| 1. |
- Millar, Alexander J., et al.
(författare)
-
Searching for dark matter with plasma haloscopes
- 2023
-
Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 107:5
-
Tidskriftsartikel (refereegranskat)abstract
- We summarize the recent progress of the Axion Longitudinal Plasma Haloscope (ALPHA) Consortium, a new experimental collaboration to build a plasma haloscope to search for axions and dark photons. The plasma haloscope is a novel method for the detection of the resonant conversion of light dark matter to photons. ALPHA will be sensitive to QCD axions over almost a decade of parameter space, potentially discovering dark matter and resolving the strong CP problem. Unlike traditional cavity haloscopes, which are generally limited in volume by the Compton wavelength of the dark matter, plasma haloscopes use a wire metamaterial to create a tuneable artificial plasma frequency, decoupling the wavelength of light from the Compton wavelength and allowing for much stronger signals. We develop the theoretical foundations of plasma haloscopes and discuss recent experimental progress. Finally, we outline a baseline design for ALPHA and show that a full-scale experiment could discover QCD axions over almost a decade of parameter space.
|
|
| 2. |
- Li, Han, et al.
(författare)
-
RF Performance of the spoke prototype cryomodule for ESS
- 2019
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The European spallation source (ESS), as a world-class high power proton accelerator facility, will be the first one to adopt 26 double spoke resonators (DSR) at its low energy section. As a new superconducting accelerating structure, these DSRs are therefore considered as a key technology and challenge of the whole project. They will be the first D SRs in the world to be commissionedfor a high power proton accelerator. As a milestone, the first DSR prototype cryomodule for ESS project was successfully tested at the FREIA Laboratory. In this qualification of the prototype cryomodule, the whole chain of RF station, RF distribution, fundamental power coupler (FPC), DSRs, cold tuning system (CTS) and low level radio frequency (LLRF) system, as well as the testing procedure have been verified on preparation for the industrialized cryomodules. Both cavities in the prototype cryomodule achieved nominal accelerating gradient, with the maximum gradient of 15 MV/m and 10.5 MV/m for cavity 1 and cavity 2 respectively. Based on the calorimetrical method, the dynamic heat load measurement showed that the cavity power consumption is around 0.5 W and therefore the intrinsic quality factor is consistent with the vertical test. This report presents the test configuration, RF conditioning history and first high power performance of this cryomodule.
|
|
| 3. |
- Longuevergne, D., et al.
(författare)
-
Impact of geometry on the magnetic flux trapping of superconducting accelerating cavities
- 2021
-
Ingår i: Physical Review Accelerators and Beams. - : American Physical Society. - 2469-9888. ; 24:8
-
Tidskriftsartikel (refereegranskat)abstract
- Controlling trapped magnetic flux in superconducting radio frequency (rf) cavities is of crucial importance in modern accelerator projects. In order to study flux trapping efficiency and sensitivity of surface resistance, dedicated experiments have been carried out on different types of low-fl superconducting accelerating cavities. Even under almost full trapping conditions, we found that the measured magnetic sensitivities of these cavity geometries were significantly lower than the theoretical values predicted by commonly used models based on local material properties. This must be resolved by taking account of geometrical effects of flux trapping and flux oscillation under rf surface current in such cavity shape. In this paper, we propose a new approach to convolute the influence of geometries. We point out a puzzling contradiction between sample measurements and recent cavity experiments, which leads to two different hypotheses to simulate oscillating flux trapped in the cavity surface. A critical reconsideration of flux oscillation by the rf Lorentz force, compared with temperature mapping studies in elliptical cavities, favored the results of previous sample measurements, which suggested preferential flux trapping of normal component to the cavity inner surface. Based on this observation, we builded a new model to our experimental results and the discrepancy between old theory and data were resolved.
|
|
| 4. |
- Miyazaki, Akira, 1986-
(författare)
-
Dark matter emission from high-power millimeter waves and potential detection by coherent system
- 2021
-
Ingår i: 2021 46th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THZ). - : Institute of Electrical and Electronics Engineers (IEEE). - 9781728194240
-
Konferensbidrag (refereegranskat)abstract
- The dark photon, one of the candidates of dark matter, can be generated from high-power millimeter waves. This paper points out possible emission of dark photons from waveguide structures in high-power microwave infrastructure and suggests potential detection of such dark photon signal with a coherent circuit scheme.
|
|
| 5. |
- Miyazaki, Akira, 1986-, et al.
(författare)
-
Dark photon search with a gyrotron and a transition edge sensor
- 2020
-
Ingår i: 2020 45th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz). - 9781728166209 - 9781728166216
-
Konferensbidrag (refereegranskat)abstract
- A dark photon, one of the candidates of light dark matter, will be searched around 0.1 meV range by using a gyrotron. The use of a Transition Edge Sensor is the key of this experiment and the expected result is promising. This search will pave a way to future axion search using similar instruments.
|
|
| 6. |
- Miyazaki, Akira, 1986-, et al.
(författare)
-
First cold test of a crab cavity at the GERSEMI cryostat for the HL-LHC project
- 2020
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- We tested the prototype DQW cavity in GERSEMI vertical test stand in FREIA. The performance metthe spec ification , and our experimental procedure and infrastructure are qualified for testing crab cavitiesi n the HL LHC project. This was the critic al milestone in the project and it also opens a newopportunity for testing superconducting cavities in FREIA.
|
|
| 7. |
- Miyazaki, Akira, 1986-, et al.
(författare)
-
Millimeter-Wave WISP Search with Coherent Light-Shining-Through-a-Wall Toward the STAX Project
- 2024
-
Ingår i: Annalen der Physik. - : John Wiley & Sons. - 0003-3804 .- 1521-3889. ; 536:1
-
Tidskriftsartikel (refereegranskat)abstract
- A dark photon is one of the simplest extensions of the Standard Model of particle physics and can be a dark matter candidate. Dark photons kinetically mix with ordinary photons. The mass range from 10(-4) to 10(-3) eV of such dark photons is underconstrained by laboratory-based experiments and a new search is therefore motivated. In this mass range, dark photons behave like waves rather than particles and the corresponding electromagnetic waves are in the millimeter-wave range. The technical difficulties of the millimeter waves have prevented so far dark photon experiments in this mass range. The use of coherent millimeter waves to search for dark photons in a Light-Shining-through-a-Wall (LSW) experiment is proposed. The merits and limitations of coherent wave detection are clarified and the potential of single photon sensors at microwaves is investigated. Development of millimeter-wave technology is not only limited to dark photons. Technically, an experiment for dark photons by using electromagnetic waves resembles that for axions, another light dark matter candidate, with static magnetic fields. This paper represents an essential step toward axion LSW in the millimeter-wave range (Sub-THz-AXion experiment; STAX) as a potential successor of an on-going experiment in infrared.
|
|
| 8. |
- Miyazaki, Akira, 1986-
(författare)
-
Progress report for the second cold test of a crab cavity for the HL-LHC project
- 2021
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Weare preparing to test a prototype crab cavity in GERSEMI vertical test stand in the FREIA laboratory .After the first experiment in 2020, several issues were pointe d out and further investigation andimprovements were performed . Th e issue in beam vacuum and arcing at the RF feedthrough were solvedby replacing the problematic components identified by some experiments . M agnetic field mapping wasperformed to address potential magnetization of the cryostat after the first test of superconductingmagnet in the same cryostat . We also report a new activity in a cleanroom to fix an issue of the pick upantenna which occurred during transport from Geneva to Uppsala
|
|
| 9. |
- Miyazaki, Akira, 1986-, et al.
(författare)
-
Proof-of-principle of the ultra-narrowband detection scheme at 30 GHz toward weakly interacting slim particle search
- 2021
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A coherent detection scheme was tested for dark photons and axion search with millimeter waves. It was shown that relative bandwidth of 169 μHz can be achieved at the center frequency of 30 GHz by commercial equipment. This is in principle a lock-in amplifier at 30 GHz. With a low noise amplifier, thermal noise can be reduced down to 1.36 X 10-24 with one and half hours data taking and the expected signal was locked within one bin of 169 μHz resolution bandwidth by using the standard 10 MHz reference line. This will lead to a new search of dark photons in the mass range, which is complementary to any previous experiments and a future upgrade project of ALPS-II. Although a fully quantum mechanical argument will be necessary to quantify the ultimate limit of this coherent detection scheme, the use of a state-of-the-art phase-locked gyrotron and superconducting quantum sensors would lead to further improvement of millimeter-wave dark photon and axion searches.
|
|
| 10. |
- Miyazaki, Akira, 1986-
(författare)
-
Radiation shield design for the vertical cryostat GERSEMI
- 2019
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- We designed a radiation shield for the vertical cryostat at FREIA. The design is dedicated to a prototype crab cavity for the High-Lumi LHC project, and is normalized with an experimental radiation dose measured at CERN in the most contaminated case ever observed. The predicted dose is below 10 T outside the normal concrete shield made of 30 cm thick wall and 60 thick roof.
|
|
| 11. |
|
|
| 12. |
- Miyazaki, Akira, 1986-, et al.
(författare)
-
Ultra narrowband detection scheme for dark photon / axion around 30 GHz
- 2022
-
Ingår i: 2022 47th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz 2022). - : Institute of Electrical and Electronics Engineers (IEEE). - 9781728194271 - 9781728194288 ; , s. 1-1
-
Konferensbidrag (refereegranskat)abstract
- We demonstrated that ultra narrowband filtering at 30 GHz dramatically enhances the signal-to-noise ratio to search for dark matter candidates which couple to millimeter waves. A coherent signal relatively locked between a synthesizer and a signal analyzer can be clearly distinguished from incoherent blackbody radiation after real time FFT over a long period. We propose a novel experiment for studying dark matter candidates.
|
|
| 13. |
- Ruber, Roger, et al.
(författare)
-
Accelerator development at the FREIA Laboratory
- 2021
-
Ingår i: Journal of Instrumentation. - : Institute of Physics Publishing (IOPP). - 1748-0221. ; 16:7
-
Tidskriftsartikel (refereegranskat)abstract
- The FREIA Laboratory at Uppsala University focuses on superconducting technology and accelerator development. It actively supports the development of the European Spallation Source, CERN, and MAX IV, among others. FREIA has developed test facilities for superconducting accelerator technology such as a double-cavity horizontal test cryostat, a vertical cryostat with a novel magnetic field compensation scheme, and a test stand for short cryomodules. Accelerating cavities have been tested in the horizontal cryostat, crab-cavities cavities in the vertical cryostat, and cryomodules for ESS on the cryomodule test stand. High power radio-frequency amplifier prototypes based on vacuum tube technology were developed for driving spoke cavities. Solid-state amplifiers and power combiners are under development for future projects. We present the status of the FREIA Laboratory complemented with results of recent projects and future prospects.
|
|
| 14. |
- Santiago-Kern, Rocio, et al.
(författare)
-
Cryogenic Performance of the Spoke Prototype Cryomodule for ESS
- 2019
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report gives an account of all the cryogenic tests performed on the prototype spoke cryomodule, which housed Romea (cavity 1) and Giulietta (cavity 2) with all their ancillary equipment, such as static and dynamic heat loads under different circumstances.
|
|
