T Matsubara

University of Hyogo, Kōbe-shi, Hyogo-ken, Japan

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Publications (25)17.61 Total impact

  • T. Mitsui, T. Matsubara, Y. Hisaoka, Y. Shoji
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    ABSTRACT: A direct-drive pulse septum magnet has been in operation for injection of a 1 GeV electron beam at synchrotron light source ring NewSUBARU. Its nominal field is 0.35 T with waveform of 0.92 ms half-sine. Its stray field was measured using the stored electron beam and found to be different from the original design, probably because of an alignment error of the septum current sheet. In the data analysis, the stray field was separated in two components. One component had the expected normal field symmetry, and the other had an unexpected opposite field symmetry. As reported here, a correction coil system for the stray field was designed on the basis of measurements using the stored electron beam. The magnetic field produced by the correction coil was calculated with the field calculation code OPERA-3d. With this correction system, the stray field with the opposite symmetry was reduced from 213 muTm (Tesla meter) maximum to 8 muTm maximum.
    IEEE Transactions on Applied Superconductivity 07/2008; · 1.32 Impact Factor
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    ABSTRACT: To compare the effectiveness of scleral buckling to vitrectomy for the treatment of rhegmatogenous retinal detachment (RRD) due to equatorial retinal tears. Forty-six patients (46 eyes) > or =50 years of age with RRD due to equatorial retinal tears were studied. One group of 23 patients was selected by the randomized envelope method to be treated by scleral buckling and a second group of 23 to be treated by vitrectomy. The rate of retinal reattachment, the visual acuity, optical coherence tomography findings, and postoperative complications were determined. In addition, a questionnaire was filled out by the patients on their subjective assessment of the surgery and recovery. The rate of retinal reattachment was identical in the two groups. The postoperative visual acuity, the number of patients with visual acuity > or =0.8 and the mean visual acuity were significantly better in the vitrectomy group (chi-squared and Mann-Whitney U tests, P < 0.05) within 12 months after surgery. At 24 and 36 months, the differences in the visual acuity were not significant. The answers to the questionnaire given by the patients in the vitrectomy group suggested that their surgical experiences and visual recovery were better than those of patients in the scleral buckling group. In patients > or =50 years of age, vitrectomy was more effective than scleral buckling for obtaining good visual acuity in the short term.
    Japanese Journal of Ophthalmology 01/2007; 51(5):360-7. · 1.80 Impact Factor
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    ABSTRACT: We treated an adult patient with traumatic glaucoma who exhibited dramatic elasticity in the topography of the optic nerve head, as shown in a Heidelberg Retina Tomograph (HRT) examination after filtering surgery. A 41-year-old man came to us with a right eye injury following an external blow. At the first examination, visual acuity was 0.4 (1.2) and intraocular pressure (IOP) was 11 mmHg in both eyes. Cells in the anterior chamber and angle dialysis were noted in all quadrants of the right eye, but there was no hyphema. Two weeks later, the patient returned to our hospital with pain in the right eye and a headache. Visual acuity in the right eye had decreased to 0.06 (0.1) and IOP was 50mmHg. A cilioconjunctival injection and corneal edema were observed. The patient was treated with medications, but IOP was uncontrollable and the optic disc cupping in the right eye was enlarged. Further, values for Cup Disc Area Ratio (C/D; 0.553) and Cup Volume (CV; 0.548) in the right eye were larger than those of the left (0.287 and 0.168, respectively) in an HRT examination. We performed a non-penetrating trabeculectomy 5 weeks after the injury. Two weeks after surgery, IOP was lowered to 7 mmHg, and C/D 0.122) and CV (0.062) were improved. Six months after the procedure, C/D (0.304) and CV (0.202) were nearly the same as those of the left eye (0.292 and 0.144). Although the duration of high IOP was short, high elasticity in the optic disc morphology of this adult case was shown quantitatively in an HRT examination.
    Nippon Ganka Gakkai zasshi 10/2005; 109(9):613-8.
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    ABSTRACT: This paper confirms the occurrence of RF synchronized injection from SPring‐8 Linac to the NewSUBARU storage ring. NewSUBARU is a 1.5 GeV storage ring with injection energy of 1.0 GeV. Besides the 1.5 GeV user mode, the ring is often operated at 1.0 GeV for EUV users with the so‐called top‐up injection mode. In this experiment, we use a new synchronization method developed at SPring‐8, wherein an instantaneous synchronization between NewSUBARU RF (500 MHz) and Linac RF (2856 MHz) enables a buckets‐to‐bucket beam transfer. This is one of the key technologies of top‐up operations in a storage ring that uses a linac as an injector. The RF clock and timing trigger signal are sent to the Linac from NewSUBARU, and this clock is used to delay units in order to maintain good synchronicity. This works as a standard because it has a system to compensate for transfer‐time drift. The arbitrary waveform generator is another key module. It produces a clock 1/32 of that of the Linac RF using the NewSUBARU RF clock. With this system, we eliminated beam loss at the injection due to spillage from the ring RF bucket. © 2004 American Institute of Physics
    AIP Conference Proceedings. 05/2004; 705(1):53-56.
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    British Journal of Ophthalmology 03/2004; 88(2):302-3. · 2.81 Impact Factor
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    ABSTRACT: The present study was performed to clarify the long-term natural history of polypoidal choroidal vasculopathy (PCV). Prospective, consecutive observational case series. Fourteen eyes of 12 consecutive patients with PCV were prospectively followed in our clinic for at least 2 years without any treatment after a first visit to the clinic between February 1996 and November 1998. All patients underwent complete ophthalmologic examination, color fundus photography, and fluorescein and indocyanine green (ICG) angiography at regular intervals. Inclusion criteria were as follows: eyes had serous and/or hemorrhagic pigment epithelium detachment (PED) and retinal detachment in the posterior pole, and ICG angiography revealed a branching vascular network with polypoidal dilations at the terminals of the network. Exclusion criteria were as follows: other diseases such as exudative age-related macular degeneration, high myopia, angioid streaks, and presumed ocular histoplasmosis syndrome, and patients who previously underwent any ocular surgery. Patients were followed for mean of 39.9 months (range, 24-54 months). PCV was present in 10 (83%) men and two women and in the elderly (mean age 68.1 years), usually unilateral (83%) with vascular lesions located at the macula (93%). The PCV manifested in two patterns, exudative and hemorrhagic. In the exudative pattern, serous PED and retinal detachment were predominant at the macula. The hemorrhagic pattern was characterized by hemorrhagic PED and subretinal hemorrhage at the macula. ICG angiography revealed polypoidal choroidal neovascularization that was changeable in appearance and repeatedly grew and spontaneously regressed, but the vascular network persisted. In some eyes, a collection of small aneurysmal dilations of vessels resembling a cluster of grapes appeared and all of them had marked bleeding and leakage and worse outcome. Polypoidal choroidal vasculopathy is a long persistent chronic disease and the patients had a variable course. Fifty percent of the patients had a favorable course. In the remaining half of the patients, the disorder persisted for a long time with occasional repeated bleeding and leakage, resulting in macular degeneration and visual loss. Eyes with a cluster of grapes-like polypoidal dilatations of the vessels had a high risk for severe visual loss.
    American Journal of Ophthalmology 06/2002; 133(5):639-48. · 4.02 Impact Factor
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    ABSTRACT: PURPOSE: The present study was performed to clarify the long-term natural history of polypoidal choroidal vasculopathy (PCV).DESIGN: Prospective, consecutive observational case series.METHODS: Fourteen eyes of 12 consecutive patients with PCV were prospectively followed in our clinic for at least 2 years without any treatment after a first visit to the clinic between February 1996 and November 1998. All patients underwent complete ophthalmologic examination, color fundus photography, and fluorescein and indocyanine green (ICG) angiography at regular intervals. Inclusion criteria were as follows: eyes had serous and/or hemorrhagic pigment epithelium detachment (PED) and retinal detachment in the posterior pole, and ICG angiography revealed a branching vascular network with polypoidal dilations at the terminals of the network. Exclusion criteria were as follows: other diseases such as exudative age-related macular degeneration, high myopia, angioid streaks, and presumed ocular histoplasmosis syndrome, and patients who previously underwent any ocular surgery.RESULTS: Patients were followed for mean of 39.9 months (range, 24–54 months). PCV was present in 10 (83%) men and two women and in the elderly (mean age 68.1 years), usually unilateral (83%) with vascular lesions located at the macula (93%). The PCV manifested in two patterns, exudative and hemorrhagic. In the exudative pattern, serous PED and retinal detachment were predominant at the macula. The hemorrhagic pattern was characterized by hemorrhagic PED and subretinal hemorrhage at the macula. ICG angiography revealed polypoidal choroidal neovascularization that was changeable in appearance and repeatedly grew and spontaneously regressed, but the vascular network persisted. In some eyes, a collection of small aneurysmal dilations of vessels resembling a cluster of grapes appeared and all of them had marked bleeding and leakage and worse outcome.CONCLUSION: Polypoidal choroidal vasculopathy is a long persistent chronic disease and the patients had a variable course. Fifty percent of the patients had a favorable course. In the remaining half of the patients, the disorder persisted for a long time with occasional repeated bleeding and leakage, resulting in macular degeneration and visual loss. Eyes with a cluster of grapes-like polypoidal dilatations of the vessels had a high risk for severe visual loss.
    American Journal of Ophthalmology - AMER J OPHTHALMOL. 01/2002; 133(5):639-648.
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    ABSTRACT: Purpose: To determine the histological localization of indocyanine green (ICG) in the healthy rat eye and to correlate this with ICG angiographic findings.Methods: After intravenous ICG dye injection, the rat eyes were enucleated and processed by freeze-substitution fixation with acetone. The tissue sections were stimulated with an 805-nm diode laser and observed with an infrared microscope with an intensified charge coupled device camera. The histological examinations of ICG localization were correlated with the ICG angiographic images.Results: ICG dye did not leak from the retinal and iris vessels. However, in the choroid, extravasation of ICG from the choriocapillaris was observed. The extravascular ICG from the choriocapillaris slowly diffused to the choroidal stroma but did not diffuse to the neurosensory retina through the retinal pigment epithelium.Conclusion: Change in the localization of ICG in ocular tissue was demonstrated in the ICG angiographic findings. These results help to interpret clinical ICG angiographic findings.
    Japanese Journal of Ophthalmology - JPN J OPHTHALMOL. 01/2000; 44(1):94-94.
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    ABSTRACT: To describe the vascular nature and clinical features of idiopathic polypoidal choroidal vasculopathy in Japanese patients. Patients thought to have idiopathic polypoidal choroidal vasculopathy were examined with binocular ophthalmoscopy, slitlamp biomicroscopy with a contact lens, fluorescein angiography, and indocyanine green angiography. From January 1993 to December 1997, 35 eyes in 32 patients were diagnosed as having idiopathic polypoidal choroidal vasculopathy. Men were predominantly affected (22 patients [69%]). Most patients were unilaterally involved (29 patients [91%]) and elderly, with a mean age of 65.7 years (range, 44-82 years). Ocular manifestations were relatively mild, with serous or hemorrhagic detachments of the retinal pigment epithelium and neurosensory retina in the posterior pole. Most patients had a favorable course, although some experienced recurrence, and a few eyes developed disciform scarring. In all patients, indocyanine green angiograms demonstrated branching vascular networks with polypoidal dilations at terminals of the network beneath the retinal pigment epithelium. These lesions were mostly in the macula (33 eyes [94%]), with a few in the peripapillary area. Idiopathic polypoidal choroidal vasculopathy in Japanese patients differs from that in American patients. It seems that this disorder occurs in elderly Japanese patients and should be treated as a distinct clinical entity. It is probably a peculiar form of choroidal neovascularization beneath the retinal pigment epithelium. We propose the term "polypoidal choroidal neovascularization" for this disorder.
    Archives of Ophthalmology 09/1999; 117(8):1035-42. · 4.49 Impact Factor
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    ABSTRACT: To determine the histological localization of indocyanine green (ICG) in the healthy rat eye and to correlate this with ICG angiographic findings. After intravenous ICG dye injection, the rat eyes were enucleated and processed by freeze-substitution fixation with acetone. The tissue sections were stimulated with an 805-nm diode laser and observed with an infrared microscope with an intensified charge coupled device camera. The histological examinations of ICG localization were correlated with the ICG angiographic images. ICG dye did not leak from the retinal and iris vessels. However, in the choroid, extravasation of ICG from the choriocapillaris was observed. The extravascular ICG from the choriocapillaris slowly diffused to the choroidal stroma but did not diffuse to the neurosensory retina through the retinal pigment epithelium. Change in the localization of ICG in ocular tissue was demonstrated in the ICG angiographic findings. These results help to interpret clinical ICG angiographic findings.
    Nippon Ganka Gakkai zasshi 08/1999; 103(7):497-505.
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    ABSTRACT: We used N-methyl-N-nitrosourea (MNU) to induce chorioretinopathy as a model of retinitis pigmentosa, and compared the histological localization of indocyanine green (ICG) with ICG angiographic features. Brown-Norway pigmented rats received a single intraperitoneal injection of MNU (75 mg/kg body weight). At 3 and 21 days after treatment, we compared ICG angiographic findings with histological localization of ICG in the retina and choroid. Histological localization of ICG was observed with an infrared light microscope. 3 days after treatment, destruction of the photoreceptor cells and photoreceptor segments had developed, and the retinal pigment epithelial cells (RPEs) were also damaged. In ICG angiography, diffuse hyperfluorescence was evident. In histological localization of ICG, RPEs were stained by ICG, and ICG was seen in the sensory retina through the damaged RPEs. At 21 days after treatment, the inner nuclear layer directly contact with the choroid. The photoreceptor cells, RPEs and choriocapillaris had disappeared. In ICG angiography, hypofluorescence was seen in the chorioretinal atrophic area. In histological localization of ICG, there was no ICG in the atrophic area, but ICG leaked from the remaining choriocapillaris into the neighboring sensory retina. These results support the precise interpretation of ICG angiographic findings in clinical use.
    Nippon Ganka Gakkai zasshi 08/1999; 103(7):489-96.
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    ABSTRACT: To clarify the pathophysiology of multifocal posterior pigment epitheliopathy (MPPE), or bullous retinal detachment (RD)-an unusual manifestation of central serous chorioretinopathy (CSC)-we evaluated indocyanine green (ICG) angiographic findings of patients with MPPE. Indocyanine green angiography was performed on 45 eyes of 26 patients with MPPE in our clinic during a 4-year period and compared with clinical and fluorescein angiographic (FA) findings. Ophthalmoscopically, in the posterior pole there were multiple yellowish-white retinal exudations, associated with flat, serous RD and bullous RD in the lower periphery. Fluorescein angiography demonstrated multiple massive leakages from the choroid into the subretinal space. These leakage sites corresponded to the retinal exudations. Indocyanine green angiography showed hyperfluorescence in the posterior pole of the choroid. The hyperfluorescence was first seen in the middle phase and became prominent in the late phase. This finding seems to be due to extravasation from the choriocapillaris. After laser photocoagulation of the leakage sites seen on FA, the leakages stopped and the retinal exudations and RD were resolved. Indocyanine green angiography, however, revealed hyperfluorescence in the posterior pole that was seen in active stage. These ICG angiographic findings for MPPE show that hyperpermeability of the choroidal vessels may be the primary causative lesion. This is followed by an intrastromal accumulation of the extravasated choroidal fluid, which may be subclinical. Involvement of the retinal pigment epithelium may be secondary, and then the disease becomes manifest with RD. In MPPE, a severe form of CSC, the retinal pigment epithelium is involved extensively and widely, and prognosis is unfavorable. We conclude that MPPE and CSC represent opposite ends of a common morbid spectrum.
    Retina 02/1999; 19(1):12-21. · 3.18 Impact Factor
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    ABSTRACT: We performed an experimental study on choroidal circulatory disturbance to clarify basic problems about interpretation of retino-choroidal lesions in indocyanine green fluorescence angiography (ICG angiography). We severed the posterior ciliary arteries to produce choroidal circulatory disturbance. Fluorescein angiography and ICG angiography were performed at one week, and one month after occlusion. These findings were compared with histopathological findings. One week after occlusion, the area of choroidal infarct showed occlusion of choriocapillaris and proliferation of the retinal pigment epithelial (RPE) cells, this area showed hypofluorescence in the early phase ICG angiography. The hypofluorescence area increased in the late phase. One month after occlusion, the lesion showed loss of choriocapillaris at the center and proliferation of fibroblast-like cells at the edge of the lesion. The subretinal strand showed hyperfluorescence in late phase ICG angiography. Proliferated RPE cells masked ICG fluorescence in the late phase. Fibroblast-like cells showed tissue staining. When reading ICG angiography, we have to take into account that the ICG angiogram is greatly modified by condition of the RPE.
    Nippon Ganka Gakkai zasshi 03/1997; 101(2):127-33.
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    ABSTRACT: We performed an experimental study on choroidal circulatory disturbance to clarify basic problems about interpretation of retino-choroidal lesions in indocyanine green fluorescence angiography (ICG angiography). We severed all of the posterior temporal ciliary arteries, to produce choroidal circulatory disturbance. Fluorescein angiography and ICG angiography were performed using scanning laser ophthalmoscope immediately, and 2 days after occlusion. These findings were compared with histopathological findings from the same specimen. Immediately after occlusion, choroidal vessels were filled with the red blood cells in the lesion that showed hypofluorescence in both types of angiography. Two days after occlusion, the fundus had a grayish white edematous appearance which was similar to choroidal infarction. The retinal pigment epithelial cells. (RPEs) in infarcted lesion progressed to liquefied necrosis. Fluorescein angiography showed hyperfluorescence in the lesion, and ICG angiography showed hypofluorescence in the early phase, but hyperfluorescence at the margin of the lesion in the late phase. This result showed that damaged RPEs were stained by ICG dye. In reading ICG angiography, we have to consider that the ICG angiogram is greatly modified by the condition of the RPEs.
    Nippon Ganka Gakkai zasshi 02/1997; 101(1):12-8.
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    ABSTRACT: One hundred forty eyes with choroidal neovascularization (ChNV) in age-related macular degeneration were examined with fluorescein and indocyanine green (ICG) angiography. ChNVs covered with subretinal hemorrhage, and ChNVs with retinal pigment epithelial (RPE) detachment were demonstrated at a higher rate and more clearly with ICG angiography than with fluorescein angiography. On the other hand, ChNVs in serous retinal detachment, and in disciform lesions were demonstrated more clearly with fluorescein angiography than with ICG angiography. These results show that ICG angiography is valuable for delineating "occult ChNVs" with subretinal hemorrhage or RPE detachment in age-related macular degeneration.
    Nippon Ganka Gakkai zasshi 11/1996; 100(10):790-7.
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    ABSTRACT: We performed experiments in 20 monkey eyes in order to clarify basic problems about interpretation of indocyanine green fluorescence angiography (ICG angiography). We severed the temporal group of posterior ciliary arteries to produce choroidal circulatory disturbance. ICG angiography was performed immediately, and 2 days, 4 days, and 2 weeks later. Following each ICG angiography, the eye was studied by plastic vascular cast technique with scanning electron microscopy. Immediately after occlusion, ICG angiography showed filling defect in the temporal choroidal hemisphere during the early phase. In the later phase, this area was gradually filled by the dye from choroidal arteries in the nasal hemisphere and the anterior ciliary arteries. Vascular cast preparations showed filling defect in the temporal choroidal hemisphere, corresponding with the early ICG angiogaphic findings. Both filling delay in ICG angiography and filling defect in vascular casts improved daily after occlusion. Two weeks after occlusion, The area of choroidal infarct temporal to the macula turned into chorioretinal atrophy. This area showed hypofluorescence in the early-phase ICG angiography and filling defect of the choriocapillaris in plastic casts. The early-phase ICG angiographic findings thus corresponded well with observations of vascular casts. We conclude that ICG angiography correctly reflects the actual circulatory disturbances in the choroid.
    Nippon Ganka Gakkai zasshi 04/1996; 100(3):201-7.
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    ABSTRACT: The ultrastructure of experimentally induced choroidal neovascularization was studied in correlation with dye leakage in indocyanine green (ICG) infrared fluorescence angiography. Newly formed vessels which demonstrated leakage of ICG extended into the subretinal space without enclosure of retinal pigment epithelium (RPE), and the endothelial cells were immature. Choroidal neovascularization which did not demonstrate leakage of ICG was enclosed by RPE without retinal detachment, and the endothelial cells were mature. The newly formed vessels with immature endothelium in the subretinal space that were covered with multiple layers of RPE demonstrated no leakage. These results show that ICG leaks form choroidal neovascularization which has immature vessels that are not enclosed by RPE and that extend into the subretinal space.
    Nippon Ganka Gakkai zasshi 09/1995; 99(8):878-88.
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    ABSTRACT: Indocyanine green fluorescence angiography (ICG angiography) can reveal choroidal circulation, and so it is used to observe uveitis. We examined 29 eyes of 15 patients with Harada disease using ICG angiography. In the early phase, filling delay of choroidal circulation was the most remarkable finding in cases with flat retinal detachment in the posterior pole. In the early to late phase choroidal vessels were indistinct, and speckled hypofluorescence on the diffuse background fluorescence was seen. Leakage from the choroid into the subretinal space was seen in ICG angiography at the same leak points seen in fluorescein angiography. In 3 patients, the area of retinal detachment showed hypofluoresence in the late phase. Areas of Dalen-Fuchs spots showed hypofluorescence. ICG angiography clearly revealed severe disturbance of choroidal circulation in Harada disease, and filling delay of the choroidal circulation and indistinct choroidal vessels correlated with the severity of this disease. ICG angiography helps to evaluate the pathology of Harada disease clinically.
    Nippon Ganka Gakkai zasshi 10/1994; 98(9):852-7.
  • T Matsubara, M Uyama, J Kozaki, A Ohira
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    ABSTRACT: A 78-years-old man suffered from sympathetic ophthalmia. He had been treated with 5-fluorouracil (5-FU) for metastasis of colon cancer in the liver. He received a perforating eye injury in the left eye thereafter the eye became phthisic. Two months after the injury, he noticed visual disturbance in the right eye. He was treated with large doses of systemic corticosteroid after a diagnosis of uveitis of the right eye, but the visual acuity of the right eye became worse. The eye showed non-specific diffuse uveitis. A diagnosis of sympathetic ophthalmia was made from previous history and ocular findings. We enucleated the injured eye and continued the systemic corticosteroid. Then the right eye improved. Histopathological examination of the enucleated eye revealed the choroid was infiltrated with a granulomatous lesion of lymphocytes and epithelioid cells. HLA typing showed DR4, DR8, DR52, DR53, and DQ1, and we made a final diagnosis of sympathetic ophthalmia. It is probable that the clinical findings were modified by the 5-FU treatment and the patient's advanced age.
    Nippon Ganka Gakkai zasshi 04/1994; 98(3):309-14.
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    T Matsubara, S Hisao, Y Shoji, T Asaka, S Suzuki
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    ABSTRACT: We measured beam parameters of the linac using a streak camera in the storage ring. The SPring-8 linac is an injector, which supplies 1.0-GeV electron beam to "NewSUBARU". The synchrotron radiation facility NewSUBARU is a 1.5-GeV storage ring at the SPring-8 site. We observed a synchrotron oscillation of the injection beam in the storage ring using a streak camera. We got energy distribution and energy deviation of the injection beam from the storage ring energy for each linac bunch in a macro pulse. We also clarified an effect of the Energy Compression System (ECS) on linac beam.

Publication Stats

359 Citations
17.61 Total Impact Points

Institutions

  • 2008
    • University of Hyogo
      • Laboratory of Advanced Science and Technology for Industry (LASTI)
      Kōbe-shi, Hyogo-ken, Japan
  • 1994–2007
    • Kansai Medical University
      • Department of Ophthalmology
      Moriguchi, Ōsaka, Japan
  • 2004
    • Himeji Institute of Technology
      Himezi, Hyōgo, Japan