The proton microscope design for 9 GeV proton radiography facility is described. Basic principles of proton microscope development are discussed. Two variants of microscope optical scheme are proposed. Simulation of the proton beam dynamics is carried out, the results showing the possibility to obtain the microscope spatial resolution not worse than 10 μ m.

Four quadrupole lenses based on permanent magnets of the NdFeB material (PMQ) were developed for the imaging section for forming images of the ion-optical system of the PRIOR proton microscope prototype: the effective length of two of them is 144 mm, and the other two are 288 mm long. The field induction at the radius of the lens aperture is 1.77 Т, and the aperture is 30 mm in size. The modular design of the PMQ makes it possible to vary the length of the lenses, compensate for the offset of the magnetic axis from the ion optical axis of the microscope channel, and decrease the variation of the angular position of the magnetic medians. The PMQ magnetic field was adjusted, scanned, and its main characteristics were determined. The 3D mathematical models of the magnetic-field distribution that are obtained as a result of PMQ measurements are intended for the use in calculations of the beam dynamics during adjustment of the ion-optical system of the proton microscope and for attaining the highest spatial resolution. The developed lenses were used in the first experiments on the PRIOR facility.

A proton radiography facility with the use of magnetic optics (PUMA proton microscope) has been developed at the TWAC-ITEP accelerator-accumulator facility (the ITEP terawatt accumulator) for measuring the substance density distribution inside static and dynamic objects using the proton beam with an energy of 800 MeV. The proton radiographic image of an object of investigation placed in the object plane of the setup is formed in the plane of the detector with magnification K = 4 with the aid of the magneto-optical system consisting of four quadrupole lenses on permanent magnets. The PUMA facility is intended for measuring objects with an areal density of up to 20 g/cm 2 with a field of vision as large as 20 mm in diameter. The spatial resolution of radiographic images depends strongly on the areal density of the object of investigation. For the PUMA facility, the spatial resolution varies from 60 to 115 μm at an areal density of 0.46–17 g/cm 2 , respectively. The dynamical state of substance can be investigated in four consecutive radiographic images, since the time structure of the proton beam consists of four pulses, each with a duration of 47 ns (full width at half maximum (FWHM)) and an interval of 250 ns between them. This article is devoted to the description of the proton microscope construction. The main metrological characteristics of the facility are described using experiments with static and dynamic objects as an example.

Summary form only given. Proton radiography facility which uses magnetic optics (proton microscope PUMA [2]) was developed at TWAC-ITEP accelerator[1]. PUMA proton microscopy facility was specially designed for studies in the field of high energy density physics, including the research of equations of state and phase transitions of matter at extreme conditions, shockwave and detonation physics, hydrodynamics of high energy density flows, and dynamic material strength and damage studies [3]. Proton microscope PUMA allows the measurement of density distribution within static and dynamic objects by using proton beam with energy 800MeV. Proton-radiographic image of the object is formed in the plane of the detector with magnification k=4. An image of the object is formed using a magneto-optical system consisting of four quadrapole lenses on permanent magnets (PMQ). PUMA facility is designed for the measurement of objects with areal density of 20 g/cm2 with field of view of 20 mm. The spatial resolution of radiographic images depends strongly on the areal density. For PUMA facility, spatial resolution is from 60 microns to 115 microns for areal density of objects from 0.46 g/cm2 to 17 g/cm2, respectively. The term structure of the proton beam consists of four pulses of 47 ns (FWHM), each at an interval of 250 ns. This allows investigating the dynamical state of matter in four consecutive radiographic images. Research was also performed on nondestructive testing of static objects (including tomographic methods) and radiobiological research.

Laser interferometry methods were used to measure the density of free electrons and degree of plasma ionization in a hydrogen target intended for experiments on determining energy losses of heavy ion beams in an ionized matter. It is shown that the linear electron density can be varied in the range from 3.3 × 10 17 to 1.3 × 10 18 cm −2 by varying the initial plasma parameters (the hydrogen pressure in the target and the discharge current). The error in measuring the linear electron density in the entire range of the varied plasma parameters was less than 1%. The maximum degree of plasma ionization achieved at the initial gas pressure of 1 mbar was 0.62 ± 0.05.

In recent years studies of shock and detonation wave phenomena at extreme dynamic conditions were performed at proton radiography facility developed at the 800 MeV proton beam line of ITEP Terawatt Accelerator (ITEP-TWAC). The facility provides a multi-frame imaging capability at 50 μm spatial and 70 ns temporal resolution. The results of latest studies conducted there are presented, including explosion and detonation of pressed and emulsion high explosives, shock-induced dense non-ideal plasma of argon and xenon and shock loading of non-uniform metal surfaces. New compact explosive generators developed specifically for a use at proton radiography facilities are also presented.

Приведены результаты разработки лазерного интерферометра, предназначенного для измерения массовой скорости конденсированных веществ в ударно-волновых экспериментах в области физики высоких плотностей энергии. Интерферометр интегрирован в состав измерительного комплекса протонно-радиографической установки ТВН-ИТЭФ. Разработанная лазерная система позволяет измерять скорости свободной поверхности образцов в ударно-волновых экспериментах с погрешностью не хуже 10 м/с во всем диапазоне достигаемых в эксперименте скоростей. Временное разрешение измерений ограничивается быстродействием используемых ф.э.у. и составляет 2.5 нс. Проведены совместные исследования методами протонной радиографии и лазерной интерферометрии ударно-волнового нагружения металлических мишеней, процессов откольного разрушения и струеобразования на свободных поверхностях в металлах.

The results of development of a laser interferometer designed for measuring the mass velocity of condensed substances in shock-wave experiments in the field of high-energy-density physics are presented. The interferometer is incorporated in the measuring complex of the TWAC-ITEP proton-radiographic facility. The developed laser system allows measurements of the velocity of free surfaces of samples in shock-wave experiments with an error no worse than 10 m/s for the entire range of velocities attained experimentally. The time resolution of measurements is limited by the response speed of the used PMTs and amounts to 2.5 ns. Combined investigations of shock-wave loading of metal targets and scabbing-fracture and jet-formation processes on free metal surfaces were performed by the proton-radiography and laser-interferometry methods.

Приведены результаты разработки бесконтактной дистанционной методики исследования теплофизических характеристик конденсированного вещества при импульсном воздействии интенсивным пучком тяжелых ионов. Методика основана на измерении скорости звука по времени прохождения зондирующего оптоакустического импульса в мишени, находящейся под воздействием ионного пучка. Для регистрации акустического отклика разработана шлирен-система, в основу которой положена теневая методика визуализации оптических фазовых неоднородностей. Работоспособность методики проверена в тестовых экспериментах на установке ТВН-ИТЭФ.

A new setup for the experimental investigation of rapid dynamic processes using proton radiography techniques has been created at the TWAC-ITEP terawatt accelerator-accumulator facility. A set of equipment for conducting shock-wave experiments has been designed, constructed, and tested, and an instrumentation-software complex has been developed for the automation of experiments. The first series of experiments with dynamic targets representing high explosives have been carried out, in which the density distribution in detonation waves initiated in these explosives has been measured.

The integrated automation system (IAS) for proton radiography and ion radiobiological experiments on the fast extraction beamline of the TWAC-ITEP accelerator-accumulator facility has been developed and successfully used. The subsystems that are parts of the IAS perform the following functions: acquisition, storage, and processing of experimental data; control of the magnetic lenses of the charged-particle beam transport line; beam diagnostics; and radiation safety and monitoring. The subsystems are composed of hardware-software modules, each dealing with a particular measuring or actuating device and a program for readout, storing, and processing of experimental data corresponding to this device. The modules communicate via a TCP/IP socket in a configuration dependent on the requirements of a particular experiment. Data are transmitted from one module to the other in the real time mode within the closed ring network, which allows consecutive processing of incoming experimental data. The status of the system elements, incoming experimental data, and results of their rapid analysis are displayed in the real time mode on the web server. Owing to the flexible structure of the integrated automation system, it is possible to promptly create new configurations for acquisition and processing of experimental data.

The results of the development of a contactless remote technique for studying thermal characteristics of condensed matter under a pulsed action of an intense heavy-ion beam are presented. This technique is based on measuring the velocity of sound from the time of passage of a probing optoacoustic pulse in a target exposed to an ion beam. To record an acoustic response, we have developed a schlieren system based on the shadow technique for visualizing optical phase nonuniformities. The efficiency of this technique was checked in test experiments on the TWAC-ITEP facility.

The 800MeV proton radiography facility for high dynamic pressure research in condensed matter has been commissioned at the Terrawatt Accelerator of Institute of Theoretical and Experimental Physics (TWAC-ITEP) in Moscow. Spatial resolution of the facility measured in static experiments with a variety of test objects was found to be 0.30 +/- 0.01mm in current experimental arrangement. First dynamic experiments on the observation of a shock loading of steel surface and a propagation of the detonation wave in a high explosive charge were conducted. Good quantitative agreement of density profiles reconstructed from obtained radiographic images with theoretical and simulated data showed the capabilities of high energy ion beam radiography as an excellent tool for bulk density measurements in high dynamic pressure studies.

На быстром выводе пучка частиц ускорительно-накопительного комплекса ТВН–ИТЭФ создана и успешно эксплуатируется комплексная система автоматизации экспериментов по протонной радиографии и ионной радиобиологии. В состав комплекса входят следующие подсистемы: сбора, обработки и сохранения экспериментальных данных; управления магнитными элементами линии транспортировки пучка заряженных частиц; диагностики пучка; контроля радиационного фона и безопасности. Подсистемы представляют собой наборы аппаратно-программных модулей, каждый из которых обслуживает измерительный или исполнительный прибор и соответствующую ему программу считывания, сохранения и обработки экспериментальных данных. Модули соединяются посредством протокола TCP/IP socket в конфигурации в зависимости от требований эксперимента. Данные от модуля к модулю передаются в режиме реального времени в рамках замкнутой кольцевой сети, что позволяет последовательно обрабатывать поступающие экспериментальные данные. Состояние элементов системы, а также поступающие экспериментальные данные и результаты их экспресс-анализа отображаются в режиме реального времени и сохраняются на интернет-сервере. Гибкая структура комплексной системы позволяет оперативно создавать новые конфигурация сбора и обработки экспериментальных данных.

Parameters of the proton radiographic facility which constructed on the ITEP TWAC accelerator for diagnostic static objects and fast process are reported. Time structure of accelerator beam is able to make a diagnostic of dynamic process with characteristic speed up to 20 km/s.