The front-end electronics for the calorimeter triggers

2000-010 Abstract This note describes the technical implementation of the first part of the Level0 Calorimeter trigger, the one integrated in the front-end card After a short review of the overall system, the architecture of the front-end card is depicted. Then the main operation, sum and select, is described in detail, with the FPGA implementation. The connection problem is then address, with cable and backplane solutions. Simulation, and future work is also described

MAROC: Multi-Anode readout chip

MAROC is the readout chip designed for the ATLAS luminometer made of Roman pots. This ASIC has been realised in SiGe 0.35µm technology and is an evolution of the OPERA_ROC ASIC developed and installed on the OPERA experiment to auto-trigger and readout 64 channels Hamamatsu multi anode PMTs. Its main features are a 100% trigger rate for signal greater than 1/3 photoelectron, a charge measurement up to 30 photoelectrons with a linearity of 2% or better and a crosstalk less than 1%. A 12-bit Wilkinson ADC has been embedded to digitalise charge measurement. In order to check the functionalities of MAROC, laboratory tests have been performed and have showed a good global behaviour of the chip, which allows using it for beam tests of a complete Roman Pot at CERN during autumn 2007

The front end electronics for LHCb calorimeters

The electronics for the electromagnetic and hadronic calorimeters of LHCb is under design. The 32 channel-9U front-end board offers the complete front-end and readout electronics for every channel including original shaping, 12bit-40MHz ADC, digital filtering and latency for level 0 and level 1 triggers. The clipped PM input signal is integrated during 25ns, but also delayed then subtracted to itself 25ns later which allows performant pile up independence. This board also includes the first processing levels of the L0 calorimeter trigger. A 16 channel-6U prototype board has been designed and used at CERN in test beam in 1999

Isotopic fission fragment distributions as a deep probe to fusion-fission dynamics

During the fission process, the atomic nucleus deforms and elongates up to the two fragments inception and their final separation at the scission deformation. The evolution of the nucleus energy with deformation defines a potential energy landscape in the multidimensional deformation space. It is determined by the macroscopic properties of the nucleus, and is also strongly influenced by the single-particle structure of the nucleus, which modifies the macroscopic energy minima. The fission fragment distribution is a direct consequence of the deformation path the nucleus has encountered, and therefore is the most genuine experimental observation of the potential energy landscape of the deforming nucleus. Very asymmetric fusion-fission reactions at energy close to the Coulomb barrier, produce well-defined conditions of the compound nucleus formation, where processes such as quasi-fission, pre-equilibrium emission and incomplete fusion are negligible. In the same time, the excitation energy is sufficient to reduce significantly structural effects, and mostly the macroscopic part of the potential is responsible for the formation of the fission fragments. We use inverse kinematics combined with a spectrometer to select and identify the fission fragments produced in 238U+12C at a bombarding energy close to and well-above the Coulomb barrier. For the first time, the isotopic yields are measured over the complete atomic-number distribution, between Z=30 and Z=63. In the experimental set-up, it is also possible to identify transfer-induced reactions, which lead to low-energy fissio