Middle Drum Research Articles

Cosmic ray mass composition measurement with the TALE hybrid detector

The Telescope Array (TA) located in the State of Utah in the US is the largest ultra-high energy cosmic rays observatory in the northern hemisphere. The Telescope Array Low-energy Extension (TALE) detector was constructed to study the transition of cosmic rays from Galactic to extra-galactic origin. The TALE detector consists of a Fluorescence Detector (FD) station with 10 high elevation telescopes located at the TA Middle Drum FD Station (itself made up of 14 FD telescopes), and a Surface Detector (SD) array made up of 80 scintillation counters, including 40 with 400 m spacing and 40 with 600 m spacing. We have continued stable observation with hybrid mode since 2017. In this contribution, we present the latest result of the cosmic ray mass composition measurement using almost 4 years of TALE hybrid data.

Study on the Effect of Isotropic Initial Stress on the Anchoring Performance of Self‐Expanding Bolts

In order to study the anchoring performance of a new type of self‐expanding, high‐strength, precompression anchoring technology with a large amount of expansion agent (ω ≥ 5) cement slurry as anchoring solids under confined surrounding rock conditions, a rock mass anchoring device and methods that simulate in situ stress are developed, and real‐time monitoring of expansion stress and anchor pull‐out tests are carried out. The results show that the internal interface stress has a loss effect over time, and the stress loss value shows a linear increase trend with the dosage, but the loss rate shows a linear decreasing relationship with the dosage. This paper defines the coordinated additional stress and obtains its temporal and spatial evolution law in the rock mass. It is pointed out that there is a lag time difference between the peak of internal interface stress and the peak of coordinated additional stress, explaining its mechanical mechanism from the perspective of stress transfer. The strong restraint of the sealing section of the anchor hole causes the anchor solid to form a “shuttle‐shaped” microexpanded head with thin ends and a middle drum under the expansion stress. During the drawing process, the microexpanded head is “stuck” in the anchor hole and moves upward to form the unique “load platform effect” of the anchoring system. And the mechanical mechanism diagram of this effect is obtained. It is pointed out that this effect can greatly improve the ductility of the anchoring system and the ultimate energy consumption value of damage. A prediction model for the ultimate pull‐out force of self‐expanding bolts is established. It is pointed out that the initial confining stress value has an exponential effect on the ultimate pull‐out force. It shows that the surrounding rock with strong confinement constraints can greatly increase the ultimate pull‐out resistance of the bolt. The self‐expanding strengthening coefficient λ and the surrounding rock stress influence coefficient k are introduced, the bolt interface mechanics formula and energy equation of the self‐expanding anchor system are established, and the feasibility of the formula is verified by the calculation example. It is concluded that the ultimate pull‐out resistance of the anchorage with ω = 30 is increased by 3.38 times compared with the ordinary anchorage under the initial confining stress condition of 0.7 MPa, the prepeak displacement of the bolt is increased by 2.08 times, and the prepeak energy consumption of the anchoring system is increased by 7.34 times. The cost only increased by 0.023% based on the literature example.

A methodology for designing cutting drum of surface miner to achieve production of desired chip size

The size of coal chips, produced during coal cutting operations, is of prime importance from the viewpoint of feed size desired by power plants. Proper chip size in cutting can eliminate primary crushing and in-turn save energy. Achieving a designated size of chip is intimately linked with the drum design inter alia the wrap angle, line spacing of picks and pick size. Operating parameters namely cutting speed and drum speed also influence the output. Considering the increased need to produce a sized product for cost-effective mining, a design methodology was developed to achieve a required chip size for surface miners with a middle drum configuration. Various pick, drum and operational parameters were taken into account for the development of drum design, namely drum width, drum diameter, pick size, clearance angle, rake angle, cutting angle, lacing pattern, angle of wrap, depth of cut, indented depth of cut and pick spacing. Limiting factors for drum design such as the number of picks, pick temperature, strength of pick, depth of cut and dust generation were discussed. A new drum configuration for achieving 100 mm chip size was validated which showed close agreement with the output produced using 2200SM model surface miner.

NICHE: Air-Cherenkov observation at the TA site

The Non-Imaging CHErenkov (NICHE) Array has been deployed at the Telescope Array Middle Drum site, and has been collecting data. We see many coincidences with TALE fluorescence mirror events, establishing hybrid imaging/non-imaging air-Cherenkov observation of cosmic ray air showers. We have verified the TALE Profile-Constrained Geometry Fit of Cherenkov events at the 3° level. We have performed hybrid timing fits between NICHE and TALE and have established that the growth in the FWHM of the NICHE signal with the distance of the shower core depends on the height of the shower maximum.

Publisher’s Note: Measurement of the proton-air cross section with Telescope Array’s Middle Drum detector and surface array in hybrid mode [Phys. Rev. D92, 032007 (2015)

Publisher’s Note: Measurement of the proton-air cross section with Telescope Array’s Middle Drum detector and surface array in hybrid mode [Phys. Rev. D<b>92</b>, 032007 (2015)

Measurement of the proton-air cross section with Telescope Array’s Middle Drum detector and surface array in hybrid mode

In this work we are reporting on the measurement of the proton-air inelastic cross section $\sigma^{\rm inel}_{\rm p-air}$ using the Telescope Array (TA) detector. Based on the measurement of the $\sigma^{\rm inel}_{\rm p-air}$ the proton-proton cross section $\sigma_{\rm p-p}$ value is also determined at $\sqrt{s} = 95_{-8}^{+5}$ TeV. Detecting cosmic ray events at ultra high energies with Telescope Array enables us to study this fundamental parameter that we are otherwise unable to access with particle accelerators. The data used in this report is the hybrid events observed by the Middle Drum fluorescence detector together with the surface array detector collected over five years. The value of the $\sigma^{\rm inel}_{\rm p-air}$ is found to be equal to $567.0 \pm 70.5 [{\rm Stat.}] ^{+29}_{-25} [{\rm Sys.}]$ mb. The total proton-proton cross section is subsequently inferred from Glauber Formalism and Block, Halzen and Stanev QCD inspired fit and is found to be equal to $170_{-44}^{+48} [{\rm Stat.}] _{-17}^{+19} [{\rm Sys.}] $mb.

The hybrid energy spectrum of Telescope Array’s Middle Drum Detector and surface array

The Telescope Array experiment studies ultra high energy cosmic rays using a hybrid detector. Fluorescence telescopes measure the longitudinal development of the extensive air shower generated when a primary cosmic ray particle interacts with the atmosphere. Meanwhile, scintillator detectors measure the lateral distribution of secondary shower particles that hit the ground. The Middle Drum (MD) fluorescence telescope station consists of 14 telescopes from the High Resolution Fly’s Eye (HiRes) experiment, providing a direct link back to the HiRes measurements. Using the scintillator detector data in conjunction with the telescope data improves the geometrical reconstruction of the showers significantly, and hence, provides a more accurate reconstruction of the energy of the primary particle. The Middle Drum hybrid spectrum is presented and compared to that measured by the Middle Drum station in monocular mode. Further, the hybrid data establishes a link between the Middle Drum data and the surface array. A comparison between the Middle Drum hybrid energy spectrum and scintillator Surface Detector (SD) spectrum is also shown.

Study of Ultra-High Energy Cosmic Ray composition using Telescope Array’s Middle Drum detector and surface array in hybrid mode

Previous measurements of the composition of Ultra-High Energy Cosmic Rays (UHECRs) made by the High Resolution Fly’s Eye (HiRes) and Pierre Auger Observatory (PAO) are seemingly contradictory, but utilize different detection methods, as HiRes was a stereo detector and PAO is a hybrid detector. The five year Telescope Array (TA) Middle Drum hybrid composition measurement is similar in some, but not all, respects in methodology to PAO, and good agreement is evident between data and a light, largely protonic, composition when comparing the measurements to predictions obtained with the QGSJetII-03 and QGSJet-01c models. These models are also in agreement with previous HiRes stereo measurements, confirming the equivalence of the stereo and hybrid methods. The data is incompatible with a pure iron composition, for all models examined, over the available range of energies. The elongation rate and mean values of Xmax are in good agreement with Pierre Auger Observatory data. This analysis is presented using two methods: data cuts using simple geometrical variables and a new pattern recognition technique.

The Telescope Array Middle Drum fluorescence detector simulation on GPUs

In recent years, the Graphics Processing Unit (GPU) has been recognized and widely used as an accelerator for many scientific calculations. In general, problems amenable to parallelization are ones that benefit most from the use of GPUs. The Monte Carlo simulation of fluorescence detector response to air showers presents many opportunities for parallelization. In this paper we report on a Monte Carlo program used for the simulation of the Telescope Array Fluorescence Detector located at the Middle Drum site which uses GPU acceleration. All of the physics simulation from shower development, light production and atmospheric attenuation, as well as, the realistic detector optics and electronics simulations are done on the GPU. A detailed description of the code implementation is given, and results on the accuracy and performance of the simulation are presented as well. Improvements in computational throughput in excess of 50× are reported and the accuracy of the results is on par with the CPU implementation of the simulation.

The energy spectrum of ultra-high-energy cosmic rays measured by the Telescope Array FADC fluorescence detectors in monocular mode

We present a measurement of the energy spectrum of ultra-high-energy cosmic rays performed by the Telescope Array experiment using monocular observations from its two new FADC-based fluorescence detectors. After a short description of the experiment, we describe the data analysis and event reconstruction procedures. Since the aperture of the experiment must be calculated by Monte Carlo simulation, we describe this calculation and the comparisons of simulated and real data used to verify the validity of the aperture calculation. Finally, we present the energy spectrum calculated from the merged monocular data sets of the two FADC-based detectors, and also the combination of this merged spectrum with an independent, previously published monocular spectrum measurement performed by Telescope Array’s third fluorescence detector [T. Abu-Zayyad et al., The energy spectrum of Telescope Array’s middle drum detector and the direct comparison to the high resolution fly’s eye experiment, Astroparticle Physics 39 (2012) 109-119, http://dx.doi.org/10.1016/j.astropartphys.2012.05.012, Available from: <arXiv:1202.5141>]. This combined spectrum corroborates the recently published Telescope Array surface detector spectrum [T. Abu-Zayyad, et al., The cosmic-ray energy spectrum observed with the surface detector of the Telescope Array experiment, ApJ 768 (2013) L1, http://dx.doi.org/10.1088/2041-8205/768/1/L1, Available from: <arXiv:1205.5067>] with independent systematic uncertainties.

Middle school drum ensemble: an unlikely experience in classroom democracy

Though music has a long and successful history within education, it is often one of the first sacrificial lambs when school budgets tighten. Over the course of an academic year, a documentary film sought to tell the story of an American middle school drum ensemble. The context of this group provided an ideal way to examine the nature of student participation in extra-curricular activities and how those activities provide the kinds of challenges and experiences that lead to satisfaction and self-efficacy in students. Most of these students have never played an instrument, and the group represents a cross section for every type of social group within this school setting. The tone taken by the teacher is one of democratic equalities. Students know and experience this, and it is one of many reasons why the group has continually grown over the short time it has been at this school.

Recent results of the energy spectrum and mass composition from Telescope Array Fluorescence Detector

The Telescope Array experiment is the largest hybrid detector to observe Ultra-High Energy Cosmic Rays in the northern hemisphere. The observation started in November 2007 for Fluorescence Detector (FD) and in March 2008 for Surface Detectors (SD). Here, we present the preliminary results of the energy spectrum and mass composition of the UHECRs measured by the FD and hybrid technique from the Telescope Array three year observations. The energy spectrum measured by the Middle Drum FD station, which is the refurbished HiRes-I detector is consistent with the results from HiRes. The energy spectrum with the two newly constructed FDs and SD is also in good agreement with the result from HiRes, especially for the energy scale. The mass composition study with the slant depth of the maximum shower development (Xmax) is obtained by using the stereo and hybrid analysis. The result of the mass composition is consistent with the proton prediction.

The energy spectrum of Telescope Array’s Middle Drum detector and the direct comparison to the High Resolution Fly’s Eye experiment

The Telescope Array’s Middle Drum fluorescence detector was instrumented with telescopes refurbished from the High Resolution Fly’s Eye’s HiRes-1 site. The data observed by Middle Drum in monocular mode was analyzed via the HiRes-1 profile-constrained geometry reconstruction technique and utilized the same calibration techniques enabling a direct comparison of the energy spectra and energy scales between the two experiments. The spectrum measured using the Middle Drum telescopes is based on a three-year exposure collected between December 16, 2007 and December 16, 2010. The calculated difference between the spectrum of the Middle Drum observations and the published spectrum obtained by the data collected by the HiRes-1 site allows the HiRes-1 energy scale to be transferred to Middle Drum. The HiRes energy scale is applied to the entire Telescope Array by making a comparison between Middle Drum monocular events and hybrid events that triggered both Middle Drum and the Telescope Array’s scintillator ground array.

Commander of the Cool: Translating the Art of an African Woman Excerpts from Robert Farris Thompson’s Final Keynote Address

Commander of the Cool: Translating the Art of an African Woman Excerpts from Robert Farris Thompson’s Final Keynote Address Robert Farris Thompson (bio) Delivered Saturday, October 15, 2011, at the Menil Collection, Houston, TX “What is translation? Why don’t we start with bad translation? Bad translation is when John Wayne says, “Give me a shot of red eye,” and it comes out, “Dubonnet s’il vous plait.” Another bad translation: when John Wayne says, “Drinks all on the house. I’m feelin’ loose as a goose.” Subtitle in Zurich: “Cognac fur alle.” What an elegant cowboy! Imagine the late and great Humphrey Bogart kissing the forever great Lauren Bacall. He pushes her against the wall and they kiss, languorously. Lauren says, “I’ve never been kissed like that in my life.” Spanish subtitle: “Muchísimas gracias.” So, how do we avoid such catastrophes? The German theorist Walter Benjamin has an answer for you. He says, “You cannot translate anything—French into German, Japanese into Mandarin—unless you love the other language as much as your own.” And I’m here to tell you that I love Yoruba, maybe even more than English, who knows? Imagine yourself coming in from the Eighth Galaxy and your mission is: “Check the planet. Send us back a message. Is there life?” You send a zap to Paris and it picks up by luck John Coltrane on recording. Then you hit Rio [samba drumming sounds]. Then you hit the South Bronx: Mambo! And so forth. So you send back to Eighth Galaxy: “Your Highness, I have probed the planet. There is definitely life and to judge from the sounds I am getting: they baaaad!” The point being the extra-terrestrial listened to so many forms of black music that he’s even beginning to talk black. The big triumph is that the airwaves of our planet belong to black people. No matter where you are you’ll pick up black music. Or maybe you are in Manila and you pick up: boom-chi-boom-chick. That is, of course, Habanera sped up to become Reggaeton. Wherever you are, what’s the secret of the black conquest of the airwaves? They have something that no other musical tradition has and that’s multiple meter: 4/4, plus 2/4, plus 6/8, plus 12 and a half, plus whatever you got. Multiple meter—you can see it happening centuries ago in the fifteen hundreds in Benin [pointing at an image] . . . you can see there is one being struck with the hands in the middle drum, you can see a person is striking a counter beat with a stick on the side of the drum, and then you got another drummer. At least three different beats. Cut to Brazil today in 2011, and you’ll see the same combination of drums, each [End Page 999] one with a different texture or different metrical pattern. Multiple meter. That’s one of the powerhouses behind the black conquest. And that conquest leads to the great invention of the classical music of our nation: Jazz. What do you do under drum fire? How can you function when you are bombarded by multiple meter? And that leads us to something else here that we have to translate: cool. That is to say, a collectiveness of mind. You are under drum fire, in which you keep your mental gyroscope and what you do is internalize the beat. You’re no longer afraid of dancing because you are a beat of your own. If there’s anything that black people have taught me is that people are art. Even to me Payton, the great running back who invented the stutter-step, or brought the stutter-step into NFL football, he’s a work of art, just as much as Malcolm X or John Coltrane. Just as much as “Lady Day,” AKA Billie Holiday. Diaspora to me is a magical word. It means the impossible. It means that you recreate Africa right in the middle of the USA. [End Page 1000] Robert Farris Thompson Robert Farris Thompson is The Colonel John Trumbull Professor of the History of African & African American Art at...

P.2.d.013 Cannabinoid CB1 receptor expression and G protein coupling in a genetic model of depression

We present a measurement of the energy spectrum of ultra-high-energy cosmic rays performed by the Telescope Array experiment using monocular observations from its two new FADC-based fluorescence detectors. After a short description of the experiment, we describe the data analysis and event reconstruction procedures. Since the aperture of the experiment must be calculated by Monte Carlo simulation, we describe this calculation and the comparisons of simulated and real data used to verify the validity of the aperture calculation. Finally, we present the energy spectrum calculated from the merged monocular data sets of the two FADC-based detectors, and also the combination of this merged spectrum with an independent, previously published monocular spectrum measurement performed by Telescope Array’s third fluorescence detector [T. Abu-Zayyad et al., The energy spectrum of Telescope Array’s middle drum detector and the direct comparison to the high resolution fly’s eye experiment, Astroparticle Physics 39 (2012) 109-119, http://dx.doi.org/10.1016/j.astropartphys.2012.05.012, Available from: <arXiv:1202.5141>]. This combined spectrum corroborates the recently published Telescope Array surface detector spectrum [T. Abu-Zayyad, et al., The cosmic-ray energy spectrum observed with the surface detector of the Telescope Array experiment, ApJ 768 (2013) L1, http://dx.doi.org/10.1088/2041-8205/768/1/L1, Available from: <arXiv:1205.5067>] with independent systematic uncertainties.

First results from the Telescope Array

The Telescope Array Project is a successor to the High Resolution Flyʼs Eye (HiRes) and AGASA (Akeno Giant Air Shower Array) experiments. It is the largest ultra high energy cosmic ray experiment in the northern hemisphere. The Telescope Array observatory has been collecting data since 2008 using a hybrid of fluorescence telescopes and scintillator surface detectors. Some of the first results from the experiment are presented including the monocular spectrum from the Middle Drum fluorescence site and the spectrum from the scintillator array. These are in good agreement with the spectrum from the High Resolution Flyʼs Eye. In addition, a first pass at a composition measurement is made and indicates a predominantly light composition in the 10 19 eV region. Finally, some of the ongoing work of the group is presented including a novel technique for an end to end calibration of the telescopes involving a 40 MeV linear accelerator.

Updated analysis of the Telescope Array's Middle Drum (MD) fluorescence detector data

Updated analysis of the Telescope Array's Middle Drum (MD) fluorescence detector data