloma,
L. Coney,
A. Dobbs
, et al. (88 additional authors not shown)
Abstract:
The nuSTORM facility has been designed to deliver beams of electron neutrinos and muon neutrinos (and their anti-particles) from the decay of a stored muon beam with a central momentum of 3.8 GeV/c and a momentum acceptance of 10%. The facility is unique in that it will: 1. Allow searches for sterile neutrinos of exquisite sensitivity to be carried out; 2. Serve future long- and short-baseline neu…
▽ More
The nuSTORM facility has been designed to deliver beams of electron neutrinos and muon neutrinos (and their anti-particles) from the decay of a stored muon beam with a central momentum of 3.8 GeV/c and a momentum acceptance of 10%. The facility is unique in that it will: 1. Allow searches for sterile neutrinos of exquisite sensitivity to be carried out; 2. Serve future long- and short-baseline neutrino-oscillation programs by providing definitive measurements of electron neutrino and muon neutrino scattering cross sections off nuclei with percent-level precision; and 3. Constitutes the crucial first step in the development of muon accelerators as a powerful new technique for particle physics. The document describes the facility in detail and demonstrates its physics capabilities. This document was submitted to the Fermilab Physics Advisory Committee in consideration for Stage I approval.
△ Less
Submitted 31 July, 2013;
originally announced August 2013.
-
Coarse-graining DNA for simulations of DNA nanotechnology
Authors:
Jonathan P. K. Doye,
Thomas E. Ouldridge,
Ard A. Louis,
Flavio Romano,
Petr Sulc,
Christian Matek,
Benedict E. K. Snodin,
Lorenzo Rovigatti,
John S. Schreck,
Ryan M. Harrison,
William P. J. Smith
Abstract:
To simulate long time and length scale processes involving DNA it is necessary to use a coarse-grained description. Here we provide an overview of different approaches to such coarse graining, focussing on those at the nucleotide level that allow the self-assembly processes associated with DNA nanotechnology to be studied. OxDNA, our recently-developed coarse-grained DNA model, is particularly sui…
▽ More
To simulate long time and length scale processes involving DNA it is necessary to use a coarse-grained description. Here we provide an overview of different approaches to such coarse graining, focussing on those at the nucleotide level that allow the self-assembly processes associated with DNA nanotechnology to be studied. OxDNA, our recently-developed coarse-grained DNA model, is particularly suited to this task, and has opened up this field to systematic study by simulations. We illustrate some of the range of DNA nanotechnology systems to which the model is being applied, as well as the insights it can provide into fundamental biophysical properties of DNA.
△ Less
Submitted 18 August, 2013;
originally announced August 2013.
-
Characterisation of the muon beams for the Muon Ionisation Cooling Experiment
Authors:
The MICE Collaboration,
D. Adams,
D. Adey,
A. Alekou,
M. Apollonio,
R. Asfandiyarov,
J. Back,
G. Barber,
P. Barclay,
A. de Bari,
R. Bayes,
V. Bayliss,
R. Bertoni,
V. J. Blackmore,
A. Blondel,
S. Blot,
M. Bogomilov,
M. Bonesini,
C. N. Booth,
D. Bowring,
S. Boyd,
T. W. Bradshaw,
U. Bravar,
A. D. Bross,
M. Capponi
, et al. (119 additional authors not shown)
Abstract:
A novel single-particle technique to measure emittance has been developed and used to characterise seventeen different muon beams for the Muon Ionisation Cooling Experiment (MICE). The muon beams, whose mean momenta vary from 171 to 281 MeV/c, have emittances of approximately 1.5--2.3 πmm-rad horizontally and 0.6--1.0 πmm-rad vertically, a horizontal dispersion of 90--190 mm and momentum spreads o…
▽ More
A novel single-particle technique to measure emittance has been developed and used to characterise seventeen different muon beams for the Muon Ionisation Cooling Experiment (MICE). The muon beams, whose mean momenta vary from 171 to 281 MeV/c, have emittances of approximately 1.5--2.3 πmm-rad horizontally and 0.6--1.0 πmm-rad vertically, a horizontal dispersion of 90--190 mm and momentum spreads of about 25 MeV/c. There is reasonable agreement between the measured parameters of the beams and the results of simulations. The beams are found to meet the requirements of MICE.
△ Less
Submitted 11 October, 2013; v1 submitted 6 June, 2013;
originally announced June 2013.
-
Neutrinos from Stored Muons nuSTORM: Expression of Interest
Authors:
D. Adey,
S. K. Agarwalla,
C. M. Ankenbrandt,
R. Asfandiyarov,
J. J. Back,
G. Barker,
E. Baussan,
R. Bayes,
S. Bhadra,
V. Blackmore,
A. Blondel,
S. A. Bogacz,
C. Booth,
S. B. Boyd,
A. Bravar,
S. J. Brice,
A. D. Bross,
F. Cadoux,
H. Cease,
A. Cervera,
J. Cobb,
D. Colling,
L. Coney,
A. Dobbs,
J. Dobson
, et al. (84 additional authors not shown)
Abstract:
The nuSTORM facility has been designed to deliver beams of electron and muon neutrinos from the decay of a stored muon beam with a central momentum of 3.8 GeV/c and a momentum spread of 10%. The facility is unique in that it will: serve the future long- and short-baseline neutrino-oscillation programmes by providing definitive measurements of electron-neutrino- and muon-neutrino-nucleus cross sect…
▽ More
The nuSTORM facility has been designed to deliver beams of electron and muon neutrinos from the decay of a stored muon beam with a central momentum of 3.8 GeV/c and a momentum spread of 10%. The facility is unique in that it will: serve the future long- and short-baseline neutrino-oscillation programmes by providing definitive measurements of electron-neutrino- and muon-neutrino-nucleus cross sections with percent-level precision; allow searches for sterile neutrinos of exquisite sensitivity to be carried out; and constitute the essential first step in the incremental development of muon accelerators as a powerful new technique for particle physics.
Of the world's proton-accelerator laboratories, only CERN and FNAL have the infrastructure required to mount nuSTORM. Since no siting decision has yet been taken, the purpose of this Expression of Interest (EoI) is to request the resources required to: investigate in detail how nuSTORM could be implemented at CERN; and develop options for decisive European contributions to the nuSTORM facility and experimental programme wherever the facility is sited.
The EoI defines a two-year programme culminating in the delivery of a Technical Design Report.
△ Less
Submitted 7 May, 2013;
originally announced May 2013.
-
The design, construction and performance of the MICE target
Authors:
C. N. Booth,
P. Hodgson,
L. Howlett,
R. Nicholson,
E. Overton,
M. Robinson,
P. J. Smith,
M. Apollonio,
G. Barber,
A. Dobbs,
J. Leaver,
K. R. Long,
B. Shepherd,
D. Adams,
E. Capocci,
E. McCarron,
J. Tarrant
Abstract:
The pion-production target that serves the MICE Muon Beam consists of a titanium cylinder that is dipped into the halo of the ISIS proton beam. The design and construction of the MICE target system are described along with the quality-assurance procedures, electromagnetic drive and control systems, the readout electronics, and the data-acquisition system. The performance of the target is presented…
▽ More
The pion-production target that serves the MICE Muon Beam consists of a titanium cylinder that is dipped into the halo of the ISIS proton beam. The design and construction of the MICE target system are described along with the quality-assurance procedures, electromagnetic drive and control systems, the readout electronics, and the data-acquisition system. The performance of the target is presented together with the particle rates delivered to the MICE Muon Beam. Finally, the beam loss in ISIS generated by the operation of the target is evaluated as a function of the particle rate, and the operating parameters of the target are derived.
△ Less
Submitted 6 March, 2013; v1 submitted 27 November, 2012;
originally announced November 2012.