Commissioning of the ALTO 50 MeV electron linac

online : http://accelconf.web.cern.ch/AccelConf/e06/PAPERS/MOPLS113.pdfThe ALTO 50 MeV electron linac is dedicated to the production of neutron-rich radioactive nuclei using the photo-fission process and the optimisation of the targetion source system for SPIRAL 2 and EURISOL projects. The accelerator consists of a 3 MeV injector (old test station of LAL, Laboratoire de l'Accélérateur Linéaire d'Orsay), LIL (Linac Injector of LEP) accelerating structure, RF power plant, beam line, control system and diagnostics. Specified and measured beam parameters will be compared to show the performances of the photofission process and eventually other applications

TTF-FEL photoinjector simulation giving a high quality beam

In this paper we present a study of the beam quality at the TESLA FEL photoinjector exit. The beam dynamics is simulated by ATRAP which is a 2D1/2 numerical code using the Lienard-Wiechert potential to calculate the space charge force. For this study the injector geometry and the magnetic field are given by Klaus Floettmann. We don't take into account the thermal emittance in the beam dynamics, because we don't know the energy and velocity profile at the cathode exit. But, with some assumptions, we find that it can be the major part of the transverse emittance

High-intensity proton SC linac using spoke cavities

This paper describes the studies going on at IPN-Orsay concerning the conception and the design of a superconducting proton linac using spoke cavities. Different linac concepts from 5 MeV up to 80-100 MeV have been investigated, mainly based on beam dynamics studies, and especially caring about reliability and safety aspects. The study leads to a final proposal of a high-intensity proton linac using spoke cavities, that could be proposed in the frame of the XADS project

INSTRUMENTS IL METHODS IN PHYSICS RESEARCH TESLA FEL photo-injector simulations giving high-quality beams

Abstract To obtain a high-brightness beam for the TESLA FEL project, operating in the VUV region, a photo-injector providing a high-quality beam is needed, i.e., the rms radial and longitudinal emittances must be, respectively, of the order of 1 mm mrad and 20 mm KeV [ 11. With these drastic conditions, we cannot use an analytical model with some approximations or scale laws, a refined study of the beam dynamics with a numerical code is necessary. The quality optimization is all the more difficult since many parameters play a role in the beam dynamics. The beam dynamics is simulated by the numerical code ATRAP (Acceleration and TRAnsport of Particles) [2-51, using the Lienard-Wiechert's equations to describe the self-electromagnetic field. To reduce the total time of this optimization, we have chosen the RF peak field on the cathode, between 40 and 60 MV/m, high enough to decrease the space charge effect and not too high to avoid the defocusing effect of the RF field. In this paper, we show the influence of the different parameters on the beam quality

Pulse shape discrimination for GRIT: Beam test of a new integrated charge and current preamplifier coupled with high granularity Silicon detectors

International audienceThe GRIT (Granularity, Resolution, Identification, Transparency) Silicon array is intended to measure direct reactions. Its design is based on several layers (three layers in the forward direction, two backward) of custom-made trapezoidal and square detectors. The first stage is 500 μm thick and features 128 × 128 orthogonal strips. Pulse shape analysis for particle identification is implemented for this first layer. Given the compacity of this array and the large number of channels involved (>7500), an integrated preamplifier, iPACI, that gives charge and current information has been developed in the AMS 0.35 μm BiCMOS technology. The design specifications and results of the test bench are presented. Considering an energy range of 50 MeV and an energy resolution (FWHM) of 12 keV (FWHM) for the preamplifier, the energy resolution for one strip obtained from alpha source measurement in real conditions is 35 keV. The current output bandwidth is measured at 130 MHz for small signals and the power consumption reaches 40 mW per detector channel. A first beam test was performed coupling a nTD trapezoidal double-sided stripped Silicon detector of GRIT with the iPACI preamplifier and a 64-channel digitizer. Z = 1 particles are discriminated with pulse shape analysis technique down to 2 MeV for protons, 2.5 MeV for deuterons and 3 MeV for tritons. The effect of the strip length due to the trapezoidal shape of the detector is investigated on both the N- and the P-side, showing no significant impact

The ALTO project: a 50 MeV electron beam at IPN Orsay

ACC SPR NI

The study of a new PARRNe experimental area using an electron linac close to the Orsay tandem

The Production of neutron-rich radioactive nuclei through fission is currently prime of research interest for the future radioactive beam facilities. For example in the EURISOL[1] project, photo-fission and fast neutron induced fission are proposed. The photo-fission cross-section for 238U is about 0.16 barn (against 1.6 barn for fast neutrons of 40 MeV) but the conversion electrons/gammas is much more efficient than that of deuterons/neutrons. It was necessary, to test this new method of production, to carry out, in equivalent conditions, an experiment of the type PARRNe-1 using a 50 MeV electron beam. In April 2001, production of fission fragments induced by gammas proved to be successful. Bremsstrahlung gamma rays were produced by the few nA-50 MeV electron beam delivered by the CERN LEP Injector Linac (LIL). This promising alternative has stimulated the study of a new experimental area at IPNO based on an electron Linac close to the Tandem, through a collaboration with LAL and CERN PS groups

Photo-fission for the production of radioactive beams ALTO project

In order to probe neutron rich radioactive noble gases produced by photo-fission, a PARRNe-1 experiment (Production d'Atomes Radioactifs Riches en Neutrons) has been carried out at CERN. The incident electron beam of 50 MeV was delivered by the LIL machine: LEP Injector Linac. The experiment allowed us to compare under the same conditions two production methods of radioactive noble gases: fission induced by fast neutrons and photo-fission. The obtained results show that the use of the electrons is a promising mode to get intense neutron rich ion beams. After the success of this photo-fission experiment, a conceptual design for the installation at IPN Orsay of a 50 MeV electron accelerator close to the PARRNe-2 device has been worked out: ALTO Project. This work has started within a collaboration between IPNO, LAL (Laboratoire de l'Accelerateur Lineaire) and CERN groups