Bremsstrahlung gamma radiation and neutrons are produced during the operation of high-energy linear accelerators. A single circular tunnel is built for the X-ray Free Electron Laser (X-FEL), therefore most of electronic devices used to control the machine are going to be placed in the same vault as the main beam pipe. Therefore, the devices will be subjected to neutron and gamma radiation influence. Knowledge of neutron and gamma doses are crucial to understand and interpret radiation effects on electronic devices and systems dedicated to the operation in the environment of high-energy linear accelerators. Indeed, it is advisable to monitor radiation produced in the tunnel of X-FEL in real time to estimate the danger and the life-time of electronic components and devices. The realtime monitoring system dedicated to measure radiation produced in a linear accelerator tunnel was designed. The system utilizes two different types of detectors to gauge neutron fluence and gamma radiation dose during the operation of the accelerator driving X-FEL. Research described in this paper is focused on real time gamma radiation dosimetry. Silicon-based gamma-sensitive dosimeter RadFET was employed to quantify radiation produced during an operation of a linear accelerator. In order to fully investigate the feasibility of RadFET detector for gamma dosimetry various experiments and gamma radiation exposure tests were carried out using a cesium source and inside FLASH (Free Electron Laser At Hamburg) facility placed in a high-energy Research Centre DESY.
LLRF control system consists of a few basic subsystems with the basic aim to give good quality beam from the XFEL laser. Some of the se subsystems, which are described here are: transient detector, finite state machine, precise timing distribution network, EM field stabilization control loop, etc. The paper summarizes the latest developments of these systems done during the last year.
We have investigated the radiation environment of the electron linear accelerators operating at DESY and explicitly identified the neutron and gamma radiation fields. Furthermore, we have studied the effects of the above radiations as well as neutrons from a dedicated irradiation device on various electronic components including CCD cameras and SRAM microchips. This report will highlight the activities currently undertaken by the radiation effect project group under the Accelerator Radiation Control (MSK) section of DESY.
<sup></sup>Electronic components during High Energy Physics experiments are exposed to high level of radiation. Radiation
environment causes many problems to electronic devices. The goal of several experiments done at DESY (Deutsches Elektronen Synchrotron, Hamburg) was to investigate nature of irradiation effects, caused damages and possible techniques of mitigation. One of aspects of experiments is radiation measurements. The propositions of building radiation monitoring system, using different semiconductor components, are presented. Second aspect is radiation tolerance. Different electronic devices were tested: FPGA chips, CCD sensors, bubble dosimeters and LED diodes. Components were irradiated in TESLA Test Facility 2 tunnel and in laboratory using <sup>241</sup><i>Am/Be</i> neutron source. The results of experiments are included and discussed.
Strong fields of bremsstrahlung photons and photoneutrons are produced during the operation of high-energy electron linacs. Therefore, a mixed gamma and neutron radiation field dominates the accelerators environment. The gamma radiation induced Total Ionizing Dose (TID) effect manifests the long-term deterioration of the electronic devices operating in accelerator environment. On the other hand, the neutron radiation is responsible for Single Event Effects (SEE) and may cause a temporal loss of functionality of electronic systems. This phenomenon is known as Single Event Upset (SEU). The neutron dose (KERMA) was used to scale the neutron induced SEU in the SRAM chips. Hence, in order to estimate the neutron KERMA conversion factor for Silicon (Si), dedicated calibration experiments using an Americium-Beryllium (<sup>241</sup>Am/Be) neutron standard source was carried out. Single Event Upset (SEU) influences the short-term operation of SRAM compared to the gamma induced TID effect. We are at present investigating the feasibility of an SRAM based real-time beam-loss monitor for high-energy accelerators utilizing the SEU caused by fast neutrons. This paper highlights the effects of gamma and neutron radiations on Static Random Access Memory (SRAM), placed at selected locations near the Superconducting Linear Accelerator driving the Vacuum UV Free Electron Laser (VUVFEL) of DESY.
Electronic components during High Energy Physics experiments are exposed to high level of radiation. Radiation environment causes many problems to electronic devices. This report highlights the major hazards to electronics caused by radiation. Several experiments were done and results are included.