The CLAS12 Forward Tagger

This document presents the technical layout and the performance of the CLAS12 Forward Tagger (FT). The FT, composed of an electromagnetic calorimeter based on PbWO4 crystals (FT-Cal), a scintillation hodoscope (FT-Hodo), and several layers of Micromegas trackers (FT-Trk), has been designed to detect electrons and photons scattered at polar angles from 2∘ to 5∘ and to meet the physics goals of the hadron spectroscopy program and other experiments running with the CLAS12 spectrometer in Hall B

PROGRESS ON THE SRF LINAC DEVELOPMENTS FOR THE IFMIF- LIPAC PROJECT

Abstract In the framework of the International Fusion Materials Irradiation Facility (IFMIF), which consists of two high power accelerator drivers, each delivering a 125 mA deuteron beam at 40 MeV in CW, a Linear IFMIF Prototype Accelerator (LIPAc), is presently under design and realization for the first phase of the project [1]. This accelerator prototype includes a Superconducting RadioFrequency Linac (SRF Linac), which is designed for the transportation and focalization of the deuteron beam up to 9 MeV. This SRF Linac is a large cryomodule of ~6 m long, working at 4.4 K and at the frequency of 175 MHz in continuous wave. It is mainly composed of 8 low-beta Half-Wave Resonators (HWR), 8 Solenoid Packages and 8 RF Power Couplers. This paper focuses on the recent developments and changes made on the SRF Linac design: following the abandon of the HWR frequency tuning system, initially based on a plunger located inside the central region of the resonator, a new external tuning system has been designed, implying a complete redesign of the resonator and consequently impacting the cryomodule lattice. The recent changes in the design are presented in this paper. In addition, cold tests were performed on a HWR prototype and cold tests results of the magnets prototypes are also presented

The CLAS12 Micromegas Vertex Tracker

The Micromegas Vertex Tracker was designed to improve upon the tracking capabilities of the baseline design of the CLAS12 spectrometer in Hall B at Jefferson Laboratory. A Barrel Micromegas Tracker made with six concentric cylinders, each made of three 120-sector tiles, surrounds the Silicon Vertex Tracker, and a Forward Micromegas Tracker composed of 6 disks is placed 30 cm downstream of the liquid-hydrogen target. Both trackers sit in a 5 T solenoid magnetic field. All Micromegas elements are based on resistive technology to withstand luminosities up to 10^35 cm−2 s−1, as well as on bulk technology to enforce gain uniformity and mechanical robustness. Due to the high magnetic field, dedicated electronics have been designed and displaced 2 m away from the detectors. The electronics readout is based on the DREAM ASICs that allow sustained operation up to 20 kHz trigger rate at the maximum luminosity