PRESSURE MEASUREMENT OF 10-(10) TO 10(-12) NONRESONANT MULTIPHOTON IONIZATION

In order to increase the ion-detection efficiency of the pressure meas urement method using nonresonant multiphoton ionization, an ion-detect ion head was improved. Using this head, pressure measurements were car ried out for H-2 and Xe in the extreme high vacuum region. As a result , for H-2, by optimizing an incident ion energy, the efficiency increa sed by a factor of about 2.5. For Xe, without optimizing the incident ion energy, if increased by a factor of about 1.5. Copyright (C) 1996 Elsevier Science Ltd.