Expressions of Intent for IPY 2007-2008 Activities

Expression of Interest Details

PROPOSAL INFORMATION

Bolometric Interferometric Measurements of B-mode polarization in the Cosmic Microwave Background.  (BRAIN:Background Radiation Interferometer)

Outline
BRAIN/ClOVER is a project aimed to the study of the Early Universe and of its evolution. In particular it focuses on the measure of the Gravitational Waves Background that would be generated in the very early Universe during the epoch of Inflation. Inflation is a phase of the evolution of the Universe characterized by an accelerated expansion of the metrical space that ends 10-34 seconds after the Big Bang. Inflation theory predicts that this expansion was propelled by a quantum-mechanical energy of the vacuum. Relics of those quantum fluctuations are left in a background of Gravitational waves. These waves leave an imprint on the polarization of the Cosmic Microwave Background (CMB) radiation with a peculiar symmetry property. The component of the CMB with such a property is called the B-mode of the CMB polarization. The detection of the gravitational waves via the B-modes permits investigation of the very first instants of the history of the Universe, and a direct measurements of the Energy scale of the inflationary era. This is of utmost importance also for Fundamental Physics, testing Physics at energy much higher than any foreseeable particle accelerator.The extremely low intensity of the signal to be measured and the number of potential systematic effects make the experimental effort particularly hard. Polar regions represent the best sites for placing the instrument, due to the extremely low Precipitable Water Vapor and to the stable environmental conditions during the polar night. These peculiar conditions however represent a technological challenge and make necessary research and development in mechanics, cryogenics, electronics and automation.To achieve these goals, we address two solutions based on two instruments operating at Dome-C. The first one (BRAIN) consists of a bolometric interferometer that combines the high sensitivity of the bolometric detectors and the robustness of the interferometers and the second one (ClOVER), an imager. The two instruments, using orthogonal detection technologies, will provide a robust measurement of the B-modes. A pathfinder of the instrument has been funded by the Italian Antarctic Program in Italy and Programme National de Cosmologie and PNC in France and is under construction. It will be used to test in the field the technology to be used and to perform preliminary measurements of the polarized emission from the atmosphere and from the Galaxy. Masi S. et al., proceedings of the "Dome C Astronomy/Astrophysics Meeting ", CESR - Toulouse, june 28th to july 1st 2004; http://www.cesr.fr/~moly/domec/divers/presentations/Masi.pdf

What significant advance(s) in relation to the IPY themes and targets can be anticipated from this project?
Theme 4 - The main topic of the project is the investigation of new frontiers in the human knowledge. We expect that the instrument will be able to detect the cosmological background of gravitational waves and to explore the inflationary era.It will be also a major tool to study the matter distribution in the Universe as well as the nature of the Dark Energy.To control all the systematic effects will be necessary to improve knowledgeof polarization sources in the atmosphere and in our Galaxy.Theme 5 – The installation of an automated laboratory able to work during the winter in Dome C can be a significant advance for the scientific results from that base. Target, legacy - The instrument will be available in Dome C as a legacy for future experiments.

What international collaboration is involved in this project?
The project involves scientists and engineers from Italy, France,UK and USA.

FIELD ACTIVITY DETAILS

Geographical location(s) for the proposed field activities:
We propose to mount the telescopes at the Concordia Station at Dome C, Antarctica.Svalbard Islands will be the location for first testing the equipment during winter. Due to the latitude location, symmetrical with respect to dome-C, we can easily check there our scan strategy for systematic effects and the performance of the system at low temperatures.

Approximate timeframe(s) for proposed field activities:
Arctic: Feb/2005 – July/2005            
Antarctic: 2005/2006      2006/2007      2007/2008

Significant facilities will be required for this project:
The project needs a large amount of material delivered in Dome C for the assembly of the instrument. The project will provide its own facility to house the electronic interface for the instruments, a working lab, heat, power generation, and instrumentation. Main requirements are power (generator, about 10 kW), personnel and transportation of personnel and equipment to Dome C.

Will the project leave a legacy of infrastructure?
The millimetric observatory with fully automated cryogenic system will be available in Dome C . A weatherport has been modified and an intelligent system controls the temperatures of the various experiment parts. It can be operated remotely, and housekeeping data are transmitted via satellite, reducing the risks for the winterover personnel.

How is it envisaged that the required logistic support will be secured?
Consortium
Own national polar operator
National agency

The initial BRAIN/ClOVER experiment has been developed through independent logistics support of an experienced polar research program manager with over 18 years of supporting international research stations and remote field camps in the Arctic and Antarctica.

Has the project been "endorsed" at a national or international level?
Yes, The pathfinder experiment has been funded by MURST and PNRA in Italy and by PPARC in UK, and Programme National de Cosmologie and PNC in France. The Expression of interest is in the process of being considered by the Italian National Committee for IPY

PROJECT MANAGEMENT AND STRUCTURE

Is the project a short-term expansion (over the IPY 2007-2008 timeframe) of an existing plan, programme or initiative or is it a new autonomous proposal?
Yes
The program has been presented at PPARC (UK), MIUR and PNRA (Italy) and IPEV and IN2P3 (France).

How will the project be organised and managed?
The program will be managed by a Project Manager Board composed by Italian, French and British scientists.

What are the initial plans of the project for addressing the education, outreach and communication issues outlined in the Framework document?
A number of students are involved in the design, realization and integration of the instrument. Devoted electronics, mechanics, optics and cryogenics are under development. In parallel scientists and students are developing the tools dedicated to data analysis and studying the possible theoretical interpretation of the results.

What are the initial plans of the project to address data management issues (as outlined in the Framework document)?
The data products will be available for scientists worldwide, through scientific collaboration on specific topics.

How is it proposed to fund the project?
The Path Finder to BRAIN/ClOVER has been partially funded by MIUR and PNRA in Italy, PPARC in UK, IPEV and IN2P3 in France.

Is there additional information you wish to provide?
Polarization measurements are for CMB as important as EPICA has been for glaceology, and many different experiments are just startingto dig into it, both from ground and from the Space. One of the issues for ground based experiments is the geographycal position allowing the experiment to scan the regions of the sky clean from foreground contaminations, and allowing a scan strategy minimizing the possible systematic effects, and spurious effects due to the presence of the earth atmosphere. Dome-C has been shown to be one of the best sites for these kind of observations and we are trying to take advantage of this facility for astrophysics.The use of cryocoolers and of the last generation of bolometric detector arrays (TES) and their low noise SQUID readout may find applications also in other fields, such as non destructive polarization properties tests of ice carrots, to be performed in place.The cryogenics and the automated lab are facilities that will be available to the whole astrophysics community, in a cooperative spirit, as it should be for the whole research in Antarctica.

PROPOSER DETAILS

Dr. Silvia Masi
University of Roma “La Sapienza”
Dipartimento di Fisica
P.le A. Moro, 5. ROMA
00185
Italy

Tel: +39 06 49914690
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Fax: +39 06 4957697
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Other Information