- CEM and SEM
- SEM 6M and SEM 6C
Secondary electron multipliers SEM-6M and SEM-6С
Channel secondary electron multiplier SEM-6 with electrostatic electron focusing and open input is intended for charged / neutral particles, UF and X-ray radiation registration.
Epoxy glue was excluded from manufacturing process of SEM-6M, intended for application in time-of-flight mass-spectrometry. Construction of the secondary-electron multiplier is entirely mechanical. Dark pulses are reduced. It is possible to use SEM-6М under 300ºС.
There are two modifications SEM-6:
- SEM-6M / mechanical mounting to housing;
- SEM-6C / glued joint to housing.
| Electrical Characteristics | |||
Parameter |
Dimension |
Minimum |
Maximum |
| Gain at ≤ 3300 V | - | 1×108 | - |
| Amplitude resolution at count rate up to 1×104pulse/s
and at U equal to gain 1×108 | - | - | 0,5 |
| Dark count rate | pulse/s | - | 0,5 * |
| Channel supply current at 4000 V | µA | 5 | 20 |
* The measurements are made in integral mode at discrimination level 0.1 from average SEM pulses height, at U corresponding to the gain not less than 1×108.
| Electrical Characteristics Changeable at Operational Process | ||
Parameter |
Dimension |
Value, maximum |
| Amplitude resolution | - | 0,8 |
| Supply voltage amplification at gain 1×108 | % | 15 |
| Absolute Maximum Ratings | ||
Parameter |
Dimension |
Value, maximum |
| Gain | - | 7×108 |
| Supply voltage | V | 4000* |
| Average output current | µA | 1** |
| Count rate | pulse/s | 105** |
* In order to increase gain operation at supply voltage higher than 4000 V is allowed. In such cases discrepancies in some parameters mentioned in specification (dark count rate, amplitude resolution and mean time to failure) may take place.
** Within not more than 30 minutes.
SEM must be operable after vacuum baking at 200°C at residual pressure not better than 1.33 × 10–3Pa (1×10–5 Torr.) during 5 hours. Net weight mustn’t be greater than 30 grammes.
Precious metals content per one product
Silver – 0,2750 gramme contains electroconductive past composition.
SEM component parts don’t contain nonferrous metals.
Warranties:
Warranty period: 4 years from the acceptance date.
Warranty life: providing specification terms and conditions, within the warranty period is 500 hrs.
SEM c-percentile storageability time at γ = 90%, providing storage conditions mentioned in specification is not less than 4 years.