Study on the response of IFMIF fission chambers to mixed neutron-gamma fields: PH-2 experimental tests

The engineering design of fissionchambers as on-line radiation detectors for IFMIF is being performed in the framework of the IFMIF-EVEDA works. In this paper the results of the experiments performed in the BR2 reactor during the phase-2 of the foreseen validation activities are addressed. Two detectors have been tested in a mixedneutron-gamma field with high neutron fluence and gamma absorbed dose rates, comparable with the expected values in the HFTM in IFMIF. Since the neutron spectra in all BR2 channels are dominated by the thermal neutron component, the detectors have been surrounded by a cylindrical gadolinium screen to cut the thermal neutron component, in order to get a more representative test for IFMIF conditions. The integrated gamma absorbed dose was about 4 × 1010 Gy and the fast neutron fluence (E > 0.1 MeV) 4 × 1020 n/cm2. The fissionchambers were calibrated in three BR2 channels with different neutron-to-gamma ratio, and the long-term evolution of the signals was studied and compared with theoretical calculations

The role of spatial and temporal radiation deposition in inertial fusion chambers: the case of HiPER¿

The first wall armour for the reactor chamber of HiPER will have to face short energy pulses of 5 to 20 MJ mostly in the form of x-rays and charged particles at a repetition rate of 5–10 Hz. Armour material and chamber dimensions have to be chosen to avoid/minimize damage to the chamber, ensuring the proper functioning of the facility during its planned lifetime. The maximum energy fluence that the armour can withstand without risk of failure, is determined by temporal and spatial deposition of the radiation energy inside the material. In this paper, simulations on the thermal effect of the radiation–armour interaction are carried out with an increasing definition of the temporal and spatial deposition of energy to prove their influence on the final results. These calculations will lead us to present the first values of the thermo-mechanical behaviour of the tungsten armour designed for the HiPER project under a shock ignition target of 48 MJ. The results will show that only the crossing of the plasticity limit in the first few micrometres might be a threat after thousands of shots for the survivability of the armour.

Temperature Evolution and Light Species Diffusion in Armor and Structural Material for Inertial Fusion Reactor Chambers: a Case for HiPER 4a

One of the most advance designs for HiPER fusion reactor is a spherical chamber 10 m in diameter based on dry wall concept. In this system, the first wall will have to withstand short energy pulses of 5 to 20 MJ at a repetition rate of 0.5-10 Hz mostly in form of X-rays and charged particles. To avoid melting of the inner surface, the first wall consists on a thin armor attached to the structural material. Thickness (th) and material of each layer have to be chosen to assure the proper functioning of the facility during its planned lifetime.

Draft of law related to the settling of chambers after Commencement, 1742

One-page handwritten draft of a law created by the president and tutors requiring juniors to inform the Faculty of their intent to stay in dormitory rooms following Commencement. The document is undated and unsigned, but appears to be in the hand of President Edward Holyoke, and has a note in shorthand in the left margin. The text is included in College Book IV and was presented at a meeting of the Harvard Corporation on September 6, 1742.

Settlement of chambers, 1741-1764

The book is comprised of folio-sized pages conserved in a modern soft-cover binding. The volume consists of yearly handwritten lists of dormitory room assignments for the years 1741-1753 and 1761-1764. Students are listed by last name and building names are often abbreviated as "M" for Massachusetts Hall, "S" for Stoughton Hall, and "O" for Old College or Harvard Hall. The organizational pattern varies by list, some are alphabetical, others arranged by building and room number. The lists for 1743, 1748, 1749, 1761-1764 also note students living outside of the College and their locations. The lists for 1761-1764 also include the waiters and monitors for the academic year.

Ionization chambers and counters : experimental techniques /

Mode of access: Internet.

Chambers's miscellany of useful and entertaining tracts.

Added t.p.: Edinburgh : William and Robert Chambers.

Chambers' papers for the people.

Mode of access: Internet.

Chambers's miscellany of useful and entertaining tracts.

Edited by William and Robert Chambers.

Chambers's pocket miscellany.

Mode of access: Internet.