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The LHC magnet system and its status of development

CERN is preparing for the construction of a new high energy accelerator/collider, the Large Hadron Collider (LHC). This new facility will mainly consist of two superconducting magnetic beam channels, 27 km long, to be installed in the existing LEP tunnel. The magnetic system comprises about 1200 twin-aperture dipoles, 13.145 m long, with an operational field of 8.65 T, about 600 quadrupoles, 3 m long, and a very large number of other superconducting magnetic components. A general description of the system is given together with the main features of the design of the regular lattice magnets. The paper also describes the present state of the magnet R & D program. Results from short model work, as well as from full scale prototypes will be presented, including the recently tested 10 m long full-scale prototype dipole manufactured in industry.

Bona, Maurizio

Characterization of photosystem 1 chlorophyll a/b-binding apoprotein accumulation in developing soybean using type-specific antibodies

The structure and supramolecular assembly of the soybean photosystem 1 (PS 1) chlorophyll a/b-binding antenna (LHC 1) was examined. We identified the subunit composition of LHC 1 in soybean and followed the accumulation of individual subunits during light-induced assembly. We observed four LHC 1 subunits, at 23, 22, 21 and 20.5 kDa, obtained partial sequence information by amino-terminal sequence analysis, and classified the 20.5, 22, and 21 kDa subunits as being encoded by type I, II, and IV chlorophyll a/b binding protein genes, respectively. Antisera against LHC 1 subunits were used to follow the accumulation of individual subunits during the light-initiated transition from etioplast to chloroplast. Several points are noteworthy. First, monospecific antibody against the 22 kDa subunit decorated a 25 kDa peptide in etiolated tissue, which declined during maturation. This decline correlated with the light-induced appearance of mature 22 kDa peptide, suggesting a precursor/product relationship. Second, the same antibody identified a 22 kDa protein in mature corn, but not a larger band in etiolated corn, suggesting that LHC 1 accumulation is regulated differently between species before the onset of chlorophyll biosynthesis. Third, the mature 22 kDa subunit appeared somewhat later than the other LHC 1 peptides during greening, implying that this subunit is less intimately associated with the PS1 core than are the subunits appearing earlier in development.

Non-NASA Center

COLUTA: Custom 8-Channel 15-bit 40-MSPS ADC for the ATLAS Liquid Argon Calorimeter Readout

The stringent radiation-tolerance, quantization requirements, and the need for seamless integration of the on-detector readout electronics chain require the design of a full-custom analog-to-digital converter (ADC) for the 182,468 channels in the ATLAS Liquid Argon (LAr) calorimeter at the Large Hadron Collider (LHC) at CERN, as part of the High-Luminosity LHC (HL-LHC) upgrade. Each of the 8 channels in the prototype 65 nm CMOS ADC with 15-bit resolution and >68 dB signal-to-noise-and-distortion ratio (SNDR), or equivalently >11 effective number of bits (ENOB), consists of a Multiplying-DAC (MDAC) and a successive-approximation (SAR) ADC. A digital data processing unit (DDPU) calibrates and serially transmits the quantized data. Initial lab characterization of 18 chips shows a minimum SNDR of 69.5 dB at full-scale at about 5 MHz and a maximum power consumption of 1.17 W; differential non-linearity (DNL) measurements show no missing codes. Additional validation of the ADC is ongoing before approximately 70k chips can be mass-produced for the upgrade.

Rui Xu

Challenges in 21st Century Physics

We are truly fortunate to live in one of the great epochs of human discovery, a time when science is providing new visions and understanding about ourselves and the world in which we live. At last, we are beginning to explore the Universe itself. One particularly exciting area of advancement is high-energy physics where several existing concepts will be put to the test. A brief survey will be given of accomplishments in 20th Century physics. These include relativity and quantum physics which have produced breakthroughs in cosmology, astrophysics, and high-energy particle physics. The current situation is then assessed, combining the last 100 years of progress with new 21st Century challenges about unification and where to go next. Finally, the future is upon us. The next frontier in experimental high-energy physics, the Large Hadron Collider (LHC) at CERN in Geneva, is scheduled to begin coming online this year (2007). The potential for the LHC to address several of the significant problems in physics today will be discussed, as this great accelerator examines the predictions of the Standard Model of particle physics and even cosmology. New physics and new science will surely emerge and a better vision of the world will unfold.

Wilson, Thomas L.

The Ultimate Monte Carlo: Studying Cross-Sections With Cosmic Rays

The high-energy physics community has been discussing for years the need to bring together the three principal disciplines that study hadron cross-section physics - ground-based accelerators, cosmic-ray experiments in space, and air shower research. Only recently have NASA investigators begun discussing the use of space-borne cosmic-ray payloads to bridge the gap between accelerator physics and air shower work using cosmic-ray measurements. The common tool used in these three realms of high-energy hadron physics is the Monte Carlo (MC). Yet the obvious has not been considered - using a single MC for simulating the entire relativistic energy range (GeV to EeV). The task is daunting due to large uncertainties in accelerator, space, and atmospheric cascade measurements. These include inclusive versus exclusive cross-section measurements, primary composition, interaction dynamics, and possible new physics beyond the standard model. However, the discussion of a common tool or ultimate MC might be the very thing that could begin to unify these independent groups into a common purpose. The Offline ALICE concept of a Virtual MC at CERN s Large Hadron Collider (LHC) will be discussed as a rudimentary beginning of this idea, and as a possible forum for carrying it forward in the future as LHC data emerges.

Wilson, Thomas L.

Global distribution of peroxyacetyl nitrate

Peroxyacetyl nitrate (PAN) atmospheric concentration samples were collected hourly from an ocean vessel 50 mi off the continental coast traveling from Seattle to Chile in 1984. Air concentration data for PAN and light hydrocarbons (LHC) were also taken by aircraft in the same period over Wyoming and Colorado and over the eastern Pacific. The PAN concentrations were higher and more variable in the Northern Hemisphere than in the Southern Hemisphere, increased with altitude, and were higher in the winter than in summer. The summer PAN concentrations were higher in the continental troposphere than in the marine troposphere. The results show that photochemical models of the atmosphere which do not account for the reaction between nonmethane hydrocarbons and PAN will probably overestimate the abundances of NO(x) and HNO3. The collection of further PAN concentration data is recommended as a means to characterizing the moderating role of PAN in the photochemistry of the troposphere.

Singh, H. B.

Upper-Stage Flight Experiment

For propulsion applications that require that the propellants are storable for long periods, have a high density impulse, and are environmentally clean and non-toxic, the best choice is a combination of high-concentration hydrogen peroxide (High Test Peroxide, or HTP) and a liquid hydrocarbon (LHC) fuel. The HTP/LHC combination is suitable for low-cost launch vehicles, space taxi and space maneuvering vehicles, and kick stages. Orbital Sciences Corporation is under contract with the NASA Marshall Space Flight Center in cooperation with the Air Force Research Lab to design, develop and demonstrate a new low-cost liquid upper stage based on HTP and JP-8. The Upper Stage Flight Experiment (USFE) focuses on key technologies necessary to demonstrate the operation of an inherently simple propulsion system with an innovative, state-of-the-art structure. Two key low-cost vehicle elements will be demonstrated - a 10,000 lbf thrust engine and an integrated composite tank structure. The suborbital flight test of the USFE is scheduled for 2001. Preceding the flight tests are two major series of ground tests at NASA Stennis Space Center and a subscale tank development program to identify compatible composite materials and to verify their compatibility over long periods of time. The ground tests include a thrust chamber development test series and an integrated stage test. This paper summarizes the results from the first phase of the thrust chamber development tests and the results to date from the tank material compatibility tests. Engine and tank configurations that meet the goals of the program are described.

Anderson, W. E.

Proton Nonionizing Energy Loss (NIEL) for Device Applications

Nonionizing energy loss (NIEL) is a quantity that describes the rate of energy loss due to atomic displacements as a particle traverses a material. The product of the NIEL and the particle fluence (time integrated flux) gives the displacement damage energy deposition per unit mass of material. NIEL plays the same role to the displacement damage energy deposition as the stopping power to the total ionizing dose (TID). The concept of NIEL has been very useful for correlating particle induced displacement damage effects in semiconductor and optical devices. Many studies have successfully demonstrated that the degradation of semiconductor devices or optical sensors in a radiation field can be linearly correlated to the displacement damage energy, and subsequently to the NIEL deposited in the semiconductor devices or optical sensors. In addition, the NIEL concept was also useful in the study of both Si and GaAs solar cells and of high temperature superconductors, and at predicting the survivability of detectors used at the LHC at CERN. On the other hand, there are some instances where discrepancies are observed in the application of NIEL, most notably in GaAs semiconductor devices. However, NIEL is still a valuable tool, and can be used to scale damages produced by different particles and in different environments, even though this is not understood at the microscopic level.

Jun, Insoo

Update On the Status of the FLUKA Monte Carlo Transport Code*

The FLUKA Monte Carlo transport code is a well-known simulation tool in High Energy Physics. FLUKA is a dynamic tool in the sense that it is being continually updated and improved by the authors. We review the progress achieved since the last CHEP Conference on the physics models, some technical improvements to the code and some recent applications. From the point of view of the physics, improvements have been made with the extension of PEANUT to higher energies for p, n, pi, pbar/nbar and for nbars down to the lowest energies, the addition of the online capability to evolve radioactive products and get subsequent dose rates, upgrading of the treatment of EM interactions with the elimination of the need to separately prepare preprocessed files. A new coherent photon scattering model, an updated treatment of the photo-electric effect, an improved pair production model, new photon cross sections from the LLNL Cullen database have been implemented. In the field of nucleus-- nucleus interactions the electromagnetic dissociation of heavy ions has been added along with the extension of the interaction models for some nuclide pairs to energies below 100 MeV/A using the BME approach, as well as the development of an improved QMD model for intermediate energies. Both DPMJET 2.53 and 3 remain available along with rQMD 2.4 for heavy ion interactions above 100 MeV/A. Technical improvements include the ability to use parentheses in setting up the combinatorial geometry, the introduction of pre-processor directives in the input stream. a new random number generator with full 64 bit randomness, new routines for mathematical special functions (adapted from SLATEC). Finally, work is progressing on the deployment of a user-friendly GUI input interface as well as a CAD-like geometry creation and visualization tool. On the application front, FLUKA has been used to extensively evaluate the potential space radiation effects on astronauts for future deep space missions, the activation dose for beam target areas, dose calculations for radiation therapy as well as being adapted for use in the simulation of events in the ALICE detector at the LHC.

Ferrari, A.

Science on the Moon: The Wailing Wall of Space Exploration

Science on and from the Moon has important implications for expanding human knowledge and understanding, a prospect for the 21st Century that has been under discussion for at least the past 25 years. That having been said, however, there remain many issues of international versus national priorities, strategy, economy, and politics that come into play. The result is a very complex form of human behavior where science and exploration take center stage, but many other important human options are sacrificed. To renew this dialogue about the Moon, it seems we are already rushing pell-mell into it as has been done in the past. The U.S., Japan, China, India, and Russia either have sent or plan to send satellites and robotic landers there at this time. What does a return to the Moon mean, why are we doing this now, who should pay for it, and how? The only semblance of such a human enterprise seems to be the LHC currently coming online at CERN. Can it be used as a model of international collaboration rather than a sports or military event focused on national competition? Who decides and what is the human sacrifice? There are compelling arguments for establishing science on the Moon as one of the primary goals for returning to the Moon and venturing beyond. A number of science endeavors will be summarized, beyond lunar and planetary science per se. These include fundamental physics experiments that are background-limited by the Earth's magnetic dipole moment and noise produced by its atmosphere and seismic interior. The Moon is an excellent platform for some forms of astronomy. Other candidate Moon-based experiments vary from neutrino and gravitational wave astronomy, particle astrophysics, and cosmic-ray calorimeters, to space physics and fundamental physics such as proton decay. The list goes on and includes placing humans in a hostile environment to study the long-term effects of space weather. The list is long, and even newer ideas will come from this COSPAR conference. However, whatever the list the issue of cooperation and binding collaboration remains. As observers of Moon and other space enterprises, we all know that a room full of 60 scientists will not agree on much of anything and there will probably be 60! please for more funding. People have special interests and little common sense (e.g., conflict between NSF- and NASA-funding roadmaps). Scientists are no exception. Nevertheless, CERN has done it on Earth! Can we do the same on the Moon? Some of the present generation of proposals for science from and on the Moon, plus new ones, will witness a place in space exploration's future. It is clear, however, that the world has not thought this through adequately, except for talk about an international space federation whatever that is. An outpost on the Moon with humans permanently living there much like Antarctica on Earth may be in our future. However, such planning is our collective international responsibility and not that of special-interest investigators from individual nations unless they intend to pay for it.

Wilson, Thomas

The Cosmic Ray Electron Excess

This slide presentation reviews the possible sources for the apparent excess of Cosmic Ray Electrons. The presentation reviews the Advanced Thin Ionization Calorimeter (ATIC) instrument, the various parts, how cosmic ray electrons are measured, and shows graphs that review the results of the ATIC instrument measurement. A review of Cosmic Ray Electrons models is explored, along with the source candidates. Scenarios for the excess are reviewed: Supernova remnants (SNR) Pulsar Wind nebulae, or Microquasars. Each of these has some problem that mitigates the argument. The last possibility discussed is Dark Matter. The Anti-Matter Exploration and Light-nuclei Astrophysics (PAMELA) mission is to search for evidence of annihilations of dark matter particles, to search for anti-nuclei, to test cosmic-ray propagation models, and to measure electron and positron spectra. There are slides explaining the results of Pamela and how to compare these with those of the ATIC experiment. Dark matter annihilation is then reviewed, which represent two types of dark matter: Neutralinos, and kaluza-Kline (KK) particles, which are next explained. The future astrophysical measurements, those from GLAST LAT, the Alpha Magnetic Spectrometer (AMS), and HEPCAT are reviewed, in light of assisting in finding an explanation for the observed excess. Also the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) could help by revealing if there are extra dimensions.

Chang, J.

Science Objectives of the JEM EUSO Mission on International Space Station

JEM-EUSO space observatory is planned with a very large exposure factor which will exceed the critical exposure factor required for observing the most of the sources within the propagational horizon of about one hundred Mpc. The main science objective of JEM-EUSO is the source-identifying astronomy in particle channel with extremey-high-energy particles. Quasi-linear tracking of the source objects through galactic magnetic field should become feasible at energy > 10(exp 20) eV for all-sky. The individual GZK profile in high statistics experiments should differ from source to source due to different distance unless Lorentz invariance is somehow limited. hi addition, JEM-EUSO has three exploratory test observations: (i), extremely high energy neutrinos beginning at E > 10(exp 19) eV: neutrinos as being expected to have a slowly increasing cross section in the Standard Model, and in particular, hundreds of times more in the extra-dimension models. (ii). fundamental physics at extreme Super LHC (Large Hadronic Collider) energies with the hierarchical unified energy much below the GUT scale, and (iii). global atmospheric observation, including large-scale and local plasma discharges, night-glow, meteorites, and others..

Takahashi, Yoshiyuki

Status of the Space Radiation Monte Carlos Simulation Based on FLUKA and ROOT

The NASA-funded project reported on at the first IWSSRR in Arona to develop a Monte-Carlo simulation program for use in simulating the space radiation environment based on the FLUKA and ROOT codes is well into its second year of development, and considerable progress has been made. The general tasks required to achieve the final goals include the addition of heavy-ion interactions into the FLUKA code and the provision of a ROOT-based interface to FLUKA. The most significant progress to date includes the incorporation of the DPMJET event generator code within FLUKA to handle heavy-ion interactions for incident projectile energies greater than 3GeV/A. The ongoing effort intends to extend the treatment of these interactions down to 10 MeV, and at present two alternative approaches are being explored. The ROOT interface is being pursued in conjunction with the CERN LHC ALICE software team through an adaptation of their existing AliROOT software. As a check on the validity of the code, a simulation of the recent data taken by the ATIC experiment is underway.

Andersen, Victor

Limits on Large Extra Dimensions Based on Observations of Neutron Stars with the Fermi-LAT

We present limits for the compactification scale in the theory of Large Extra Dimensions (LED) proposed by Arkani-Hamed, Dimopoulos, and Dvali. We use 11 months of data from the Fermi Large Area Telescope (Fermi-LAT) to set gamma ray flux limits for 6 gamma-ray faint neutron stars (NS). To set limits on LED we use the model of Hannestad and Raffelt (HR) that calculates the Kaluza-Klein (KK) graviton production in supernova cores and the large fraction subsequently gravitationally bound around the resulting NS. The predicted decay of the bound KK gravitons to should contribute to the flux from NSs. Considering 2 to 7 extra dimensions of the same size in the context of the HR model, we use Monte Carlo techniques to calculate the expected differential flux of gamma-rays arising from these KK gravitons, including the effects of the age of the NS, graviton orbit, and absorption of gamma-rays in the magnetosphere of the NS. We compare our Monte Carlo-based differential flux to the experimental differential flux using maximum likelihood techniques to obtain our limits on LED. Our limits are more restrictive than past EGRET-based optimistic limits that do not include these important corrections. Additionally, our limits are more stringent than LHC based limits for 3 or fewer LED, and comparable for 4 LED. We conclude that if the effective Planck scale is around a TeV, then for 2 or 3 LED the compactification topology must be more complicated than a torus.

Ferrara, E. C.

AstroPix: ATLAS-Inspired Silicon Pixels for Future Space-Based Gamma-ray Telescopes

Space-based gamma-ray telescopes such as the Fermi Large Area Telescope have used single sided silicon strip detectors to measure the position of incident gamma-rays with high resolution. At lower energies, two dimensional position information within a single detector is required. This talk investigates the use of monolithic CMOS active pixel silicon sensors –AstroPix – as a novel technology for use in future gamma-ray telescopes. Based upon detectors designed for use in the ATLAS detector at the LHC, AstroPix has the potential to maintain the high energy and angular resolution required of a medium-energy gamma-ray telescope while reducing noise with the dual detection and readout capabilities of a CMOS chip. The status of AstroPix development and testing, as well as outlook for application in future telescopes such as the proposed medium-energy gamma-ray telescope AMEGO-X, will be presented.

Amanda L. Steinhebel