Emittance Dilution in 1 and 5 TeV 30 GHz Linear Colliders

In this paper, we describe the single and multi-bunch sources of emittance dilution in the linacs of both 1 and 5 TeV center-of-mass energy linear colliders. The linacs operate at high rf accelerating gradients with a frequency around 30 GHz. At this high accelerating frequency, the wakefields are very strong and we discuss the BNS damping and correction procedures as well as the alignment and construction tolerances that are required to preserve the transverse emittance. Finally, because the collider must operate with long bunch trains, we consider the multi-bunch emittance dilution for a few cases where either the long-range transverse wakefield is damped or it is decreased by a combination of weak damping and detuning

Simulation Package based on Placet

The program PLACET is used to simulate transverse and longitudinal beam effects in the main linac, the drive-beam accelerator and the drive-beam decelerators of CLIC, as well as in the linac of CTF3. It provides different models of accelerating and decelerating structures, linear optics and thin multipoles. Several methods of beam-based alignment, including emittance tuning bumps and feedback, and different failure modes can be simulated. An interface to the beam-beam simulation code GUINEA-PIG exists. Currently, interfaces to MAD and TRANSPORT are under development and an extension to transfer lines and bunch compressors is also being made. In the future, the simulations will need to be performed by many users, which requires a simplified user interface. The paper describes the status of PLACET and plans for the futu

Final-Focus System for CLIC at 3 TeV

We describe a base-line optics for a 3-TeV final-focus system of the Compact Linear Collider (CLIC). The proposed system consists of an initial beta-matching region, two chromatic correction sections, and a final transformer, and it provides a total demagnification by a factor 90 horizontally and 346 vertically. The length per side amounts to 3.3 km. The effect of synchrotron radiation and higher-order aberrations is minimised by an odd dispersion function in the chromatic correction section. For a total flat energy spread of 1%, the system promises a luminosity of about 80% of the ideal. The 20-30% spot-size dilutions in the two transverse planes reflect a trade-off between the Oide effect and higher-order chromo-geometric aberrations

Status of the CLIC study on magnet stabilisation and time-dependent luminosity

The nanometer beam size at the CLIC interaction point imposes magnet vibration tolerances that range from 0.2 nm to a few nanometers. This is well below the floor vibra-tion usually observed. A test stand for magnet stability was set-up at CERN in the immediate neighborhood of roads, operating accelerators, manual shops, and regular office space. It was equipped with modern stabilization tech-nology. First results are presented, demonstrating signif-icant damping of floor vibration. CLIC quadrupoles have been stabilized vertically to an rms motion of (0.9 ± 0.1) n above 4 Hz, or (1.3 ± 0.2) nm with a nominal flow of cooling water. For the horizontal and longitudinal directions respectively, a CLIC quadrupole was stabilized to (0.4 ± 0.1) nm and (3.2 ± 0.4) nm

Work Plans of the EUROTeV Technical Work Packages for 2005-2007

This report summarises the status of the work in the seven scientific Work Packages of EUROTeV as presented during the ILC-European Regional Meeting at Royal Holloway in June 2005. The purpose of the meeting was to monitor the progress and to contrast the developments inside EUROTeV with the worldwide developments of the GDE. The presentations of the entire meeting are available from http://www.pp.rhul.ac.uk/workshop/

A 1.5g SMA-actuated Microglider looking for the Light

Unpowered flight can be used in microrobotics to overcome ground obstacles and to increase the traveling distance per energy unit. In order to explore the potential of goal-directed gliding in the domain of miniature robotics, we developed a 22cm microglider weighing a mere 1.5g and flying at around 1.5m/s. It is equipped with sensors and electronics to achieve phototaxis, which can be seen as a minimal level of control autonomy. A novel 0.2g Shape Memory Alloy (SMA) actuator for steering control has been specifically designed and integrated to keep the overall weight as low as possible. In order to characterize autonomous operation of this robot, we developed an experimental setup consisting of a launching device and a light source positioned 1m below and 4m away with varying angles with respect to the launching direction. Statistical analysis of 36 autonomous flights demonstrate its flight and phototaxis efficiency

A 1.5g SMA-actuated Microglider looking for the Light

Unpowered flight can be used in microrobotics to overcome ground obstacles and to increase the traveling distance per energy unit. In order to explore the potential of goal-directed gliding in the domain of miniature robotics, we developed a 22cm microglider weighing a mere 1.5g and flying at around 1.5m/s. It is equipped with sensors and electronics to achieve phototaxis, which can be seen as a minimal level of control autonomy. A novel 0.2g Shape Memory Alloy (SMA) actuator for steering control has been specifically designed and integrated to keep the overall weight as low as possible. In order to characterize autonomous operation of this robot, we developed an experimental setup consisting of a launching device and a light source positioned 1m below and 4m away with varying angles with respect to the launching direction. Statistical analysis of 36 autonomous flights demonstrate its flight and phototaxis efficiency

The CLIC Study of Magnet Stability and Time-dependent Luminosity Performance

The present parameters of the CLIC study require the collision of small emittance beams with a vertical spot size of 1 nm. The tolerances on vertical quadrupole vi-bration (above a few Hz) are as small as a few nm in the linac and most of the Final Focus. The final focusing quadrupole has a stability requirement of 4 nm in the horizontal and 0.2 nm in the vertical direction. Those tol-erances can only be achieved with the use of damped support structures for CLIC. A study has been set-up at CERN to explore the application of stabilization devices from specialized industry and to predict the time-dependent luminosity performance for CLIC. The results will guide the specification of required technological im-provements and will help to verify the feasibility of the present CLIC parameters

Epitope mapping and fine specificity of human T and B cell responses for novel candidate blood-stage malaria vaccine P27A

P27A is a novel synthetic malaria vaccine candidate derived from the blood stage Plasmodium falciparum protein Trophozoite Exported Protein 1 (TEX1/PFF0165c). In phase 1a/1b clinical trials in malaria unexposed adults in Switzerland and in malaria pre-exposed adults in Tanzania, P27A formulated with Alhydrogel and GLA-SE adjuvants induced antigen-specific antibodies and T-cell activity. The GLA-SE adjuvant induced significantly stronger humoral responses than the Alhydrogel adjuvant. Groups of pre-exposed and unexposed subjects received identical vaccine formulations, which supported the comparison of the cellular and humoral response to P27A in terms of fine specificity and affinity for populations and adjuvants. Globally, fine specificity of the T and B cell responses exhibited preferred recognized sequences and did not highlight major differences between adjuvants or populations. Affinity of anti-P27A antibodies was around 10−8 M in all groups. Pre-exposed volunteers presented anti-P27A with higher affinity than unexposed volunteers. Increasing the dose of GLA-SE from 2.5 to 5 μg in pre-exposed volunteers improved anti-P27A affinity and decreased the number of recognized epitopes. These results indicate a higher maturation of the humoral response in pre-exposed volunteers, particularly when immunized with P27A formulated with 5 μg GLA-SE