Oleg Borisovich Malyshev

STFC Daresbury Laborarory Warrington · ASTeC

Accelerator laboratories worldwide are researching copper radio frequency (RF) cavities coated with superconducting thin films to exceed the limits of bulk niobium. The development and RF testing of thin films on small planar samples is vital before cavity depositions. A team at Daresbury Laboratory have developed a cost-effective facility using a...

The relatively high transition temperature of A15 superconducting materials makes them a potential alternative to Nb for radio-frequency applications. This paper presents the results of PVD deposition of one A15 material, V3Si, on Cu and sapphire substrates. The surface structure and composition of the films were characterised via SEM and EDX. The...

Transmission probability is an important parameter in vacuum science and technology that needs to be accurately characterised for system design. Typically, this is computed using the test particle Monte Carlo method. However, this approach is valid only in the free molecular regime. In this work, we propose a methodology to compute transmission pro...

Thin-film cavities with higher Tc superconductors (SC) than Nb promise to move the operating temperature from 2 to 4.5 K with savings 3 orders of magnitude in cryogenic power consumption. Several European labs are coordinating their efforts to obtain a first 1.3 GHz cavity prototype through the I.FAST collaboration and other informal collaborations...

Over recent years four dedicated facilities have been built at Daresbury Laboratory by a team working on thin film SRF cavities. Firstly, a conventional DC resistance facility allows measurements of critical temperature and residual resistance ratio. In addition, three other facilities were designed in house to address superconducting thin film (ST...

Bulk niobium is currently the material of choice for superconducting radio frequency (SRF) cavities and is a well matured process. However, it is possible that SRF cavities could be further improved beyond bulk Nb by sputtering thin Nb films onto Cu cavities. Copper has a greater thermal conductivity than Nb and is also easier to machine, whilst sp...

In this work, we have investigated two series of Nb/Cu samples deposited by HiPIMS technique, and differing in Nb deposition conditions, Nb film thickness and Cu substrate polishing techniques. All the films were additionally irradiated by Nd:YAG laser to smooth their surfaces. The impact of the magnetic field enhancement at the surface defects on...

The sustainable next generation particle accelerators require innovative solutions to overcome the current technological challenges set by existing bulk niobium supercon-ducting radio-frequency (SRF) cavities. Thin film-based multilayer structures in the form of superconductor-insula-tor-superconductor (SIS) may be the long-sought-after breakthroug...

Radio-frequency cavities used in particle accelerators are usually manufactured from two half cells that are electron beam welded together. In this case, the weld is located across the peak surface current of the cavity. This weld can lead to large increases in surface resistance and limit the performance of thin film coated cavities. Many problems...

Research is ongoing into the use of superconducting thin films to replace bulk niobium for future radio frequency (RF) cavities. A key part of this research requires measuring the RF properties of candidate films. However, coating and testing thin films on full-sized cavities is both costly and time-consuming. Instead, films are typically deposited...

Now that bulk Nb technology has reached it full maturity , improving SRF technology demands that new materials need to be developed. For reasons explained in the talk, all next generation SRF materials will be in the form of thin films. The IFAST project has the ambition to coordinate European activities on that topic, not only throughout its own p...

With the benefits of evenly distributed pumping, low thermal outgassing rate and low photon-/electron-/ion stimulated desorption yields, non-evaporable getter (NEG) coating has been widely used in particle accelerators for many years. Our earlier work has demonstrated the different thickness of Ti-Zr-V coating in the range of 0.1–1 μm affects its p...

The maximum accelerating gradient of superconducting radio frequency cavities are currently reaching their theoretical limits, due to the magnetic field entering the superconductor in the form of vortices. To overcome these limits, thin film coated superconducting materials are required, however these need to be tested to optimise their properties....

The maximum accelerating gradient of superconducting radio frequency (SRF) cavities are currently reaching their theoretical limits, due to the magnetic field entering the superconductor in the form of vortices. To overcome these limits, thin film coated superconducting materials are required, however these need to be tested to optimise their prope...

Non Evaporable Getter (NEG) coating has been employed extensively in the particle accelerator especially where the vacuum conductance of the vessel is severely restricted and ultra-high vacuum condition is required. NEG coating will significantly reduce the outgassing rate and provides active pumping surface for H2, CO and CO2. In addition, it has...

Titanium is one of the materials that used for production of accelerator vacuum chamber and components. In this paper we report the results of vacuum properties evaluation measurements of titanium vacuum chamber. The sample was produced from 40-mm inner diameter tube made of titanium and equipped with CF40 flanges at both ends. The electron stimula...

The research on superconducting thin films for future radio frequency (RF) cavities requires measuring the RF properties of these films. However, coating and testing thin films on full-sized cavities is both challenging and time-consuming. As a result, films are typically deposited on small, flat samples and characterised using a test cavity. At Da...

Non-evaporable getter (NEG) coatings can be activated at temperatures as low as 140°C. However, better pumping properties are achieved using higher temperatures, between 150-300 °C. This paper investigates whether using an increased activation duration can improve the NEG properties obtained using lower activation temperatures, and so decrease the...

Nb3Sn, NbTiN and NbN are superconductors with critical temperatures of 18.3, 12.6-17 and 11.6-17.5 K, respectively , these are higher than that of Nb at 9.3 K. Hence, at 4 K, they have an RF resistance, an order of magnitude lower than that of Nb, which leads to quality factors above those of Nb. In recent years, there has been an extensive effort...

Superconducting radiofrequency (SRF) cavities are vital components of particle accelerators nowadays. In order to minimise the energy dissipation, a perfect inner surface of the cavity, hindering the penetration of magnetic field, is required. In this work, we investigated 10 planar samples differing in the surface quality of Nb film deposited on C...

An international collaboration of research teams from CEA (France), CERN (Switzerland), INFN/LNL (Italy), HZB and USI (Germany), IEE (Slovakia), RTU (Latvia) and STFC/DL (UK), are working together on better understanding of how to improve the properties of superconduct-ing thin films (ScTF) for RF cavities. The collaboration has been formed as WP15...

Non-evaporable getter (NEG) coating is widely used for vacuum system of charged particle accelerators. The RF surface resistance of NEG coating is increasing with its thickness. Therefore, knowing how NEG coating properties depend on its thickness is essential for vacuum system design of accelerators. This paper describes the results of studying th...

In high intensity positively charged beam machined the beam intensity could be limited by the ion induced pressure instability. This is a phenomenon occurs when residual gas molecules can be ionised and accelerated towards beam chamber walls causing ion stimulated gas desorption and residual gas density increase. Under certain conditions residual g...

For the future high energy colliders being under the design at this moment, the choice of a low surface impedance beam screen coating material has become of fundamental importance to ensure sufficiently low beam impedance and consequently guaranteed stable operation at high currents. We have studied the use of high-temperature superconducting coate...

Superconducting (SC) thin film coatings on Cu substrates are already widely used as an alternative to bulk Nb SRF structures. Using Cu allows improved thermal stability compared to Nb due to having a greater thermal conductivity. Niobium thin film coatings also reduce the amount of Nb required to produce a cavity. The performance of thin film Nb ca...

The production of superconducting coatings for radio frequency (RF) cavities has been developed over several decades. It is widely accepted that for any further improvement in cavity RF performance, innovation is needed and one may have to turn to other forms of Nb and other super-conducting materials. The potential benefits of using materials othe...

The Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany, provides unique possibilities for a new generation of hadron-, nuclear- and atomic physics experiments. The future antiProton ANnihilations at DArmstadt (PANDA or $$\overline{\mathrm{P}}$$ P ¯ ANDA) experiment at FAIR will offer a broad physics programme, covering different...

In Superconducting Radiofrequency accelerating cavities for particle accelerators, the Nb/Cu structure is one of the alternatives to bulk Nb but R&D is required to achieve a reproducible performance that competes with bulk Nb. The DC entry field Hen and critical temperature were studied in the thin Nb films deposited by magnetron sputtering on Cu s...

The study of baryon excitation spectra provides insight into the inner structure of baryons. So far, most of the world-wide efforts have been directed towards N∗ and Δ spectroscopy. Nevertheless, the study of the double and triple strange baryon spectrum provides independent information to the N∗ and Δ spectra. The future antiproton experiment P¯AN...

The antiproton experiment PANDA at FAIR is designed to bring hadron physics to a new level in terms of scope, precision and accuracy. In this work, its unique capability for studies of hyperons is outlined. We discuss ground-state hyperons as diagnostic tools to study non-perturbative aspects of the strong interaction, and fundamental symmetries. N...

In the past few years, it has been established that Laser Ablation Surface Engineering (LASE) is a very effective way of producing surfaces which have Secondary Electron Yields (SEY) < 1. This can be achieved with a variety of laser pulse durations from nano-to picoseconds. However, the features (i.e. moderately deep grooves and nano-particulates)...

The ion induced pressure instability is a phenomenon, which could compromise the performance of positively charged machines. To mitigate this phenomenon, a vacuum system should be properly designed to provide sufficient pumping at correct locations, this includes an accurate gas dynamics modelling of beam vacuum chamber. The gas dynamics model requ...

This paper reports on Monte Carlo simulation results for future measurements of the moduli of time-like proton electromagnetic form factors, $$|G_{E}|$$ | G E | and $$|G_{M}|$$ | G M | , using the $$\bar{p} p \rightarrow \mu ^{+} \mu ^{-}$$ p ¯ p → μ + μ - reaction at $$\overline{\text {P}}\text {ANDA}$$ P ¯ ANDA (FAIR). The electromagnetic form fa...

The study of baryon excitation spectra provides insight into the inner structure of baryons. So far, most of the world-wide efforts have been directed towards N∗ and Δ spectroscopy. Nevertheless, the study of the double and triple strange baryon spectrum provides independent information to the N∗ and Δ spectra. The future antiproton experiment PAND...

Using a thin Nb layer on Copper substrate has several advantages compared with the bulk Nb in construction of Superconducting Radiofrequency accelerating cavities (SRF) for particle accelerators. We were evaluating the properties of two series of Nb layers deposited on Cu substrate, mainly by determining the start of magnetic flux penetration into...

The maximum accelerating gradient of SRF cavities can be increased by raising the field of full flux penetration, H vp . One method which can potentially increase H vp is to use structures consisting of alternating layers of superconductors and insulators (SIS). Magnetometry is commercially available but consists of limitations, such as SQUID measu...

Adhesion of Nb thin film to Cu substrate and size of Nb crystal grains for RF cavities were studied depending on laser intensity and dose. Structures of Nb/Cu, obtained by magnetron sputtering with 500 ˚C (Nr.1) and 700 ˚C (Nr.2) deposition temperature, were irradiated by pulsed Nd:YAG laser. Four areas, irradiated with doses D1=5.6x10²⁰, D2=8.8x10...

Non-evaporable getter (NEG) coating has been used for years in many particle accelerator facilities due to its evenly distributed pumping speed, low thermal outgassing, and low photon and electron stimulated desorption yields. In our earlier work, it has been demonstrated that quaternary Ti–Zr-Hf-V coating deposited from an alloy target in a form o...

EuroCirCol is a conceptual design study of a post-LHC, Future Circular Hadron Collider (FCC-hh) with 50 TeV of beam energy and 100 km long, which aims to expand the current energy and luminosity frontiers. The vacuum chamber of the FCC-hh will have to cope with unprecedented levels of synchrotron radiation power for proton colliders, dealing simult...

PANDA (anti-Proton ANnihiliation at DArmstadt) is planned to be one of the four main experiments at the future international accelerator complex FAIR (Facility for Antiproton and Ion Research) in Darmstadt, Germany. It is going to address fundamental questions of hadron physics and quantum chromodynamics using cooled antiproton beams with a high in...

This chapter highlights just a few most important gas dynamics laws and equations that can be used in the accelerator vacuum modelling. The pressure in a vacuum system with several gases is described by the Dalton law. The chapter shows a few examples to explain how vacuum conductances are used in the modelling of accelerator vacuum system. The vac...

Beam‐induced electron multipacting (BIEM) and electron cloud (e‐cloud) are two coupled effects that can compromise the performance of modern high intensity machines with positively charged beams. Input parameters for the BIEM and e‐cloud phenomena depend on the shape of the vacuum chamber and its surface properties. BIEM in the vacuum chamber cause...

This chapter demonstrates the gas dynamic model describing ion‐induced pressure instability, experimental results that can be used as the input data for modelling, and some examples for room temperature and cryogenic machines. It presents solutions for gas density, stability criteria, and critical current for different boundary conditions, i.e. kno...

This chapter considers two types of cryogenic beam vacuum chamber: a vacuum chamber as a simple cold bore with wall temperature; and a vacuum chamber consisting of a cold bore with wall temperature and a beam screen (or liner) with wall temperature and with pumping slots for desorbed molecules. Gas dynamic models for accelerator cryogenic vacuum ch...

Residual pressure and composition of gas in a closed vacuum volume connected to a working vacuum pump depend on initial conditions, flow rate of gas coming into a vacuum chamber, and layout of vacuum systems. This chapter focuses on the origins of gas molecules in vacuum chamber and how they can be inhibited or reduced. Depending on the demands for...

This book aims to help vacuum scientists and engineers in the gas dynamics modelling of accelerator vacuum systems. It brings together the main considerations which have to be discussed and investigated during modelling and optimisation in a design of particle accelerator vacuum system, as well as to give some analytical solutions that could be use...

This chapter presents an overview of the key concepts related to vacuum. In practice, vacuum specifications for particle accelerators or other large vacuum system are set to minimise the effects of beam‐gas interaction to a tolerable level when their impact on beam parameters is much lower than one from other physical phenomena. Before choosing a p...

The synchrotron radiation (SR) generated by the beam particle from the magnetic components of particle accelerator can irradiate inner surfaces of vacuum chamber and various component inside the accelerator vacuum chamber. In relation to the vacuum design of particle accelerators, there are three main effects that critically affect it. They are pho...

In 1990s a very new approach in vacuum systems for accelerators was invented: the non‐evaporable getter (NEG) coatings. In this approach, an entire surface of vacuum chamber and vacuum components should be coated with NEG film. Since its invention, the development and further optimisation of NEG coating for various applications have been continued....

Parameters of the high intensity accelerators with positively charged beams could be compromised by electron cloud (e-cloud) effect. One of the most efficient mitigation method is providing the beam vacuum chamber walls with low secondary electron yield (SEY). A discovery of low SEY surfaces produced with Laser Ablated Surface Engineering (LASE) br...

Nowadays, one of the main issues of the superconducting thin film resonant cavities is the Cu surface preparation. A better understanding of the impact of copper surface preparation on the morphological, superconductive (SC) and RF properties of the coating, is mandatory in order to improve the performances of superconducting cavities by coating te...

In response to the 2013 Update of the European Strategy for Particle Physics (EPPSU), the Future Circular Collider (FCC) study was launched as a world-wide international collaboration hosted by CERN. The FCC study covered an energy-frontier hadron collider (FCC-hh), a highest-luminosity high-energy lepton collider (FCC-ee), the corresponding 100 km...

In response to the 2013 Update of the European Strategy for Particle Physics (EPPSU), the Future Circular Collider (FCC) study was launched as a world-wide international collaboration hosted by CERN. The FCC study covered an energy-frontier hadron collider (FCC-hh), a highest-luminosity high-energy lepton collider (FCC-ee), the corresponding 100 km...

In response to the 2013 Update of the European Strategy for Particle Physics (EPPSU), the Future Circular Collider (FCC) study was launched as a world-wide international collaboration hosted by CERN. The FCC study covered an energy-frontier hadron collider (FCC-hh), a highest-luminosity high-energy lepton collider (FCC-ee), the corresponding 100 km...

Non-Evap­orable Get­ter (NEG) coat­ing has been used for years in many par­ti­cle ac­cel­er­a­tors due to its ad­van­tages like evenly dis­trib­uted pump­ing speed, low ther­mal out­gassing, and low pho­ton, elec­tron and ion stim­u­lated des­orp­tion yields. Al­though NEG coat­ing has been tested at room tem­per­a­tures in­ten­sively, there is lit...

Developing a surface with low Secondary Electron Yield (SEY) is one of the main ways of mitigating electron cloud and beam-induced electron multipacting in high-energy charged particle accelerators and space-borne RF equipment for communication purposes. In this study we report on the secondary electron yield (SEY) measured from silver coated alumi...

In this study we report on the PVD deposition of Nb3Sn on Cu substrates with and without a thick Nb interlayer to produce Cu/Nb/Nb3Sn and Cu/Nb3Sn multilayer structures. The Nb3Sn was sputtered directly from an alloy target at room and elevated temperatures. The dependence of the superconducting properties of the total structure on deposition param...

Nb superconducting radio-frequency (SRF) cavities are observed to break down and lose their high-Q superconducting properties at accelerating gradients below the limits imposed by theory. The microscopic origins of SRF cavity breakdown are still a matter of some debate. To investigate these microscopic issues, temperature- and power-dependent local...

We review the physics opportunities of the Future Circular Collider, covering its e+e-, pp, ep and heavy ion programmes. We describe the measurement capabilities of each FCC component, addressing the study of electroweak, Higgs and strong interactions, the top quark and flavour, as well as phenomena beyond the Standard Model. We highlight the syner...

In response to the 2013 Update of the European Strategy for Particle Physics, the Future Circular Collider (FCC) study was launched, as an international collaboration hosted by CERN. This study covers a highest-luminosity high-energy lepton collider (FCC-ee) and an energy-frontier hadron collider (FCC-hh), which could, successively, be installed in...

In response to the 2013 Update of the European Strategy for Particle Physics, the Future Circular Collider (FCC) study was launched, as an international collaboration hosted by CERN. This study covers a highest-luminosity high-energy lepton collider (FCC-ee) and an energy-frontier hadron collider (FCC-hh), which could, successively, be installed in...

We review the physics opportunities of the Future Circular Collider, covering its e+e-, pp, ep and heavy ion programmes. We describe the measurement capabilities of each FCC component, addressing the study of electroweak, Higgs and strong interactions, the top quark and flavour, as well as phenomena beyond the Standard Model. We highlight the syner...