Diagnostic Equipment of High-current Pulsed Ion Beams A

Diagnostic Equipment of High-current Pulsed Ion Beams A. Pushkarev Tomsk Polytechnic University, Russia 1. Faraday cup 2. Time-of-flight diagnostics 3. Thomson Parabola spectrometer 4. Thermal imaging diagnostics of powerful ion beams 5. Acoustic diagnostics 6. Pin-diode 7. Measurement of ion beam divergence 8. Analysis of correctness of diagnostic of high current pulsed ion beam by ion current density 1

Ablation plasma Action mechanism of ion beam Melt region Stress wave 1 -5 J/cm 2 108 -109 К/с A HPIB Stress wave Ion range 1 -2 mkm 2

Пьезоэлектрический эффект Пьезоэлектри ческий эффе кт — эффект возникновения поляризации диэлектрика под действием механических напряжений (прямой пьезоэлектрический эффект). Пьезоэлектрики – вещества (диэлектрики и полупроводники), в которых при упругих деформациях возникает вынужденная электрическая поляризация – прямой пьезоэффект. Следствие прямого пьезоэффекта – обратный пьезоэффект – появление механических деформаций под действием электрического поля. При упругой деформации происходит смещение положительных и отрицательных ионов друг относительно друга, что приводит к возникновению электрического момента. Пьезоэффекты наблюдаются только в кристаллах, не имеющих центра симметрии. К пьезоэлектрикам относятся, например, кварц, кристаллы дигидрофосфата калия KH 2 PO 4, различные виды пьезокерамики и др. Пьезоэлектрики находят применение в качестве мощных излучателей, приемников и источников ультразвука, стабилизаторов частоты, электрических фильтров высоких и низких частот, трансформаторов напряжения и тока 3

Z. H. Dong, C. Liu, X. G. Han, M. K. Lei Induced stress wave on the materials surface irradiated by high-intensity pulsed ion beam // Surface & Coatings Technology 201 (2007) 5054– 5058 A schematic drawing of the device for dynamical measurement of stress wave. The waveforms of measured induced stress in pure Ti irradiated by HIPIB at an ion current density of 350 A/cm 2. 4

Зависимость амплитуды волны сжатия от плотности ионного тока 5

Xiaoyun Le, Xiaoping Zhou, Sha Yan, Zhijian Liu, Weijiang Zhao. Detection of Shocks Generated by the Irradiation of Nanosecond Intense Pulsed Ion Beam and Electron Beam // 15 International Symposium on High Current Electronics: Proceedings. Tomsk: Publishing house of the IAO SB RAS, 2008. 545 pp. Schematic diagram of PVDF detecting system Shock signal induced by IPIB of TEMP II Xiaoyun Le, Sha Yan, Zhijian Liu, Weijiang Zhao Detection of shocks generated by intense pulsed ion 6 beam irradiation // Surface & Coatings Technology 01/2007; 201(9): 4991 -4994

X. P. Zhu, F. G. Zhang, Y. Tang, J. P. Xin, M. K. Lei Dynamic response of metals under high-intensity pulsed ion beam irradiation for surface modification // Nuclear Instruments and Methods in Physics Research B 272 (2012) 454– 457 Illustration of space–time diagram for the processes of stress wave generation and propagation in titanium target under HIPIB irradiation. Stress waves for the titanium targets of 3 mm thickness irradiated at the different ion current densities of 200– 400 A/cm 2, respectively. 7

Проволочный дозиметр для измерения характеристик электронных пучков Дозиметр с рабочим телом в виде плоского меандра. Типичный выходной сигнал (t), который пропорционален распределению поглощенной энергии в прямолинейных секциях дозиметра Залюбовский И. И. , Калиниченко А. И. , Лазурик В. Т. , Введение в радиационную акустику, Издательство при Харьковском государственном университете издательского объединения «Вища Школа» , Харьков, 1986. 167 с. 8

The acoustic diagnostics of a pulse ion beam sensor 5 m Scheme of generation and recording of acoustic waves zoom in Waveforms of the signal measured by PZT Pushkarev A. I. , Isakova Yu. I. , Xiao Yu, Khailov I. P. Characterization of intense ion beam energy density and beam induced pressure on the target with acoustic diagnostics // Review of Scientific Instruments, 2013, vol. 9 84, iss. 8, 083304 (2013)

The delay of the acoustic signal in the copper tavern length of 5 meters. At a delay of 1. 36 ms of the acoustic signal in the tavern 5 meters velocity of propagation of acoustic waves is equal to 3680 m / sec. Задержка акустического сигнала в медной шинке длиной 2. 7 метров. При задержке акустического сигнала 0. 77 мсек в шинке длиной 2. 7 метров скорость распространения акустических волн равна 3510 м/сек. Табличные данные для меди 3500 -3700 м/сек.

The shape of the acoustic signal The signal from the piezoelectric transducer. Tavern 2 × 5 mm, length 2. 7 meters. Two pulses. A piezosensor signal while ion beam radiation with the different energy density

Calibration of the piezosensor on energy density Thermal imprint of the beam on the target (a) placed behind the strip and the cross sectional distribution of the beam energy density (b) in vertical (1) and horizontal (2) cross section 12

A piezosensor signal while ion beam radiation with the different energy density

Results of calibration melting Cu 1356 K J= 2 J/cm 2 The calibration dependence of the PZT signal amplitude on the ion energy density The temperature distribution in copper target irradiated with C+ ions at different times after interception with the beam The simulation was made using the Comsol Multiphysics program for the following parameters: pulse duration of 100 ns and ion beam energy density of 2 J/cm 2. Phase transformation was not taken into account.

The results of statistical analysis Shot-to-shot variation in the energy density for 35 shots with a 120 second time interval between shots (a), with a 10 sec interval using acoustic diagnostics (b) The results of statistical analysis of the beam energy density reproducibility in a self-magnetically insulated ion diode showed that the standard deviation of the energy density at a high repetition rate (time interval between measurements of 10 sec) does not exceed 11%, 15

Calibration of the piezosensor by the drop calibration method A piezoeffect is characterized by a piezomodulus d: where q is an occurring charge, F is a modulus of a force, C is a piezosensor capacity, U(t) is a recorded potential difference in the piezosensor electrodes Then, a force is connected with a recorded voltage by the relation: k is a coefficient of the piezosensor sensitivity, N/V 16

The coefficient of the piezosensor sensitivity is equal to: where a is the acceleration, m is a lading weight, v is the lading velocity change for time ∆t. With the piezosensor calibration lading hung on a hair, falls down from the height h, hitting on the transducer end surface. At this time the lading velocity changes from maximum to zero, and this velocity change is equal to the lading velocity in the lowest point. It can be determined with the help of the energy conservation law. There after, we can get: In general, with the velocity change, influencing on the piezosensor (and correspondingly recorded voltage): 17

A piezosensor signal while the calibration by lading with the mass of 50 grams, with the lading lifting on 12 mm (1), 50 mm (2), 80 mm (3). In the course of calibration we rated the integral of the second positive signal half-wave, coming from the piezosensor, like in the course of getting calibration piezosensor signal amplitude dependence on PIB energy density. The value of the piezosensor sensitivity for the series of 10 measurements 44± 7 k. N/V. 18

With PIB absorption in the target an increased pressure zone appears. This zone forms acoustic oscillations. A pressure value is equal to: where S is the area of the copper wire radiation by an ion beam, equal to 7× 50 mm 2. Dependence of maximum pressure in the zone of PIB absorption on the energy density 19

Dependence of maximum beam generated pressure in the target on the input energy density Target – Al. Ion beam (660 ke. V, 120 ns), containing C+ ions (40%) and protons. Target – Ti. Ion beam 350 ke. V, 200 -400 A/cm 2, 150 ns, H+. Target – Cu. Ion beam (660 ke. V, 120 ns), containing C+ ions (40%) and protons. Pushkarev A. I. , Isakova Yu. I. , Xiao Yu, Khailov I. P. Characterization of intense ion beam energy density and beam induced pressure on the target with acoustic diagnostics // Review of Scientific Instruments, 2013, vol. 20 84, iss. 8, 083304 (2013)

Investigation of energy density distribution over cross-section beam distance =3600 m/s × t The comparison of the form of PZT signal (2) with that of the energy density distribution over 21 the cross section measured using infrared imaging diagnostics (1)

Scheme measuring sound waves generated by the IPI signal from the piezoelectric transducer and the two pulse. Shank portion is closed with tape.

Acoustic diagnostics of a pulsed electron beam Oscillograms for different beam profiles: 1 - without absorber; 2 - with the absorber. Scheme screening the central part of the beam

Diagnostic Equipment of High-current Pulsed Ion Beams A. Pushkarev Tomsk Polytechnic University, Russia 1. Faraday cup 2. Time-of-flight diagnostics 3. Thomson Parabola spectrometer 4. Thermal imaging diagnostics of powerful ion beams 5. Acoustic diagnostics 6. Pin-diode 7. Measurement of ion beam divergence 8. Analysis of correctness of diagnostic of high current pulsed ion beam by ion current density 24

5. Pin-diode Electrical circuit of the PIN-diode diagnostics

Spiral ion diode Photo of the diode chamber, waveform of the power supplied to the diode, and a signal from the pin-diode 26

Photo of the diode chamber, waveform of the power supplied to the diode, and a signal from the pin-diode 27