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The ISIS neutron and muon source, located in the UK, consists of an H⁻ linear accelerator, a rapid cycling proton synchrotron and extraction lines to two target stations. A project is currently under way to replace the target assembly of the First Target Station (TS1) in order to secure its continued operation and improve operational flexibility. In addition to a number of other diagnostic tools, a new secondary emission (SEM) grid profile monitor is expected to be located within the helium atmosphere of the new target assembly. To investigate the performance of an out-of-vacuum SEM grid, a prototype monitor was positioned in-air between a beam exit window and a dump. Profile measurements taken with this monitor are presented, including tests at a range of bias voltages with a fast data acquisition system to investigate secondary signal sources., Proceedings of the 8th International Beam Instrumentation Conference, IBIC2019, Malmö, Sweden

Beam loss monitoring at the ISIS Neutron and Muon Source is primarily carried out with the use of gas ionisation chambers filled with argon. These chambers are 3 to 4m long and are positioned around the inside of the synchrotron as well as along the ISIS Linac and Extracted Proton Beamlines (EPBs). To achieve finer spatial resolution a programme has been implemented to install six scintillator Beam Loss Monitors (BLMs), each 300 mm long, inside each of the ten main dipole magnets. Using these scintillator BLMs the accelerator can be fine-tuned during set-up to reduce areas of beam loss that were previously unseen or hard to characterise. As the installation programme comes to an end, this paper will review: the installation of the scintillator BLMs, the electronic hardware and software used to control them, and the initial measurements that have been taken using them., Proceedings of the 7\textsuperscript{th} Int. Beam Instrumentation Conf., IBIC2018, Shanghai, China

The ISIS Neutron and Muon Source, located in the UK, consists of a H⁻ linear accelerator, a rapid cycling proton synchrotron and two extraction lines delivering protons onto heavy metal targets. One of the limiting factors for achieving higher intensities in the accelerator is the head-tail instability present in the synchrotron, around 2ms after injection. In order to mitigate this instability, an experimental damping system is being developed for the ISIS synchrotron. Initial tests using a split electrode BPM as a pickup and a ferrite loaded kicker as a damper showed positive results. This paper describes the different developments made to the damping system and planned improvements to optimize its performance for use in normal operations., Proceedings of the 8th International Beam Instrumentation Conference, IBIC2019, Malmö, Sweden

The ISIS-II project aims to deliver a new spallation neu- tron source by 2034, driven by a 1.2 GeV proton accelerator capable of delivering a beam power of 1.25 MW with a rep- etition rate of 50 Hz or higher. One of the options for this future accelerator is a Fixed Field alternating gradient Accelerator (FFA). To demonstrate the suitability of FFAs for use in a user facility such as ISIS, there is a plan to construct a smaller scale proof of concept machine: FETS-FFA. Developing beam diagnostics for the FETS-FFA ring presents a challenge due to a large orbit excursion and aperture ( 60 mm x 700 mm). Diagnostics must cover the full size of beam chamber whilst still providing measurement sensitivity and resolution comparable to that seen in the ISIS synchrotron. This paper presents the current design and development of beam diagnostics for the FETS-FFA ring, including finite element studies of Beam Position Monitors (BPMs) and Ionisation Profile Monitors (IPMs)., Proceedings of the 8th International Beam Instrumentation Conference, IBIC2019, Malmö, Sweden

The ISIS Facility at the Rutherford Appleton Laboratory produces intense neutron and muon beams for condensed matter research. Since 1984 its 50 Hz, rapid cycling synchrotron has accelerated protons from 70 to 800 MeV and now typically delivers 0.2 MW of beam to two target stations supplying thirty-four instruments. Control and minimisation of beam loss is vital to the success of high-power proton accelerators. Coverage and sensitivity of beam loss monitoring at ISIS has recently been improved by the installation of scintillating monitors inside the synchrotron’s main dipoles. In addition to their primary goal of preventing damage to dipole RF screens, these monitors have also provided a highly sensitive tool for empirical accelerator optimisation., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

The ISIS Neutron and Muon Source, located in the UK, consists of a H⁻ linear accelerator, a rapid cycling proton synchrotron and extraction lines connecting two target stations. Transverse beam instabilities are one the major factors limiting the intensity of the proton beam. In order to mitigate these instabilities, an experimental damping system is being developed for the ISIS synchrotron. This system uses a split electrode BPM as a pickup and a ferrite loaded kicker as a damper. This kicker is ordinarily used to excite the beam with a fast rise time pulse for tune measurements. This paper describes the utilization of this device within a fast feedback system, using the continuous waveform provided by a split electrode BPM which is processed by an FPGA board., Proceedings of the 6th Int. Beam Instrumentation Conf., IBIC2017, Grand Rapids, MI, USA

Non-destructive beam profile measurements at the ISIS neutron source are performed using Multi-Channel Profile Monitors (MCPMs). These use residual gas ionisation within the beam pipe, with the ions being guided to an array of 40 Channeltron electron multipliers by a high voltage drift field. Non-uniform transverse electric fields within these monitors are caused by the drift field and the beam's space charge. Longitudinally, a saddle point located between the drift field plate and the opposing compensating field plate introduces extra complexity into the ion motion. To allow for detailed studies of this behaviour, an MCPM has been placed in Extracted Proton Beamline 1 (EPB1) where the beam is well defined. Simulations of the profiles obtained by this monitor are performed using machine measurements, CST EM Studio and a simple C++ particle tracking code. This paper describes the process used to simulate MCPM profiles along with a comparison of simulated and measured results. Trajectories of detected ions from their creation to the Channeltrons are discussed, together with a study of Channeltron detection characteristics carried out in the ISIS diagnostics laboratory vacuum tank., Proceedings of the 5th Int. Beam Instrumentation Conf., IBIC2016, Barcelona, Spain

During routine operation, the radiation levels in the ISIS proton synchrotron become high enough to permanently affect systems and electronics. This can potentially cause critical components to fail unexpectedly or denature over time, causing disruption for users of the ISIS facility or a loss of accuracy on a number of systems. To study the long term effects of ionising radiation on ISIS systems and electronics, the total dose received by such components must be recorded. A semiconductor based online Total Ionisation Dosimeter (TID) was developed to do this, using pin diodes and Radiation sensing Field Effect Transistors (RadFETs) to measure the total ionisation dose. Measurements are made by feeding the TIDs with a constant current, with the threshold voltage on each device increasing in relation to the amount of radiation that it has received. This paper will look at preliminary offline results using off the shelf Field Effect Transistors (FETs) and diodes, before discussing the development of the RadFET online monitor and the results it has gathered thus far. Finally the paper will look at future applications and studies that this type of monitor will enable., Proceedings of the 5th Int. Beam Instrumentation Conf., IBIC2016, Barcelona, Spain

Wire scanners and secondary emission (SEM) grids are used for measurements of transverse beam profile at the ISIS neutron and muon source. Silicon carbide-coated carbon fibre wires are used in profile monitors throughout the ISIS accelerator. One such SEM grid is currently installed close to the target in EPB2 and is intercepted by the 800 MeV proton beam at a repetition rate of 10 Hz. Future profile measurements will require another of these monitors to be installed close to the target in EPB1; intercepted with a repetition rate of 40 Hz. Wires intercepting the ion beam are heated due to the deposition of beam-energy. Thermal simulations for the higher repetition rate were performed using ANSYS and a numerical code. The numerical code was then expanded to include various beam, wire and material properties. Assumptions for temperature dependent material emissivities and heat capacities were included in the simulation. Estimated temperatures due to the energy deposited by protons, and approximate values of deposited energy from the expected neutron flux are presented. The effects on wire-temperature of various beam and wire parameters are also discussed., Proceedings of the 5th Int. Beam Instrumentation Conf., IBIC2016, Barcelona, Spain

The ISIS spallation neutron and muon source has been in operation since 1984. The accelerator complex consists of an H⁻ ion source, 665 keV RFQ, 70 MeV linac, 800 MeV proton synchrotron and associated beam transfer lines. The facility currently delivers ~2.8·10¹³ protons per pulse (ppp) at 50 Hz, which is shared between two target stations. High intensity performance and operation are dominated by the need to minimise and control beam loss, which is key to sustainable machine operation, allowing essential hands on maintenance. The facility has had several upgrades including an RFQ, ring Second Harmonic RF system, key developments of diagnostics and instrumentation required for improving beam control and a Second Target station. Upgrades being installed, or expected in the near future, include: a ring damping system, a new injector MEBT with fast injection chopper and an upgraded 50 Hz target. Operational experience of ISIS and the impacts of its past and future upgrades are discussed. Ideas for major upgrades to ISIS are briefly reviewed, as are the underlying R&D projects., Proceedings of the 57th ICFA Advanced Beam Dynamics Workshop on High-Intensity and High-Brightness Hadron Beams, HB2016, Malmö, Sweden