摘要:

A high pressure optical cell of large aperture has been constructed for use in pressure broadening studies of gasesin the infrared region of the spectrum. The cell is tight at both vacuum and 1000 psi and is constructed of stainlesssteel with 3×1-in. calcium fluoride windows. A method of measuring short path length cell spacing to an accuracyof 1% using an optical “butterfly” is described. Data are presented on the pressure-induced distortion of the cellpath length for calcium fluoride windows as well as optical glass windows.

ISSN:0034-6748    

DOI:10.1063/1.1931242

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

The effect whichSiF4,SO2, andSF6have on the plateau and the pulse size distribution of a proportional counterwere investigated.SiF4was tested at three pressures, 30, 45, and 60 cm, ofBF3and its effect was found to be independentof the counter pressure for the range of value considered. From the variation in the plateau, the attachmentprobability forSiF4was calculated to beh = 1.485×10−5and its cross section for attachment to be&sgr;a = 5.12×10−20 cm2. The amount of these gases permitted, without the counter being affected beyond the limitsof tolerance which are set up, were found to be 0.04% forSiF4, 0.01% forSO2, and2.0×10−6%forSF6.

ISSN:0034-6748    

DOI:10.1063/1.1931243

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

A simple recording electromagnetic weighing balance has been constructed and operated as a moisture sorptionbalance and as a flash pyrolysis weight-loss balance. A weight hanging at one end of a lever arm is equilibrated bythe counter torque resulting from an armature (same axis of rotation as the lever arm) carrying an electric currentflowing perpendicular to a magnetic field. The current is supplied from a dc amplifier which is controlled by lightfalling on a phototube. These components are interconnected in a feedback loop so that the weight of the sample,the amount of light striking the phototube, and the magnitude of the counter torque current are all sustained indynamic equilibrium. The instrument has been operated over the 0- to 100-mg range and found to be linear andquite stable with a precision of 0.04 mg.

ISSN:0034-6748    

DOI:10.1063/1.1931244

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

The instrument described automatically maps two-dimensional contours of spatial intensity distributions (i.e.,iso-dose, iso-potential, etc.). A fast response detector is driven by two reversible motors, one a scan drive, theother an error compensation drive. Sequential alteration of the roles of the two motors provides complete mappingof continuous or discontinuous contours. Provisions are made to assure 1% recording accuracy. A remote readoutrecorder allows isolation of the pickup device. Maximum plotting speed is 36 in./min or about 5 min for a familyof ten contours in a 10×25-cm area.

ISSN:0034-6748    

DOI:10.1063/1.1931245

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

An instrument for measuring magnetic anisotropy by recording magnetic torque curves is described. The specialconstruction of the transducer which converts the torque exerted on the sample into an electric signal makes itpossible to avoid bearings, so that the instrument is essentially free of friction. The instrument is operated withcommercially available electronic apparatus and is suitable for routine measurements on large numbers of samples.The maximum sensitivity is 150 d cm per centimeter deflection of the recorder stylus.

ISSN:0034-6748    

DOI:10.1063/1.1931246

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

A lightweight inexpensive suntracker for balloon applications is described. The entire tracking system includingpower supplies for a 12-hr flight weighs 1.76 kg. The system has demonstrated in the laboratory a capability ofpointing a 1.42-kg load at the sun within ±0.12°. A very simple and reliable acquisition and tracking technique isemployed which uses no vacuum tubes or transistors.

ISSN:0034-6748    

DOI:10.1063/1.1931247

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

A flexible magnetic resonance spectrometer is described. Its transmission type microwave structure can be usedbetween 50 and 150 kMc. A modified Varian magnet gives a field of 28 000 gauss, homogeneous to 3 gauss over atypical sample area. A Dewar vessel fits into the34-in. magnet gap and permits cooling of the sample below the&lgr; point of helium. The millimeter waves are generated by backward wave oscillators, and harmonic conversion isused for the frequency measurement and control. A modification of the spectrometer makes possible the directmeasurement of line width and frequency of zero-field lines.

ISSN:0034-6748    

DOI:10.1063/1.1931248

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

A double focusing zero dispersion magnetic spectrometer has been constructed having the following properties:The spectrometer consists of two magnets, eachn≅0.25, 110° deflection, 30-in. radius of curvature, bending theparticles in the same sense. For the central momentump0, the useful solid angle&OHgr;0is ∼0.0055 sr with a possibilityof improvement to 0.01 sr. The momentum acceptance&Dgr;pis in excess of ±4% with a useful solid angle &OHgr; of ∼0.0015sr at the 4% points. For a point source and for the solid angles and momentum acceptances given, over 90% of thetrajectories terminate within a circle of 2-in. diameter at the focal plane.

ISSN:0034-6748    

DOI:10.1063/1.1931249

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

Operation of the Alvarez 4-in. hydrogen bubble chamber in a high-energy photon beam is described, the techniquesemployed in several modes of operation are discussed, and the corresponding bubble chamber conditions aretabulated. Reduction of electron background was accomplished by beam hardening and by using a Mylar beam-entrancewindow on the chamber.

ISSN:0034-6748    

DOI:10.1063/1.1931250

出版商:AIP    

年代:1960

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1931251

出版商:AIP    

年代:1960

数据来源: AIP