Search

The hard X-ray free-electron laser at the Pohang Accelerator Laboratory (PAL-XFEL) in the Republic of Korea achieved saturation of a 0.144 nm free-electron laser beam on 27 November 2016, making it the third hard X-ray free-electron laser in the world, following the demonstrations of the Linac Coherent Light Source (LCLS) and the SPring-8 Angstrom Compact Free Electron Laser (SACLA). The use of electron-beam-based alignment incorporating undulator radiation spectrum analysis has allowed reliable operation of PAL-XFEL with unprecedented temporal stability and dispersion-free orbits. In particular, a timing jitter of just 20 fs for the free-electron laser photon beam is consistently achieved due to the use of a state-of-the-art design of the electron linear accelerator and electron-beam-based alignment. The low timing jitter of the electron beam makes it possible to observe Bi(111) phonon dynamics without the need for timing-jitter correction, indicating that PAL-XFEL will be an extremely useful tool for hard X-ray time-resolved experiments. The Pohang Accelerator Laboratory X-ray Free Electron Laser (PAL-XFEL) in South Korea has now entered operation with a timing jitter of just 20 fs.

The hard XFEL operation procedure established at PAL-XFEL using e-BBA and incorporating undulator radiation spectrum analysis proved to be highly reliable and robust, and essential for the variable-gap undulators. The state-of-the-art design of the electron linear accelerator along with the reliable FEL lasing procedure has allowed reliable operation of PAL-XFEL with unprecedented stability in terms of orbit, energy, and timing; FEL position stability: 8 ~ 9% of beam size, FEL power stability: ~ 4.0% rms, FEL timing jitter: < 20 fs, which can obviously make users’ experiments more successful. And the undulator optics matching using the wire-scanner-based emittance measurement is extensively used to maximize the FEL intensity even at higher photon energy up to 14.5 keV, which is the brightest FEL at this photon energy that has ever been achieved in the world.

A very stable (≤10 ppm) magnet power supply (MPS) is required in an accelerator to achieve acceptable beam dynamics. Many factors affect the stability of an MPS, so design of the MPS requires much attention to noise-reduction schemes and to good processing of the signals from the feedback stage. This paper describes some design considerations for an MPS installed and operated in the Pohang Accelerator Laboratory: (1) control method, (2) oversampling technology, (3) ground isolation between hardware modules and (4) low-pass filter design to reduce the switching noise and rectifier ripple components, and shows the stability of three designed devices. The MPS design considerations were verified and validated in simulations and experiments. This paper also shows the relationship between stability and measurement aperture time of digital voltage meter 3458 A to measure stability of a current.

PAL-XFEL utilizes a three-chicane bunch compression (3-BC) scheme (the very first of its kind in operation) for free-electron laser (FEL) operation. The addition of a third bunch compressor allows for more effective mitigation of coherent synchrotron radiation during bunch compression and an increased flexibility of system configuration. Start-to-end simulations of the effects of radiofrequency jitter on the electron beam performance show that using the 3-BC scheme leads to better performance compared with the two-chicane bunch compression scheme. Together with the high performance of the linac radiofrequency system, it enables reliable operation of PAL-XFEL with unprecedented stability in terms of arrival timing, pointing and intensity; an arrival timing jitter of better than 15 fs, a transverse position jitter of smaller than 10% of the photon beam size, and an FEL intensity jitter of smaller than 5% are consistently achieved.

In this paper, we introduce two classes of optimal codes, [, k, ] simplex codes and [, k, ] codes, attaining Griesmer bound with equality. We further present and compare the locality of them. The [, k, ] codes have good locality property as well as optimal code length with given code dimension and minimum distance. Therefore, we expect that [, k, ] codes can be applied to various distributed storage systems.

In this paper, we analyze the statistical characteristic and describe the anti-interference performance of the signal for the LPI-applied GNSS using encrypted spreading code. To do this, we analyze the correlation property of encrypted sequences theoretically having various symbol sets over complex root of unity. We derive the degradation of anti-interference performance of encrypted sequences comparing with Gold and Zadoff-Chu sequences using theoretical and experimental methods. ※ 본 연구는 방위사업청과 국방과학연구소가 지원하는 국방위성항법특화연구센터 사업의 일환으로 수행되었습니다. First Author : Yonsei University Department of Electrical and Electronic Engineering, kh.park@yonsei.ac.kr, 학생회원 ° Corresponding Author : Yonsei University Department of Electrical and Electronic Engineering, hysong@yonsei.ac.kr, 종신회원 * Yonsei University Department of Electrical and Electronic Engineering, mk.song@yonsei.ac.kr ** Agency for Defence Development, flukelee@add.re.kr, 정회원 논문번호:KICS2014-12-497, Received December 22, 2014; Revised February 11, 2015; Accepted February 11, 2015 I. 서 론 통신 사용자의 위치정보 제공을 위해 설계된 항법 신호는 실생활의 많은 곳에서 응용되고 있다. 특히 위 치정보가 명확하고 측위반경이 넓은 위성을 이용한 전지구 위성항법시스템(Global Navigation Satellite System, GNSS)는 우리나라에서도 널리 쓰이는 미국 의 GPS 를 비롯하여 유럽의 Galileo, 러시아의 GLONASS, 중국의 Beidou 등의 명칭으로 각국에서 활발하게 연구되는 분야이다. 최근 우리나라에서도 독 자적 항법기술을 확보하기 위한 연구가 활발히 진행 되고 있다. 가장 먼저 상용화된 미국의 GPS의 경우 신호탈취 및 변조에 의한 피해가 다수 보고되고 있으며 , 재밍 신호를 통한 신호방해 공격은 우리나라에서도 수차례 보고되었을 만큼 공격에 취약한 실정이다. 따라서 논문 / 저피탐 위성항법 신호 설계를 위한 암호화된 확산부호의 상관 특성에 관한 연구 265 그림 1. 위성항법신호의 구조 Fig. 1. Structure of Navigation Satellite System Signal 상용화된 위성항법신호를 군용 항법시스템으로 도입 하기 위해 항법신호를 보호하는 방법이 연구되기 시 작하였고, 국내에서도 위성항법신호의 항재밍 성능 향 상을 위한 다양한 시도가 이루어졌다 . 특히 기존에 레이더 신호 등에서 사용되던 저피탐 기법에 대한 연구가 진행되었는데, 이는 신호의 탐지를 어렵게 하 여 신호 생성 레벨에서 신호공격으로부터 신호를 보 호하는 기술이다. 군사 목적으로 항법신호의 보호가 고려되어 설계된 GPS P(Y) 부호 [1] 및 전문화된 군용 항법신호로 설계 된 GPS M 부호와 Galileo의 정부 서비스 신호인 Galileo E6의 경우 항법신호의 확산부호에 암호화 를 도입함으로써 공격자가 신호를 획득하기 어렵게 하고 있다. 하지만 실제 이렇게 암호화된 확산부호를 사용하는 경우 항법신호의 측위성능을 결정하는 확산 부호의 자기/상호상관 특성은 상관특성을 극대화하여 설계된 Gold 부호 등을 사용하는 것에 비하여 상당히 감소하는 것으로 추측할 수 있다. 그러나 암호화에 따 른 측위성능의 변화나 공격에 대한 내성 정도의 분석 에 대한 국내 연구는 미비한 실정이다. 또한 항법신호를 위한 확산부호로 기존의 2진 수열 이 신호가 아닌 복소수 값을 가지는 Zadoff-Chu 수열 을 사용하는 시스템이 제시 되었고 다양한 후보코드 간 간섭성능 분석에 대한 연구가 이루어졌다. 하지 만 복소수 수열을 기반으로 한 암호화된 확산부호의 성능에 대한 분석은 거의 이루어지지 않고 있다. 본 논문에서는 다양한 복소 단위원 심볼 환경에서 암호화된 확산부호가 적용된 항법신호의 상관특성을 기존 확산부호가 적용된 항법신호의 상관특성과 비교/ 분석하고 실제 암호화로 인한 측위성능 저하 정도를 이론적/실험적으로 규명한다.

[Purpose] The objective of this study was to examine the effect of step climbing exercise on the walking ability of stroke patients. [Subjects and Methods] Among hospitalized stroke patients, 24 were selected based on the study criteria and randomly divided into two groups: an experimental group (12 patients) and a control group (12 patients). The patients in both groups participated in 15-minute exercise sessions three times a week for eight weeks. To analyze the effect of the exercise, muscle strength, the Timed Up and Go test, and step length were measured before and after the exercise. [Results] step climbing exercise improved the muscle strength in the lower limbs of the stroke patients, as well as their Timed Up and Go results and step lengths. [Conclusion] The effects were similar to a stair gait exercise, and thus, step climbing may be more broadly applied to the treatment of stroke patients.

In this paper, we derive the average repair bandwidth and/or read cost for arbitrary repairable linear code ensembles. The repair bandwidth and read cost are the required amount of data and access number of nodes to restore a failed node, respectively. Here, the repairable linear code ensemble is given by such parameters as the number  of data symbols, the number  of parity symbols, and their degree distributions. We further assume that the code is systematic, and no other constraint is assumed, except possibly that the exact repair could be done by the parity check-sum relation with fully connected   storages. This enables one to apply the result of this paper directly to any randomly constructed codes with the above parameters, such as linear fountain codes. The final expression of the average repair read cost shows that it is highly dependent on the degree distribution of parity symbols, and also the values  and . ※ This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education(No. 2013R1A1A2062061). First Author : School of Electrical and Electronic Engineering, Yonsei University, js.park09@yonsei.ac.kr, 학생회원 ° Corresponding Author : School of Electrical and Electronic Engineering, Yonsei University, hysong@yonsei.ac.kr, 종신회원 * School of Electrical and Electronic Engineering, Yonsei University, jh.kim06@yonsei.ac.kr, kh.park@yonsei.ac.kr, 학생회원 논문번호:KICS2014-08-333, Received August 30, 2014; Revised November 6, 2014; Accepted November 6, 2014 I. 서 론 최근, 국내외에서 클라우드 서비스에 대한 연구 뿐만 아니라, 분산 저장 시스템(Distributed storage system, DSS)을 위한 소실 부호 기술(Erasure coding) 이 클라우드 서비스 제공자들과 연구자들의 관심을 끌고 있다 . DSS를 위한 부호 기법의 주요한 두가 지 성능 척도는 필요 저장 공간과 하나의 저장소가 소 The Journal of Korean Institute of Communications and Information Sciences '14-11 Vol.39B No.11 724 그림 1. 시스터메틱 선형 부호의 일반적인 그래프 포현 Fig. 1. Graph representation of a systematic linear code 실되었을 때 이를 복구하기 위해 필요한 대역폭(즉, 데이터의 양)이다. 이 두가지 척도에 대한 바운드가 잘 알려져 있는데, 어떤 부호가 그 바운드를 만족하면 최적이라 한다 . 또한 두 척도에 대한 양극단의 최적 지점을 만족하는 부호를 각각 최소 저장 용량 재생 (Minimum storage regenerating, MSR) 부호, 최소 복 구 대역폭 재생(Minimum bandwidth regenerating, MBR) 부호라 한다. 기존의 소실 부호에 대한 연구 [8] 는 이진 소실채널에서 DSS를 고려하지 않고 진행되 었으나, 최근에는 DSS를 위해 최적 및 극단 지점을 만족하도록 설계된 repair-by-transfer 부호 , product-matrix 알고리즘, 그리고 최대 거리 분리가 능(Maximum distance separable, MDS) 부호 [5] 등이 제안되었다. 바운드의 중간 부분에 대한 재생 부호 (Regenerating codes) 또한 실제적으로 중요한데, 이 러한 관점에서 부분성(Locality) 개념이 도입되었다. 만약 어떤 저장소가 소실되어 새로운 저장소에 복구 해 놓아야 하는 경우, 전체 데이터 심볼 수 대비 훨씬 적은 양의 저장소만 접속하여 복구할 수 있으면 부분 접속으로 복호 가능(Locally decodable)하다고 부른다 . 그러한 부호를 부분접속 복구 부호(Locally repairable code, LRC) 라 하는데, 이에 대한 간단하 며 실용적인 연구가 있었으며 부호 파라미터와 부분성에 연구가 진행되었다 . 또한 저장 공간과 부분성에 대한 trade-off를 주는 피라미드 부호가 제안 되었으며, 자연적으로 부분접속 복구 성질을 갖는 파운틴 부호에 대한 near-MDS 성질의 연구가 발표되 었다 . 또한, 복구를 위한 접속 노드 수를 줄일 수 있 는 간섭 정렬(Interference alignment, IA) 기법이 발표되었다. 본 논문에서는 선형 재생 부호 앙상블의 평균 복구 접속 비용과 대역폭을 유도한다. 우리는 평균 복구 접 속 비용, 즉 하나의 소실 저장소를 복구하기 위해 필 요한 다른 저장소 접속 수를 주로 고려하며 이로부터 복구 대역폭을 쉽게 유도할 수 있다. 필요한 입력 파 라미터로는 데이터 심볼의 수 , 패리티 심볼의 수  , 그리고 그들의 차수 분포이다. 각 패리티 심볼은 데이터 심볼들의 선형 결합으로 만들어지며,  개의 부호 심볼들은 개의 저장소에 각각 저장되며 모든 저장소는 연결되어있다고 가정하자. 이 때, 패리티 심볼과 데이터 심볼간 연관성은 차수 분포 를 제외하고는 특정짓지 않도록 한다. 이러한 가정은 본 논문의 가정을 재생 파운틴 부호 [13] 등에 직접 적 용 가능하게 한다. 본 논문은 II장에서 선형 재생 부호를 간략히 설명 하고, III장에서는 주 결과인 평균 복구 접속 비용과 대역폭을 유도한다. 마지막 IV장에서는 시뮬레이션 결과들과 결론으로 논문을 마친다.

This study presents a new carrier-based hybrid pulse width modulation (PWM) Method for the cascaded capacitor-clamp multilevel inverter (CCCMLI), which combines the benefits of a new alternative level-shifted carrier PWM and a phase-shifted carrier PWM. For modulating the CCCMLI, the phase disposition sub-harmonic PWM was first proposed, but does not show good performances in an even load sharing between inverter cells connected in series, flying-capacitor voltage balancing and output waveform quality. On the other hand, a proposed PWM method enables to achieve a balanced load sharing between cascaded cells even at low amplitude modulation indices as well as the excellent voltage balancing control of the flying-capacitors with a much smaller voltage ripple and the good harmonic characteristics in output waveforms. The proposed modulation is verified through both simulation and field-programmable gate array (FPGA) based experimental results.

Speed sensorless modes of operation are becoming standard solution in the area of electric drives. This paper presents flux estimator and speed estimator for the speed sensorless vector control of induction motors. The proposed sensorless methods are based on the model reference adaptive system (MRAS) observer and adaptive speed observer (ASO). The proposed speed estimation algorithm can be employed in the power control of grid connected induction generator for wind power applications. Two proposed schemes are verified through computer simulation PSIM and compared their simulation results.

The subject were randomly allocated to three groups: ankle strategy exercise (group A), balance exercise (group B) and control (group C). Group A was received the conventional physical therapy plus ankle strategy exercises for 20 minutes in one session. Group B was received the same conventional physical therapy plus balance exercises for 20 minutes in one session. Two active groups were performed in the session 3 times a week, for a total of 6 weeks. and Group C was only received the same conventional physical therapy.Balance test was assessed using center of pressure (COP) in the anteroposterior (A-P), mediolateral (M-L) direction, Berg balance scale (BBS) and Timed Up and Go Test (TUG).

In this paper, we introduce basic theories, effects and applications of the unequal error protection (UEP) system that is expected to play a major role in the future multi-layered broadcast system. Also we show results of surveys on the various previous studies and standards about the UEP systems, and we give prospects of standardizations and future applications of UEP based on the surveys.

A magnetic field measurement instrument for compact cyclotrons has been developed. Forty-eight Hall sensors are used for magnetic measurements, and a set of four Hall sensors is allocated to each channel. The magnetic field and the offset are tabulated with a permanent 4,500-G magnet. The measurement device is made to be thin, long, and rectangular, to overcome the narrow gap between upper and lower hills in a compact cyclotron (2 ∼ 3 cm). This instrument measures a magnetic field signal in the unit of Tesla and transforms it to a voltage signal as an output. The instrument has a 0.1-percent field-measurement stability margin and can be used to measure the magnetic field produced by a 9-MeV cyclotron magnet.

See paper for full list of authors; The Korea Rare Isotope Accelerator, currently referred to as KoRIA, is briefly presented. The KoRIA facility is aimed to enable cutting-edge sciences in a wide range of fields. It consists of a 70 kW isotope separator on-line (ISOL) facility driven by a 70 MeV, 1 mA proton cyclotron and a 400 kW in-flight fragmentation (IFF) facility. The ISOL facility uses a superconducting (SC) linac for post-acceleration of rare isotopes up to about 18 MeV/u, while the SC linac of IFF facility is capable of accelerating uranium beams up to 200 MeV/u, 8 pμA and proton beams up to 600 MeV, 660 μA. Overall features of the KoRIA facility are presented with a focus on the accelerator design.

This paper presents a high-resolution voltage reference which is suitable for building high-precision magnet power supplies for accelerators. It consists of digital signal processor, field programmable gate array, and two digital-to-analog converter (DAC) boards. The DAC board uses two commercial 16-bit-D/A converters and an analog signal processing circuit to achieve a resolution higher than 20-bit. The proposed voltage reference has a resolution of 20-bit (1 ppm) for the +10 V full scale. The short- and long-term stabilities are ~1 and 5 ppm, respectively. The controllability and reproducibility of the output voltage to a step input were ~1 ppm (10 μV). The equivalent bandwidth of the voltage reference was ~5 kHz. These experimental results show that the proposed voltage reference may be applied to many other systems which require a high-resolution and cost-effective voltage reference with a good long-term stability. The voltage reference can be interfaced with the Ethernet (including EPICS), CAN, and RS232C.

In this paper, A novel control scheme of LLC resonant converter is proposed to maximize energy harvest of photovoltaic resources by adapting an integrated transformer with variable magnetizing inductance adaptively. The proposed resonant converter changes its magnetizing inductance according to the PV panel operating condition, and thus it is possible to achieve a minimum circulating energy under wide input voltage range by the appropriate DC gain of the resonant tank. In addition, the proposed method introduces the feedback loop based on the switching frequency to regulate the magnetizing inductance, and as a result, those advantages can be easily obtained in even wide output power levels. The operating principles of the proposed converter and its control structure are explained in detail, and the design example of a 250-W converter is also presented by using the fundamental harmonic analysis. Several simulation results under various conditions of PV source and output power levels are provided in order to verify its effectiveness.

Pohang Accelerator Laboratory (PAL) is developing a 0.1 nm SASE based FEL based on 10 GeV S-band linear accelerator named PAL-XFEL. At the first stage, PAL-XFEL needs two undulator lines for photon source. The hard Xray undulator line requires 18 units of 5 m long hybrid-type conventional planar undulator and soft X-ray line requires 6 units of 5 m long hybrid type planar undulator with additional few EPUs for final polarization control. PAL is developing undulator magnetic structure based on EU-XFEL concepts. The key parameters are min pole gap of 8.3 mm, with period length 26 mm (HXU), 35 mm (SXU), and 5.0 m magnetic length. . In this report, the prototyping, and the development of pole tuning procedure, the impact of the background field error, and the effects of the girder bending on the optical phase error will be presented.

This paper presents a Hall probe mapping system for measuring a cyclotron magnet, which has been fabricated for the 13 MeV cyclotron at the Korea Institute of Radiological and Medical Sciences. Two Hall probes are mounted on a precision mechanical x – y stage and map magnetic field in the Cartesian coordinate system. The mapping system uses the ‘flying’ mode field mapping method to reduce data-acquisition time. The time required for mapping the whole gap-area of the cyclotron magnet is ∼60 min. The relative measurement error for the averaged magnetic field along beam orbit is less than 0.02%. The cyclotron magnet has been corrected using field measurement data, and the achieved total phase excursion of the cyclotron after correction is less than ±15°, which is within the tolerance of ±20° for the total phase excursion.

In this paper, we introduce an efficient three‐dimensional magnetic field mapping system for a Deflection Yoke (DY) in Cathode‐Ray Tube (CRT). A three‐axis Hall probe mounted in a small cylindrical bar and three‐stepping motors placed in a non‐magnetic frame were utilized for the mapping. Prior to the mapping starts, the inner contour of DY was measured by a laser sensor to make a look‐up table for inner shape of DY. Three‐axis magnetic fields are then digitized by a three‐dimensional Hall probe. The results of the mapping can be transformed into various output formats such as multipole harmonics of magnetic fields. Field shape in one, two and three‐ dimensional spaces can also be displayed. In this paper, we present the features of this mapping device and some analysis results.

Pohang Accelerator Laboratory (PAL) is developing a Multipole Wiggler (MPW14) to utilize high-energy (B30 keV) synchrotron radiation at Pohang Light Source (PLS). The MPW14 is a hybrid type device to achieve maximum peak flux density and wide beam fan that can serve two beamlines. PLS MPW14-features period of 14 cm, minimum gap of 14 mm, 20 full field periods, maximum flux density of 2.06 T, 3036 mm total magnetic structure length. The peak flux density is very high compared to the other wigglers of similar pole gap and the period. The high peak flux density was possible using advanced new magnetic material and optimized magnetic geometry. The MPW14 will be used in hard X-ray region of 10–30 keV at 2.5 GeV electron energy. The total photon power is 6.19kW and the peak power density is 5.27 kW/mrad 2 at 2.5 GeV, 150 mA. To withstand the big magnetic loads with minimum deflections, C-type support structure is designed with detailed FEM structural analysis. In this article, all the conceptual design efforts for the PLS MPW14 wiggler will be described. r 2001 Elsevier Science B.V. All rights reserved. PACS: 41.85.L

Pohang Accelerator Laboratory is developing an Elliptically Polarized Undulator (EPU6) to utilize the polarized synchrotron radiation at Pohang Light Source (PLS). EPU6 is an Apple-II type elliptical undulator which changes the polarization of the field by translating the magnet arrays. EPU6 features period of 6 cm, minimum gap of 19 mm, 25 full field periods, maximum vertical flux density of 0.69 T, maximum horizontal flux density of 0.45 T, and 1575 mm total magnetic structure length. In this article, the design, fabrication, the measurement and correction efforts for PLS EPU6 undulator are described.

To examine the impact of amenorrhea on bone mineral density in women of reproductive age, we performed a cross sectional study in 190 amenorrheic women, comprising 113 premature ovarian failure, 27 primary hypothalamic amenorrhea, 38 hyperprolactinemia and 12 Sheehan's syndrome. Measurement of bone mineral density was carried out using dual photon absorptiometry at four sites: femur neck, ward's triangle, trochanter and spine (L2–4) and we compared the result with that of 163 normal-cycle control women with age matched. Bone mineral densities was significantly low in patients with primary hypothalamic amenorrhea and premature ovarian failure at all four sites. In those with hyperprolactinemia a decrease in bone mineral density was noted at femur neck and spine while those with Sheehan's syndrome is associated with decreased bone density at femur neck, ward's triangle and trochanter. The degree of bone loss and the affected sites seems differ depending on the type of amenorrhea. In patients with primary hypothalamic amenorrhea, significant bone loss was already noted at all four sites by age 20. The decrement in bone density continued rapidly during the early twenties up to age 25 and then slowed after age 25. In those with premature ovarian failure with secondary amenorrhea there were no decrease in bone mineral density within the first year after onset of amenorrhea, however, in the subsequent 2 years, the reduction in BMD was rapid and thereafter the reduction slowed remarkably. The BMD in this study positively correlated with the body mass index and negatively with the phosphorus intake.

In this paper, we derive a kind of classification of binary signal set by adopting Hadamard equivalence of binary matrices. We propose a fast algorithm for checking the Hadamard equivalence for general binary matrices, and give an intuitive analysis on its time complexity. For this, we define Hadamard-equivalence on the set of binary matrices, and a function which induces a total order on them. With respect to this order relation, we define the minimal element which is used as a representative of an equivalence class. We applied the proposed algorithm to binary matrices of smaller sizes, and show the results. Finally, we discuss a new combinatorial problem of counting the number of and enumerating all the inequivalent binary minimal matrices of size m × n, and show the solutions for small sizes, leaving many of the observed properties as open problems.

A prototype Silicon-Tungsten electromagnetic calorimeter (ECAL) for an International Linear Collider (ILC) detector was installed and tested during summer and autumn 2006 at CERN. The detector had 6480 silicon pads of dimension 1x1 cm^2. Data were collected with electron beams in the energy range 6 to 45 GeV. The analysis described in this paper focuses on electromagnetic shower reconstruction and characterises the ECAL response to electrons in terms of energy resolution and linearity. The detector is linear to within approximately the 1% level and has a relative energy resolution of (16.6 +- 0.1)/ \sqrt{E(GeV}) + 1.1 +- 0.1 (%). The spatial uniformity and the time stability of the ECAL are also addressed., 21 pages, 17 figs

The 100 MeV PEFP (Proton Engineering Frontier Project) proton linac has two proton beam extraction lines for user experiment. Each extraction line has 5 beamlines and has 2.5 Hz operating frequency. An AC switching magnet is used to distribute the proton beam to the 5 beam-lines, An AC switching magnet is excited by PWM-controlled bipolar switching-mode converters. This converter is designed to operate at ± 350A, 2.5 Hz programmable current step output. The power supply is employed IGBT modules and has been controlled by a Digital Signal Processor (DSP). This paper describes the design and test results of the power supply.

The PEFP (Proton Engineering Frontier Project) proton linac is designed to have two proton beam extraction lines at the 20-MeV and 100-MeV end. The 20-MeV extraction line is branched out into 5 beamlines by using the switching magnet. The magnet bends the proton beam by +20, +10, 0, -10, -20 degrees, respectively, and has an AC frequency of 2.5 Hz with a programmable ac power supply. It employs an H-shape, 0.45 T magnetic fields, 500 mm effective length, and 50 mm pole gap. Laminated steel of 0.5 mm reduces the eddy currents in the yoke, but some heat radiation from the stainless steel of vacuum chamber is inevitable. This paper presents the magnet specification and primary design.